Take-off Distance vs. Density Altitude Rate of Climb vs. Density Altitude EXTRAPOLATION OF CHART 16000 ABOVE 7000 FEET IS INVALID 14000 12000 7000 10000 Density altitude (feet)6000 8000 6000 Ground run5000 4000 Over 50 feet obstacle 2000 4000 Density altitude (feet) 0 3000 Rate of climb (feet per minute) 2000 2000 lb gross weight 1000 2200 lb gross weight 0 1980000000 760000 540000 312000000 0 4000 3500 3000 2500 2000 1500 1000 500 Take-off distance (feet) Figure 5-2. Performance chart examples. propeller performance, increase takeoff rolls and decrease Normal Takeoff climb performance. A more detailed discussion of density altitude and how it affects airplane performance can be A normal takeoff is one in which the airplane is headed into found in the Pilot’s Handbook of Aeronautical Knowledge the wind; there are times that a takeoff with a tail wind is (FAA-H-8083-25, as revised). necessary. However, the pilot must consult the POH/AFM to ensure the aircraft is approved for a takeoff with a tail All run up and pre-takeoff checklist items should be wind and that there is sufficient performance and runway completed before taxiing onto the runway or takeoff area. length for the takeoff. Also, the takeoff surfaces are firm As a minimum before every takeoff, all engine instruments and of sufficient length to permit the airplane to gradually should be checked for proper and usual indications, and accelerate to normal lift-off and climb-out speed, and there all controls should be checked for full, free, and correct are no obstructions along the takeoff path. movement. In addition, the pilot must make certain that the approach and takeoff paths are clear of other aircraft. At There are two reasons for making a takeoff as nearly into nontowered airports, pilots should announce their intentions the wind as possible. First, since the airplane depends on on the common traffic advisory frequency (CTAF) assigned airspeed, a headwind provides some of that airspeed even to that airport. When operating from a towered airport, before the airplane begins to accelerate into the wind. Second, pilots must contact the tower operator and receive a takeoff a headwind decreases the ground speed necessary to achieve clearance before taxiing onto the active runway. flying speed. Slower ground speeds yield shorter ground roll distances and allow use of shorter runways while reducing It is not recommended to take off immediately behind another wear and stress on the landing gear. aircraft, particularly large, heavily loaded transport airplanes, because of the wake turbulence that is generated. If an Takeoff Roll immediate takeoff is necessary, plan to minimize the chances For takeoff, use the rudder pedals in most general aviation of flying through an aircraft’s wake turbulence by avoiding airplanes to steer the airplane’s nose wheel onto the runway the other aircraft’s flightpath or rotate prior to the point at centerline to align the airplane and nose wheel with the which the preceding aircraft rotated. While taxiing onto the runway. After releasing the brakes, advance the throttle runway, select ground reference points that are aligned with smoothly and continuously to takeoff power. An abrupt the runway direction to aid in maintaining directional control application of power may cause the airplane to yaw sharply and alignment with the runway center line during the climb to the left because of the torque effects of the engine and out. These may be runway centerline markings, runway propeller. This is most apparent in high horsepower engines. lighting, distant trees, towers, buildings, or mountain peaks. As the airplane starts to roll forward, assure both feet are on 5-3
the rudder pedals so that the toes or balls of the feet are on The situation may be aggravated by the sluggish reaction of the rudder portions, not on the brake. At all times, monitor the airplane to these movements. The flight instructor must the engine instruments for indications of a malfunction during help the student learn proper response to control actions and the takeoff roll. airplane reactions. The instructor should always stress using the proper outside reference to judge airplane motion. For In nose-wheel type airplanes, pressures on the elevator takeoff, the student should always be looking far down the control are not necessary beyond those needed to steady it. runway at two points aligned with the runway. The flight Applying unnecessary pressure only aggravates the takeoff instructor should have the student pilot follow through lightly and prevents the pilot from recognizing when elevator control on the controls, feel for resistance, and point out the outside pressure is actually needed to establish the takeoff attitude. references that provide the clues for how much control movement is needed and how the pressure and response As the airplane gains speed, the elevator control tends to changes as airspeed increases. With practice, the student assume a neutral position if the airplane is correctly trimmed. pilot should become familiar with the airplane’s response to At the same time, the rudder pedals are used to keep the nose acceleration to lift off speed, corrective control movements of the airplane pointed down the runway and parallel to the needed, and the outside references necessary to accomplish centerline. The effects of engine torque and P-factor at the the takeoff maneuver. initial speeds tend to pull the nose to the left (Torque and P-Factor will be discussed in greater detail in later chapter). Lift-Off The pilot must use whatever rudder pressure is needed to Since a good takeoff depends on the proper takeoff attitude, correct for these effects or winds. Use aileron controls into it is important to know how this attitude appears and how it any crosswind to keep the airplane centered on the runway is attained. The ideal takeoff attitude requires only minimum centerline. The pilot should avoid using the brakes for pitch adjustments shortly after the airplane lifts off to attain steering purposes as this will slow acceleration, lengthen the speed for the best rate of climb (VY). [Figure 5-3] The the takeoff distance, and possibly result in severe swerving. pitch attitude necessary for the airplane to accelerate to VY speed should be demonstrated by the instructor and As the speed of the takeoff roll increases, more and more memorized by the student. Flight instructors should be aware pressure will be felt on the flight controls, particularly the that initially, the student pilot may have a tendency to hold elevators and rudder. If the tail surfaces are affected by the excessive back-elevator pressure just after lift-off, resulting propeller slipstream, they become effective first. As the speed in an abrupt pitch-up. continues to increase, all of the flight controls will gradually become effective enough to maneuver the airplane about its A Initial roll three axes. At this point, the airplane is being flown more than it is being taxied. As this occurs, progressively smaller rudder deflections are needed to maintain direction. The feel of resistance to the movement of the controls and B Takeoff attitude the airplane’s reaction to such movements are the only real indicators of the degree of control attained. This feel of resistance is not a measure of the airplane’s speed, but rather of its controllability. To determine the degree of controllability, the pilot must be conscious of the reaction of the airplane to the control pressures and immediately adjust the pressures as needed to control the airplane. The pilot must wait for the reaction of the airplane to the applied control pressures and attempt to sense the control resistance to pressure rather than attempt to control the airplane by movement of the controls. A student pilot does not normally have a full appreciation Figure 5-3. Initial roll and takeoff attitude. of the variations of control pressures with the speed of the airplane. The student may tend to move the controls through wide ranges seeking the pressures that are familiar and expected and, as a consequence, overcontrol the airplane. 5-4
Each type of airplane has a best pitch attitude for normal lift- indicator and neglect bank control of the airplane. Torque off; however, varying conditions may make a difference in the from the engine tends to impart a rolling force that is most required takeoff technique. A rough field, a smooth field, a evident as the landing gear is leaving the surface. hard surface runway, or a short or soft, muddy field all call for a slightly different technique, as will smooth air in contrast to During takeoffs in a strong, gusty wind, it is advisable that a strong, gusty wind. The different techniques for those other- an extra margin of speed be obtained before the airplane is than-normal conditions are discussed later in this chapter. allowed to leave the ground. A takeoff at the normal takeoff speed may result in a lack of positive control, or a stall, when When all the flight controls become effective during the the airplane encounters a sudden lull in strong, gusty wind, or takeoff roll in a nose-wheel type airplane, the pilot should other turbulent air currents. In this case, the pilot should allow gradually apply back-elevator pressure to raise the nose- the airplane to stay on the ground longer to attain more speed; wheel slightly off the runway, thus establishing the takeoff then make a smooth, positive rotation to leave the ground. or lift-off attitude. This is the “rotation” for lift off and climb. As the airplane lifts off the surface, the pitch attitude to hold Initial Climb the climb airspeed should be held with elevator control and Upon lift-off, the airplane should be flying at approximately trimmed to maintain that pitch attitude without excessive the pitch attitude that allows it to accelerate to VY. This is control pressures. The wings should be leveled after lift-off the speed at which the airplane gains the most altitude in the and the rudder used to ensure coordinated flight. shortest period of time. After rotation, the slightly nose-high pitch attitude should If the airplane has been properly trimmed, some back-elevator be held until the airplane lifts off. Rudder control should be pressure may be required to hold this attitude until the proper used to maintain the track of the airplane along the runway climb speed is established. Relaxation of any back-elevator centerline until any required crab angle in level flight is pressure before this time may result in the airplane settling, established. Forcing it into the air by applying excessive even to the extent that it contacts the runway. back-elevator pressure would only result in an excessively high-pitch attitude and may delay the takeoff. As discussed The airplane’s speed will increase rapidly after it becomes earlier, excessive and rapid changes in pitch attitude result in airborne. Once a positive rate of climb is established, the proportionate changes in the effects of torque, thus making pilot should retract the flaps and landing gear (if equipped). the airplane more difficult to control. It is recommended that takeoff power be maintained until reaching an altitude of at least 500 feet above the surrounding Although the airplane can be forced into the air, this is terrain or obstacles. The combination of VY and takeoff power considered an unsafe practice and should be avoided under assures the maximum altitude gained in a minimum amount normal circumstances. If the airplane is forced to leave the of time. This gives the pilot more altitude from which the ground by using too much back-elevator pressure before airplane can be safely maneuvered in case of an engine failure adequate flying speed is attained, the wing’s AOA may or other emergency. A pilot should also consider flying at become excessive, causing the airplane to settle back to the Vy versus a lower pitch for a cruise climb requires much runway or even to stall. On the other hand, if sufficient back- quicker pilot response in the event of a powerplant failure elevator pressure is not held to maintain the correct takeoff to preclude a stall. attitude after becoming airborne, or the nose is allowed to lower excessively, the airplane may also settle back to the Since the power on the initial climb is set at the takeoff power runway. This would occur because the AOA is decreased setting, the airspeed must be controlled by making slight pitch and lift diminished to the degree where it will not support adjustments using the elevators. However, the pilot should the airplane. It is important, then, to hold the correct attitude not fixate on the airspeed indicator when making these pitch constant after rotation or lift-off. changes, but should continue to scan outside to adjust the airplane’s attitude in relation to the horizon. In accordance As the airplane leaves the ground, the pilot must keep the with the principles of attitude flying, the pilot should first wings in a level attitude and hold the proper pitch attitude. make the necessary pitch change with reference to the natural Outside visual scans must be intensified at this critical point horizon and hold the new attitude momentarily, and then to attain/maintain proper airplane pitch and bank attitude. glance at the airspeed indicator to verify if the new attitude Due to the minimum airspeed, the flight controls are not as is correct. Due to inertia, the airplane will not accelerate or responsive, requiring more control movement to achieve decelerate immediately as the pitch is changed. It takes a little an expected response. A novice pilot often has a tendency time for the airspeed to change. If the pitch attitude has been to fixate on the airplane’s pitch attitude and/or the airspeed over or under corrected, the airspeed indicator will show a 5-5
speed that is higher or lower than that desired. When this • Failure to check engine instruments for signs of occurs, the cross-checking and appropriate pitch-changing malfunction after applying takeoff power. process must be repeated until the desired climbing attitude is established. Pilots must remember the climb pitch will be • Failure to anticipate the airplane’s left turning lower when the airplane is heavily loaded, or power is limited tendency on initial acceleration. by density altitude. • Overcorrecting for left turning tendency. When the correct pitch attitude has been attained, the pilot should hold it constant while cross-checking it against the • Relying solely on the airspeed indicator rather than horizon and other outside visual references. The airspeed developing an understanding of visual references and indicator should be used only as a check to determine if the tracking clues of airplane airspeed and controllability attitude is correct. during acceleration and lift-off. After the recommended climb airspeed has been established • Failure to attain proper lift-off attitude. and a safe maneuvering altitude has been reached, the pilot should adjust the power to the recommended climb setting • Inadequate compensation for torque/P-factor during and trim the airplane to relieve the control pressures. This initial climb resulting in a sideslip. makes it easier to hold a constant attitude and airspeed. • Overcontrol of elevators during initial climb-out and During initial climb, it is important that the takeoff path lack of elevator trimming. remain aligned with the runway to avoid drifting into obstructions or into the path of another aircraft that may be • Limiting scan to areas directly ahead of the airplane taking off from a parallel runway. A flight instructor should (pitch attitude and direction), causing a wing (usually help the student identify two points inline ahead of the runway the left) to drop immediately after lift-off. to use as a tracking reference. As long as those two points are inline, the airplane is remaining on the desired track. Proper • Failure to attain/maintain best rate-of-climb airspeed scanning techniques are essential to a safe takeoff and climb, (VY) or desired climb airspeed. not only for maintaining attitude and direction, but also for avoiding collisions near the airport. • Failure to employ the principles of attitude flying during climb-out, resulting in “chasing” the airspeed When the student pilot nears the solo stage of flight training, indicator. it should be explained that the airplane’s takeoff performance will be much different when the instructor is not in the Crosswind Takeoff airplane. Due to decreased load, the airplane will become airborne earlier and climb more rapidly. The pitch attitude While it is usually preferable to take off directly into the that the student has learned to associate with initial climb may wind whenever possible or practical, there are many instances also differ due to decreased weight, and the flight controls when circumstances or judgment indicate otherwise. may seem more sensitive. If the situation is unexpected, Therefore, the pilot must be familiar with the principles and it may result in increased tension that may remain until techniques involved in crosswind takeoffs, as well as those after the landing. Frequently, the existence of this tension for normal takeoffs. A crosswind affects the airplane during and the uncertainty that develops due to the perception of takeoff much as it does during taxiing. With this in mind, the an “abnormal” takeoff results in poor performance on the pilot should be aware that the technique used for crosswind subsequent landing. correction during takeoffs closely parallels the crosswind correction techniques used for taxiing. Common errors in the performance of normal takeoffs and departure climbs are: Takeoff Roll The technique used during the initial takeoff roll in a • Failure to review AFM/POH and performance charts crosswind is generally the same as the technique used in a prior to takeoff. normal takeoff roll, except that the pilot must apply aileron pressure into the crosswind. This raises the aileron on the • Failure to adequately clear the area prior to taxiing upwind wing, imposing a downward force on the wing into position on the active runway. to counteract the lifting force of the crosswind; and thus preventing the wing from rising. The pilot must remember • Abrupt use of the throttle. that since the ailerons and rudder are deflected, drag will increase; therefore, less initial takeoff performance should be expected until the airplane is wings-level in coordinated flight in the climb. 5-6
Apply full aileron into wind Rudder as needed for direction 18 Hold aileron into wind W Roll on upwind wheel IN Start roll Rudder as needed D Takeoff roll Hold aileron into wind Bank into wind Lift-off Rudder as needed to keeping heading Transition down runway Initial climb Transition from take-off slip to crab, and begin coordinated flight Wings level with a wind correction angle Rudder for coordinated flight Figure 5-4. Crosswind roll and takeoff climb. While taxiing into takeoff position, it is essential that the effect will not completely vanish; therefore, the pilot must pilot check the windsock and other wind direction indicators maintain some aileron pressure throughout the takeoff roll for the presence of a crosswind. If a crosswind is present, to keep the crosswind from raising the upwind wing. If the the pilot should apply full aileron pressure into the wind upwind wing rises, the amount of wing surface exposed to while beginning the takeoff roll. The pilot should maintain the crosswind will increase, which may cause the airplane this control position, as the airplane accelerates, until the to \"skip.\" [Figure 5-5] ailerons become effective in maneuvering the airplane about its longitudinal axis. As the ailerons become effective, the No Correction pilot will feel an increase in pressure on the aileron control. While holding aileron pressure into the wind, the pilot Wind should use the rudder to maintain a straight takeoff path. Proper Correction [Figure 5-4] Since the airplane tends to weathervane into the wind while on the ground, the pilot will typically apply Wind downwind rudder pressure. When the pilot increases power for takeoff, the resulting P-factor causes the airplane to yaw to the left. While this yaw may be sufficient to counteract the airplane’s tendency to weathervane into the wind in a crosswind to the right, it may aggravate this tendency in a crosswind to the left. In any case, the pilot should apply rudder pressure in the appropriate direction to keep the airplane rolling straight down the runway. As the forward speed of the airplane increases, the pilot Figure 5-5. Crosswind effect. should only apply enough aileron pressure to keep the airplane laterally aligned with the runway centerline. The rudders keep the airplane pointed parallel with the runway centerline, while the ailerons keep the airplane laterally aligned with the centerline. The crosswind component 5-7
This “skipping” is usually indicated by a series of very small simultaneous rudder input to maintain runway alignment. bounces caused by the airplane attempting to fly and then This will initially result in the aircraft to sideslip. However, settling back onto the runway. During these bounces, the as the aircraft establishes its climb, the nose should be turned crosswind also tends to move the airplane sideways, and into the wind to offset the crosswind, wings brought to level, these bounces develop into side-skipping. This side-skipping and rudder input adjusted to maintain runway alignment imposes severe side stresses on the landing gear and may (crabbing). [Figure 5-6] Firm and positive use of the rudder result in structural failure. may be required to keep the airplane pointed down the runway or parallel to the centerline. Unlike landing, the During a crosswind takeoff roll, it is important that the pilot runway alignment (staying over the runway and its extended hold sufficient aileron pressure into the wind not only to keep centerline) is paramount to keeping the aircraft parallel to the the upwind wing from rising but to hold that wing down so centerline. The pilot must then apply rudder pressure firmly that the airplane sideslips into the wind enough to counteract and aggressively to keep the airplane headed straight down the drift immediately after lift-off. runway. However, because the force of a crosswind may vary markedly within a few hundred feet of the ground, the pilot Lift-Off should check the ground track frequently and adjust the wind As the nose-wheel raises off of the runway, the pilot should correction angle, as necessary. The remainder of the climb hold aileron pressure into the wind. This may cause the technique is the same used for normal takeoffs and climbs. downwind wing to rise and the downwind main wheel to lift off the runway first, with the remainder of the takeoff roll The most common errors made while performing crosswind being made on that one main wheel. This is acceptable and takeoffs include the following: is preferable to side-skipping. • Failure to review AFM/POH performance and charts If a significant crosswind exists, the pilot should hold the main prior to takeoff. wheels on the ground slightly longer than in a normal takeoff so that a smooth but very definite lift-off can be made. This • Failure to adequately clear the area prior to taxiing allows the airplane to leave the ground under more positive onto the active runway. control and helps it remain airborne while the pilot establishes the proper amount of wind correction. More importantly, this procedure avoids imposing excessive side-loads on the landing gear and prevents possible damage that would result from the airplane settling back to the runway while drifting. As both main wheels leave the runway, the airplane begins to Wind drift sideways with the wind as ground friction is no longer a factor in preventing lateral movement. To minimize this 18 lateral movement and to keep the upwind wing from rising, the pilot must establish and maintain the proper amount of crosswind correction prior to lift-off by applying aileron pressure into the wind. The pilot must also apply rudder pressure, as needed, to prevent weathervaning. Initial Climb Figure 5-6. Crosswind climb flightpath. If a proper crosswind correction is applied, the aircraft will maintain alignment with the runway while accelerating to takeoff speed and then maintain that alignment once airborne. As takeoff acceleration occurs, the efficiency of the up-aileron will increase with aircraft speed causing the upwind wing to produce greater downward force and, as a result, counteract the effect of the crosswind. The yoke, having been initially turned into the wind, can be relaxed to the extent necessary to keep the aircraft aligned with the runway. As the aircraft becomes flyable and airborne, the wing that is upwind will have a tendency to be lower relative the other wing requiring 5-8
• Using less than full aileron pressure into the wind The ground effect causes local increases in static pressure, initially on the takeoff roll. which cause the airspeed indicator and altimeter to indicate slightly lower values than they should and usually cause • Mechanical use of aileron control rather than judging the vertical speed indicator to indicate a descent. As the lateral position of airplane on runway from visual airplane lifts off and climbs out of the ground effect area, clues and applying sufficient aileron to keep airplane the following occurs: centered laterally on runway. • The airplane requires an increase in AOA to maintain • Side-skipping due to improper aileron application. lift coefficient. • Inadequate rudder control to maintain airplane parallel • The airplane experiences an increase in induced drag to centerline and pointed straight ahead in alignment and thrust required. with visual references. • The airplane experiences a pitch-up tendency and • Excessive aileron input in the latter stage of the takeoff requires less elevator travel because of an increase in roll resulting in a steep bank into the wind at lift-off. downwash at the horizontal tail. • Inadequate drift correction after lift-off. • The airplane experiences a reduction in static source pressure and a corresponding increase in indicated Ground Effect on Takeoff airspeed. Ground effect is a condition of improved performance Due to the reduced drag in ground effect, the airplane may encountered when the airplane is operating very close to the seem to be able to take off below the recommended airspeed. ground. Ground effect can be detected and normally occurs However, as the airplane climbs out of ground effect below up to an altitude equal to one wingspan above the surface. the recommended climb speed, initial climb performance [Figure 5-7] Ground effect is most significant when the will be much less than at Vy or even Vx. Under conditions airplane maintains a constant attitude at low airspeed at low of high-density altitude, high temperature, and/or maximum altitude (for example, during takeoff when the airplane lifts gross weight, the airplane may be able to lift off but will off and accelerates to climb speed, and during the landing be unable to climb out of ground effect. Consequently, the flare before touchdown). airplane may not be able to clear obstructions. Lift off before attaining recommended flight airspeed incurs more drag, When the wing is under the influence of ground effect, there which requires more power to overcome. Since the initial is a reduction in upwash, downwash, and wingtip vortices. takeoff and climb is based on maximum power, reducing As a result of the reduced wingtip vortices, induced drag is drag is the only option. To reduce drag, pitch must be reduced reduced. When the wing is at a height equal to 1⁄4 the span, which means losing altitude. Pilots must remember that many the reduction in induced drag is about 25 percent. When airplanes cannot safely takeoff at maximum gross weight at the wing is at a height equal to ⁄1 10 the span, the reduction certain altitudes and temperatures, due to lack of performance. in induced drag is about 50 percent. At high speeds where Therefore, under marginal conditions, it is important that the parasite drag dominates, induced drag is a small part of the airplane takes off at the speed recommended for adequate total drag. Consequently, ground effect is a greater concern initial climb performance. during takeoff and landing. At takeoff, the takeoff roll, lift-off, and the beginning of the Ground effect is important to normal flight operations. If the initial climb are accomplished within the ground effect area. runway is long enough or if no obstacles exist, ground effect Takeoff in Ground Effect Area Ground effect is negligible when height is equal to wingspan Accelerate in ground Ground effect decreases effect to VX or VY quickly with height Ground effect decreases Airplane may fly at lower induced drag indicated airspeed Ground effect area Figure 5-7. Takeoff in-ground effect area. 5-9
can be used to the pilot’s advantage by using the reduced Takeoff Roll drag to improve initial acceleration. Taking off from a short field requires the takeoff to be started from the very beginning of the takeoff area. At this point, the When taking off from an unsatisfactory surface, the pilot airplane is aligned with the intended takeoff path. If the airplane should apply as much weight to the wings as possible during manufacturer recommends the use of flaps, they are extended the ground run and lift off, using ground effect as an aid, the proper amount before beginning the takeoff roll. This prior to attaining true flying speed. The pilot should reduce allows the pilot to devote full attention to the proper technique AOA to attain normal airspeed before attempting to fly out and the airplane’s performance throughout the takeoff. of the ground effect areas. The pilot should apply takeoff power smoothly and Short-Field Takeoff and Maximum continuously, without hesitation, to accelerate the airplane Performance Climb as rapidly as possible. Some pilots prefer to hold the brakes until the maximum obtainable engine revolutions per minute When performing takeoffs and climbs from fields where the (rpm) are achieved before allowing the airplane to begin its takeoff area is short or the available takeoff area is restricted takeoff run. However, it has not been established that this by obstructions, the pilot should operate the airplane at the procedure results in a shorter takeoff run in all light, single- maximum limit of its takeoff performance capabilities. To engine airplanes. The airplane is allowed to roll with its depart from such an area safely, the pilot must exercise full weight on the main wheels and accelerate to the lift-off positive and precise control of airplane attitude and airspeed speed. As the takeoff roll progresses, the pilot must adjust so that takeoff and climb performance result in the shortest the airplane’s pitch attitude and AOA to attain minimum drag ground roll and the steepest angle of climb. [Figure 5-8] The and maximum acceleration. In nose-wheel type airplanes, this pilot should consult and follow the performance section of the involves little use of the elevator control since the airplane AFM/POH to obtain the power setting, flap setting, airspeed, is already in a low drag attitude. and procedures prescribed by the airplane’s manufacturer. The pilot must have adequate knowledge in the use and Lift-Off effectiveness of the best angle-of-climb speed (VX) and the best rate-of-climb speed (VY) for the specific make and As VX approaches, the pilot should apply back-elevator model of airplane being flown in order to safely accomplish pressure until reaching the appropriate VX attitude to ensure a takeoff at maximum performance. a smooth and firm lift-off, or rotation. Since the airplane accelerates more rapidly after lift-off, the pilot must apply VX is the speed at which the airplane achieves the greatest gain additional back-elevator pressure to hold a constant airspeed. in altitude for a given distance over the ground. It is usually After becoming airborne, the pilot will maintain a wings- slightly less than VY, which is the greatest gain in altitude level climb at VX until all obstacles have been cleared or; if per unit of time. The specific speeds to be used for a given no obstacles are present, until reaching an altitude of at least airplane are stated in the FAA-approved AFM/POH. The 50 feet above the takeoff surface. Thereafter, the pilot may pilot should be aware that, in some airplanes, a deviation of lower the pitch attitude slightly and continue the climb at VY 5 knots from the recommended speed may result in a until reaching a safe maneuvering altitude. The pilot must significant reduction in climb performance; therefore, the always remember that an attempt to pull the airplane off the pilot must maintain precise control of the airspeed to ensure ground prematurely, or to climb too steeply, may cause the the maneuver is executed safely and successfully. airplane to settle back to the runway or make contact with obstacles. Even if the airplane remains airborne, until the pilot reaches VX, the initial climb will remain flat, which Climb at VX Climb at VY Retract gear and flaps Rotate at approximately VX Figure 5-8. Short-field takeoff. 5-10
diminishes the pilot's ability to successfully perform the • Holding the airplane on the ground unnecessarily with climb and/or clear obstacles. [Figure 5-9] excessive forward-elevator pressure. The objective is to rotate to the appropriate pitch attitude at • Inadequate rotation resulting in excessive speed after (or near) VX. The pilot should be aware that some airplanes lift-off. have a natural tendency to lift off well before reaching VX. In these airplanes, it may be necessary to allow the airplane • Inability to attain/maintain VX. to lift-off in ground effect and then reduce pitch attitude to level until the airplane accelerates to VX with the wheels • Fixation on the airspeed indicator during initial climb. just clear of the runway surface. This method is preferable to forcing the airplane to remain on the ground with forward- • Premature retraction of landing gear and/or wing flaps. elevator pressure until VX is attained. Holding the airplane on the ground unnecessarily puts excessive pressure on the Soft/Rough-Field Takeoff and Climb nose-wheel and may result in “wheel barrowing.” It also hinders both acceleration and overall airplane performance. Takeoffs and climbs from soft fields require the use of operational techniques for getting the airplane airborne as Initial Climb quickly as possible to eliminate the drag caused by tall grass, On short-field takeoffs, the landing gear and flaps should soft sand, mud, and snow and may require climbing over an remain in takeoff position until the airplane is clear of obstacle. The technique makes judicious use of ground effect obstacles (or as recommended by the manufacturer) and VY to reduce landing gear drag and requires an understanding has been established. Until all obstacles have been cleared, of the airplane’s slow speed characteristics and responses. the pilot must maintain focus outside the airplane instead of These same techniques are also useful on a rough field where reaching for landing gear or flap controls or looking inside the the pilot should get the airplane off the ground as soon as airplane for any reason. When the airplane is stabilized at VY, possible to avoid damaging the landing gear. the landing gear (if retractable) and flaps should be retracted. It is usually advisable to raise the flaps in increments to avoid Taking off from a soft surface or through soft surfaces or long, sudden loss of lift and settling of the airplane. Next, reduce wet grass reduces the airplane’s ability to accelerate during the power to the normal climb setting or as recommended the takeoff roll and may prevent the airplane from reaching by the airplane manufacturer. adequate takeoff speed if the pilot applies normal takeoff techniques. The pilot must be aware that the correct takeoff Common errors in the performance of short-field takeoffs procedure for soft fields is quite different from the takeoff and maximum performance climbs are: procedures used for short fields with firm, smooth surfaces. To minimize the hazards associated with takeoffs from soft • Failure to review AFM/POH and performance charts or rough fields, the pilot should transfer the support of the prior to takeoff. airplane’s weight as rapidly as possible from the wheels to the wings as the takeoff roll proceeds by establishing and • Failure to adequately clear the area. maintaining a relatively high AOA or nose-high pitch attitude as early as possible. The pilot should lower the wing flaps prior • Failure to utilize all available runway/takeoff area. to starting the takeoff (if recommended by the manufacturer) to provide additional lift and to transfer the airplane’s weight • Failure to have the airplane properly trimmed prior to from the wheels to the wings as early as possible. The pilot takeoff. should maintain a continuous motion with sufficient power while lining up for the takeoff roll as stopping on a soft • Premature lift-off resulting in high drag. surface, such as mud or snow, might bog the airplane down. Effect of Premature Lift-off Premature rotation Airplane may lift off Flight below VX results increases drag, at low airspeed in shallow climb decreases acceleration, Airplane may settle and increases takeoff distance back to the ground Figure 5-9. Effect of premature lift-off. 5-11
Takeoff Roll retracted immediately so that any wet snow or slush to be air-dried. In the event an obstacle must be cleared after a As the airplane is aligned with the takeoff path, the pilot soft-field takeoff, the pilot should perform the climb-out at should apply takeoff power smoothly and as rapidly as the VX until the obstacle has been cleared. The pilot should then powerplant can accept without faltering. As the airplane adjust the pitch attitude to VY and retract the gear and flaps. accelerates, the pilot should apply enough back-elevator The power can then be reduced to the normal climb setting. pressure to establish a positive AOA and to reduce the weight The pilot may then reduce power to normal climb setting. supported by the nose-wheel. When the airplane is held at a nose-high attitude throughout Common errors in the performance of soft/rough field takeoff the takeoff run, the wings increasingly relieve the wheels of and climbs are: the airplane’s weight as speed increases and lift develops, thereby minimizing the drag caused by surface irregularities • Failure to review AFM/POH and performance charts or adhesion. If this attitude is accurately maintained, the prior to takeoff. airplane virtually flies itself off the ground, becoming airborne but at an airspeed slower than a safe climb speed • Failure to adequately clear the area. because of ground effect. [Figure 5-10] • Insufficient back-elevator pressure during initial Lift-Off takeoff roll resulting in inadequate AOA. After the airplane becomes airborne, the pilot should gently lower the nose with the wheels clear of the surface to allow • Failure to cross-check engine instruments for the airplane to accelerate to VY, or VX if obstacles must be indications of proper operation after applying power. cleared. Immediately after the airplane becomes airborne and while it accelerates, the pilot should be aware that, while • Poor directional control. transitioning out of the ground effect area, the airplane will have a tendency to settle back onto the surface. An attempt • Climbing too high after lift-off and not leveling off to climb prematurely or too steeply may cause the airplane low enough to maintain ground effect altitude. to settle back to the surface as a result of the loss of ground effect. During the transition out of the ground effect area, the • Abrupt and/or excessive elevator control while pilot should not attempt to climb out of ground effect before attempting to level off and accelerate after liftoff. reaching the sufficient climb airspeed, as this may result in the airplane being unable to climb further, even with full power • Allowing the airplane to “mush” or settle resulting in applied. Therefore, it is essential that the airplane remain an inadvertent touchdown after lift-off. in ground effect until at least VX is reached. This requires a good understanding of the control pressures, aircraft • Attempting to climb out of ground effect area before responses, visual clues, and acceleration characteristics of attaining sufficient climb speed. that particular airplane. • Failure to anticipate an increase in pitch attitude as Initial Climb the airplane climbs out of ground effect. After a positive rate of climb is established, and the airplane has accelerated to VY, the pilot should retract the landing gear Rejected Takeoff/Engine Failure and flaps, if equipped. If departing from an airstrip with wet snow or slush on the takeoff surface, the gear should not be Emergency or abnormal situations can occur during a takeoff that require a pilot to reject the takeoff while still on the runway. Circumstances such as a malfunctioning powerplant, inadequate acceleration, runway incursion, or air traffic conflict may be reasons for a rejected takeoff. Prior to takeoff, the pilot should identify a point along the runway at which the airplane should be airborne. If that Raise nosewheel Soft-field Takeoff Level off in ground effect Accelerate in ground as soon as possible Lift off effect to VX or VY Accelerate Figure 5-10. Soft-field takeoff. 5-12
point is reached and the airplane is not airborne, immediate At airports that use noise abatement procedures, reminder action should be taken to discontinue the takeoff. Properly signs may be installed at the taxiway hold positions for planned and executed, the airplane can be stopped on the applicable runways to remind pilots to use and comply with remaining runway without using extraordinary measures, noise abatement procedures on departure. Pilots who are not such as excessive braking that may result in loss of directional familiar with these procedures should ask the tower or air control, airplane damage, and/or personal injury. traffic facility for the recommended procedures. In any case, pilots should be considerate of the surrounding community In the event a takeoff is rejected, the power is reduced to idle while operating their airplane to and from such an airport. and maximum braking applied while maintaining directional This includes operating as quietly, and safely as possible. control. If it is necessary to shut down the engine due to a fire, the mixture control should be brought to the idle Chapter Summary cutoff position and the magnetos turned off. In all cases, the manufacturer’s emergency procedure should be followed. The takeoff and initial climb are relatively short phases required for every flight and are often taken for granted, Urgency characterizes all power loss or engine failure yet 1 out of 5 accidents occur during this phase and half the occurrences after lift-off. In most instances, the pilot has only mishaps are the result of pilot error. Becoming proficient in a few seconds after an engine failure to decide what course and applying the techniques and principles discussed in this of action to take and to execute it. chapter help pilots reduce their susceptibility to becoming a mishap statistic. The POH/AFM ground roll distances for In the event of an engine failure on initial climb-out, the take-off and landing added together provide a good estimate pilot’s first responsibility is to maintain aircraft control. At a of the total runway needed to accelerate and then stop. climb pitch attitude without power, the airplane is at or near a stalling AOA. At the same time, the pilot may still be holding right rudder. The pilot must immediately lower the nose to prevent a stall while moving the rudder to ensure coordinated flight. Attempting to turn back to the takeoff runway should not be attempted. The pilot should establish a controlled glide toward a plausible landing area, preferably straight ahead. Noise Abatement Aircraft noise problems are a major concern at many airports throughout the country. Many local communities have pressured airports into developing specific operational procedures that help limit aircraft noise while operating over nearby areas. As a result, noise abatement procedures have been developed for many of these airports that include standardized profiles and procedures to achieve these lower noise goals. Airports that have noise abatement procedures provide information to pilots, operators, air carriers, air traffic facilities, and other special groups that are applicable to their airport. These procedures are available to the aviation community by various means. Most of this information comes from the Chart Supplements, local and regional publications, printed handouts, operator bulletin boards, safety briefings, and local air traffic facilities. 5-13
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GroundChapter6 Reference Maneuvers Introduction Initial pilot training requires that a pilot understand the relationship of the various flight controls pressure inputs to the resulting attitudes of the airplane. This allows a pilot to develop a sense of feel and understand the various indications of airplane performance, such as pitch, roll, and yaw attitudes. With sufficient competency in this environment, the pilot is ready to apply these skills and place the airplane, not only in the correct attitude and power configuration, but also in orientation to specific ground-based references. These skills are the basis for traffic patterns, survey, photographic, sight- seeing, aerial application (crop dusting) and various other flight profiles requiring specific flightpaths referenced to points on the surface. 6-1
A pilot must develop the proper coordination, timing, and references to make almost imperceptible adjustments to the attention to accurately and safely maneuver the airplane with amount of deflection on the steering wheel, as well as the regard to the required attitudes and ground references. Ground pressure on the accelerator pedal to smoothly join the lane reference maneuvers are the principle flight maneuvers that into which they are turning. In the same manner, multiple combine the four fundamentals (straight-and-level, turns, references are required to precisely control the airplane in climbs, and descents) into a set of integrated skills that the reference to the ground. pilot uses in their everyday flight activity. A pilot must develop the skills necessary to accurately control, through the effect Not all ground-based references are visually equal and some and use of the flight controls, the flightpath of the airplane understanding of those differences is important for their in relationship to the ground. From every takeoff to every selection and use. For example, larger objects or references landing, a pilot exercises these skills in controlling the airplane. may appear closer than they actually are when compared to smaller objects or references. Also, prevailing visibility has a The pilot should be introduced by their instructor to ground significant effect on the pilot’s perception of the distance to a reference maneuvers as soon as the pilot shows proficiency reference. Excellent visibilities with clear skies tend to make in the four fundamentals. Accomplishing the ground an object or reference appear closer than when compared reference maneuvers requires that the pilot competently to a hazy day with poor visibility. Another example is that manipulate the flight controls without any undue attention rain can alter the visual image in a manner that an illusion to mechanical flight control inputs—the pilot applies the of being at a higher altitude may be perceived, and brighter necessary flight control pressures to affect the airplane’s objects or references may appear closer than dimmer objects. attitude and position by using the outside natural horizon Being aware of typical visual illusions helps a pilot select the and ground-based references with brief periods of scanning best references for ground reference maneuvers. It is best, the flight instruments. however sometimes impracticable, to find ground-based references that are similar in size and proportion. Maneuvering by Reference to Ground Objects Ground-based references can be numerous. Excellent examples are breakwaters, canals, fence lines, field The purpose of ground reference maneuvers is to train pilots boundaries, highways, railroad tracks, roads, pipe lines, to accurately place the airplane in relationship to specific power lines, water-tanks, and others; however, choices can be references and maintain a desired ground track. Such limited by geography, population density, infrastructure, or precision requires that a pilot simultaneously evaluate the structures. Selecting a ground-based reference requires prior airplane’s attitude, reference points along the desired path, consideration, such as the type of maneuver being performed, and the natural horizon. Vision is the most utilized sense altitude at which the maneuver will be performed, emergency in maneuvering in orientation to ground-based references; landing requirements, density of structures, wind direction, however, all senses are actively involved at different levels. visibility, and the type of airspace. For example, touch provides tactile feedback as to the required flight control pressures to overcome flight control Division of attention is an important skill that a pilot must surface forces that indirectly indicate the airplane’s airspeed develop. A pilot must be able to fly the airplane affecting and aerodynamic load. the flight controls in a manner they will place the airplane in the needed attitude while tracking a specific path over It is a common error for beginning pilots to fixate on a specific the ground. In addition, the pilot must be able to scan for reference, such as a single location on the ground or the hazards such as other aircraft, be immediately prepared for an natural horizon. To be effective, the pilot must scan between emergency landing should the need arise, and scan the flight several visual references to determine relative motion and to and engine instruments at regular intervals to ensure that a determine if the airplane is maintaining, or drifting to or from, pending situation, such as decreasing oil pressure, does not the desired ground track. A pilot fixating on any one reference turn into an unexpected incident. eliminates the ability to determine rate, which significantly degrades a pilot’s performance. Visual scanning across Safety is paramount in all aspects of flying. Awareness and several references allows the pilot to develop the important practice of safety-enhancing procedures must be constantly skill of determining the rate of closure to a specific point. exercised. Ground reference maneuvers place the airplane in Consider a skilled automobile driver in a simple intersection an environment where heightened awareness is needed. Pilots turn; the driver does not merely turn the steering wheel some should be looking for other aircraft, including helicopters, degree and hope that it will work out. The skilled driver radio towers, and assessing locations for emergency picks out several references, such as an island to their side, landings. Pilots should always clear the area with two 90° a painted lane line, or the opposing curb, and they use those 6-2
clearing turns looking to the left and the right, as well as Correcting Drift During Straight-and-Level Flight above and below the airplane. The maneuver area should When flying straight and level and following a selected not cause disturbances and be well away from groups of straight-line direct ground track, the preferred method of people, livestock, or communities. Before performing any correcting for wind drift is to angle the airplane sufficiently maneuver, the pilot should complete the required checklist into the wind to cancel the effect of the sideways drift caused items, make any radio announcements (such as on a practice by the wind. The wind’s speed, the angle between the wind area frequency), and safety clearing turns. As a general note, direction and the airplane’s longitudinal axis, and the airspeed a ground reference maneuver should not exceed a bank angle of the airplane determines the required wind correction angle. of 45° or an airspeed greater than maneuvering speed. As For example, an airplane with an airspeed of 100 knots, a 20 part of preflight planning, the pilot should determine the knot wind at 90° to the airplane’s longitudinal axis, and a 12° predicted (POH/AFM) stall speed at 50° or the highest bank angle into the wind is required to cancel the airplane’s drift. angle planned plus some margin for error in maneuvering If the wind in the above example is only 10 knots, the wind correction angle required to cancel the drift is six degrees. Drift and Ground Track Control When the drift has been neutralized by heading the airplane into the wind, the airplane will fly the direct straight ground track. Wind direction and velocity variations are the primary effects requiring corrections of the flightpath during ground To further illustrate this point, if a boat is crossing a river reference maneuvers. Unlike an automobile, but similar to a and the river’s current is completely still, the boat could head boat or ship, wind directly influences the path that the airplane directly to a point on the opposite shore on a straight course travels in reference to the ground. Whenever the airplane is to that opposite point without any drift; however, rivers tend in flight, the movement of the air directly affects the actual to have a downstream current that must be considered if the ground track of the airplane. captain wants the boat to arrive at the opposite shore using a direct straight path. Any downstream current pushes the For example, an airplane is traveling at 90 knots (90 nautical boat sideways and downstream at the speed of the current. miles per hour) and the wind is blowing from right to left at To counteract this downstream movement, the boat must 10 knots. The airplane continues forward at 90 knots but also move upstream at the same speed as the river is moving the travels left 10 nautical miles for every hour of flight time. If boat downstream. This is accomplished by angling the boat the airplane, in this example doubles its speed to 180 knots, upstream sufficiently to counteract the downstream flow. If it still drifts laterally to the left 10 nautical miles every hour. this is done, the boat follows a direct straight track across The airplane travels within an often moving body of air, so the river to the intended destination point. The amount of traveling to a point on the surface requires compensation for angle required is dependent on the forward speed of the boat the movement of the air mass. and the speed of the current. The slower the forward speed of the boat and/or the faster speed of the current, the greater Ground reference maneuvers are generally flown at altitudes the angle must be to counteract the drift. The converse is between 600 and 1,000 feet above ground level (AGL). also true. [Figure 6-1] The pilot must consider the following when selecting the maneuvering altitude: As soon as an airplane lifts off the surface and levels the wings, if there is any crosswind, the airplane will begin • The lower the maneuvering altitude, the faster the tracking sideways with the wind. Any wind not directly on airplane appears to travel in relation to the ground. the nose or tail of the airplane will drift the airplane sideways at a speed up to the speed of the wind. A wind that is directly • Drift should be easily recognizable from both sides to the right or the left (at a 90° angle) drifts the airplane of the airplane. sideways at the speed of the wind; when the wind is halfway between the side and the nose of the airplane (at a 45° angle), • The altitude should provide obstruction clearance of it drifts the airplane sideways at just over 70 percent of the no less than 500 feet vertically above the obstruction speed of the wind. It should be understood that pilots do and 2,000 feet horizontally. not calculate the required drift correction angles for ground reference maneuvers; they merely use the references and • In case of an engine failure, the pilot must plan, adjust the airplane’s relationship to those references to cancel consider, and be alert for forced landing areas while any drift. The groundspeed of the airplane is also affected understanding that the lower the airplane’s altitude, the less time there is to configure the airplane for an emergency landing and the shorter the glide distance. • Any specific altitude required by test standards. 6-3
Current Current No current, no drift. With a current, the boat drifts With proper correction, the boat downstream unless corrected. stays on intended course. Wind Wind No wind, no drift. With any wind, the airplane drifts With proper correction, the airplane Figure 6-1. Wind drift. downwind unless corrected. stays on intended course. by the wind. As the wind direction becomes parallel to the based constant radius turn. The converse is also true: the airplane’s longitudinal axis, the magnitude of the wind’s slower the groundspeed, the shallower the airplane needs to effect on the groundspeed is greater; as the wind becomes be banked to maintain a ground-based constant radius turn. perpendicular to the longitudinal axis, the magnitude of the wind’s effect on the groundspeed is less. In general, When For a given true airspeed, the radius of turn in the air varies the wind is blowing straight into the nose of the airplane, the proportionally with the bank angle. To maintain the constant groundspeed will be less than the airspeed. When the wind is radius over the ground, the bank angle is proportional to blowing from directly behind the airplane, the groundspeed ground speed. For example, an airplane is in the downwind will be faster than the airspeed. In other words, when the position at 100 knots groundspeed. In this example, the wind is airplane is headed upwind, the groundspeed is decreased; 10 knots, meaning that the airplane is at an airspeed of 90 knots when headed downwind, the groundspeed is increased. (for this discussion, we ignore true, calibrated, and indicate airspeed and assume that they are all the same). If the pilot Constant Radius During Turning Flight starts a downwind turn with a 45° “steepest” bank angle, the In a no-wind condition, the pilot can perform a ground-based turn radius is approximately 890 feet. Let’s assume the airplane constant radius turn by accurately maintaining a constant is now upwind with a groundspeed of 80 knots. In order to bank angle throughout the turn; however, with any wind the maintain the 890-foot radius, the pilot must reduce the bank complexities of maintaining a ground-based constant radius angle to a shallowest bank of approximately 33°. In another turn increase. When wind is present, during ground reference example, if the downwind is flown at an airspeed of 90 knots maneuvers involving turns, the pilot must correct for wind in a 10 knot tailwind with a desired turn radius of 2,000 feet, drift. [Figure 6-2] Throughout the turn, the wind is acting on the “steepest” bank angle needs to be at approximately 24° the airplane from a constantly changing angle—increasing or and the upwind “shallowest” bank angle at approximately 16°. decreasing the groundspeed in a manner similar to straight flight. To follow a circular, constant radius ground track, the To demonstrate the effect that wind has on turns, the pilot bank angle must vary to compensate for wind drift throughout should select a straight-line ground reference, such as a the turn. The airplane’s ground-based turn radius is affected road or railroad track. [Figure 6-3] Choosing a straight-line by the airplane’s groundspeed: the faster the groundspeed, ground reference that is parallel to the wind, the airplane the steeper the airplane must be banked to maintain a ground- would be flown into the wind and directly over the selected 6-4
Actual ground path Intended ground path No wind 20 knot wind Figure 6-2. Effect of wind during a turn. straight-line ground reference. Once a straight-line ground pilot holds a constant bank angle. In both examples, the path reference is established, the pilot makes a 360° constant over the ground is an elongated circle, although in reference medium banked turn. As the airplane completes the 360° to the air, the airplane flew a perfect continuous radius. turn, it should return directly over the straight-line ground reference but downwind from the starting point. Choosing a In order to compensate for the elongated, somewhat circular straight-line ground reference that has a crosswind, and using path over the ground, the pilot must adjust the bank angle the same 360° constant medium-banked turn, demonstrates as the groundspeed changes throughout the turn. Where how the airplane drifts away from the reference even as the groundspeed is the fastest, such as when the airplane is AC No wind Wind B D Wind Wind Figure 6-3. Effect of wind during turn. 6-5
headed downwind, the turn bank angle must be steepest; • Maintaining a specific relationship between the where groundspeed is the slowest, such as when the airplane airplane and the ground. is headed upwind, the turn bank angle must be shallow. It is necessary to increase or decrease the angle of bank, which • Dividing attention between the flightpath, ground- increases or decreases the rate of turn, to achieve the desired based references, manipulating the flight controls, constant radius track over the ground. and scanning for outside hazards and instrument indications. Ground reference maneuvers should always be entered from a downwind position. This allows the pilot to establish the • Adjusting the bank angle during turns to correct for steepest bank angle required to maintain a constant radius groundspeed changes in order to maintain constant ground track. If the bank is too steep, the pilot should radius turns. immediately exit the maneuver and re-establish a lateral position that is further from the ground reference. The pilot • Rolling out from a turn with the required wind should avoid bank angles in excess of 45°due to the increased correction angle to compensate for any drift cause by stalling speed. the wind. Tracking Over and Parallel to a Straight Line • Establishing and correcting the wind correction angle The pilot should first be introduced to ground reference in order to maintain the track over the ground. maneuvers by correcting for the effects of a crosswind over a straight-line ground reference, such as road or railroad tracks. • Preparing the pilot for the airport traffic pattern and If a straight road or railroad track is unavailable, the pilot will subsequent landing pattern practice. choose multiple references (three minimum) which, when an imaginary visual reference line is extended, represents First, a square, rectangular field, or an area with suitable a straight line. The reference should be suitably long so the ground references on all four sides, as previously mentioned pilot has sufficient time to understand the concepts of wind should be selected consistent with safe practices. The correction and practice the maneuver. Initially, the maneuver airplane should be flown parallel to and at an equal distance should be flown directly over the ground reference with the between one-half to three-fourths of a mile away from pilot angling the airplane’s longitudinal axis into the wind the field boundaries or selected ground references. The sufficiently such as to cancel the effect of drift. The pilot flightpath should be positioned outside the field boundaries should scan between far ahead and close to the airplane to or selected ground references so that the references may be practice tracking multiple references. easily observed from either pilot seat. It is not practicable to fly directly above the field boundaries or selected When proficiency has been demonstrated by flying directly ground references. The pilot should avoid flying close to over the ground reference line, the pilot should then practice the references, as this will require the pilot to turn using flying a straight parallel path that is offset from the ground very steep bank angles, thereby increasing aerodynamic reference. The offset parallel path should not be more than load factor and the airplane’s stall speed, especially in the three-fourths of a mile from the reference line. The maneuver downwind to crosswind turn. should be flown offset from the ground references with the pilot angling the airplane’s longitudinal axis into the wind The entry into the maneuver should be accomplished sufficiently to cancel the effect of drift while maintaining a downwind. This places the wind on the tail of the airplane parallel track. and results in an increased groundspeed. There should be no wind correction angle if the wind is directly on the tail of Rectangular Course the airplane; however, a real-world situation results in some drift correction. The turn from the downwind leg onto the A principle ground reference maneuver is the rectangular base leg is entered with a relatively steep bank angle. The course. [Figure 6-4] The rectangular course is a training pilot should roll the airplane into a steep bank with rapid, but maneuver in which the airplane maintains an equal distance not excessive, coordinated aileron and rudder pressures. As from all sides of the selected rectangular references. The the airplane turns onto the following base leg, the tailwind maneuver is accomplished to replicate the airport traffic lessens and becomes a crosswind; the bank angle is reduced pattern that an airplane typically maneuvers while landing. gradually with coordinated aileron and rudder pressures. The While performing the rectangular course maneuver, the pilot pilot should be prepared for the lateral drift and compensate should maintain a constant altitude, airspeed, and distance by turning more than 90° angling toward the inside of the from the ground references. The maneuver assists the pilot rectangular course. in practicing the following: The next leg is where the airplane turns from a base leg position to the upwind leg. Ideally, the wind is directly on 6-6
Exit Downwind Enter 45° to downwind Turn more than Complete turn at boundary 90° rollout with wind correction Turn more than 90° established Start turn at boundary No wind correction Base Track with no wind correction Complete turn at boundary Wind Track with no wind correction Start turn Turn into wind at boundary Start turn Crosswind at boundary Turn into wind Complete turn at boundary Turn less than 90° rollout with wind correction established Turn less than 90° Upwind No wind correction Start turn at boundary Complete turn at boundary Figure 6-4. Rectangular course. the nose of the airplane resulting in a direct headwind and The final turn is back to the downwind leg, which requires decreased groundspeed; however, a real-world situation a medium-banked angle and a turn greater than 90°. The results in some drift correction. The pilot should roll the groundspeed will be increasing as the turn progresses and airplane into a medium banked turn with coordinated aileron the bank should be held and then rolled out in a rapid, but and rudder pressures. As the airplane turns onto the upwind not excessive, manner using coordinated aileron and rudder leg, the crosswind lessens and becomes a headwind, and the pressures. bank angle is gradually reduced with coordinated aileron and rudder pressures. Because the pilot was angled into the wind For the maneuver to be executed properly, the pilot must on the base leg, the turn to the upwind leg is less than 90°. visually utilize the ground-based, nose, and wingtip references to properly position the airplane in attitude and The next leg is where the airplane turns from an upwind leg in orientation to the rectangular course. Each turn, in order position to the crosswind leg. The pilot should slowly roll to maintain a constant ground-based radius, requires the the airplane into a shallow-banked turn, as the developing bank angle to be adjusted to compensate for the changing crosswind drifts the airplane into the inside of the rectangular groundspeed—the higher the groundspeed, the steeper the course with coordinated aileron and rudder pressures. As the bank. If the groundspeed is initially higher and then decreases airplane turns onto the crosswind leg, the headwind lessens throughout the turn, the bank angle should progressively and becomes a crosswind. As the turn nears completion, the decrease throughout the turn. The converse is also true, bank angle is reduced with coordinated aileron and rudder if the groundspeed is initially slower and then increases pressures. To compensate for the crosswind, the pilot must throughout the turn, the bank angle should progressively angle into the wind, toward the outside of the rectangular increase throughout the turn until rollout is started. Also, course, which requires the turn to be less than 90°. the rate for rolling in and out of the turn should be adjusted 6-7
to prevent drifting in or out of the course. When the wind is Turns Around a Point from a direction that could drift the airplane into the course, the banking roll rate should be slow. When the wind is from Turns around a point are a logical extension of both the a direction that could drift the airplane to the outside of the rectangular course and S-turns across a road. The maneuver course, the banking roll rate should be quick. is a 360° constant radius turn around a single ground- based reference point. [Figure 6-5] The principles are the The following are the most common errors made while same in any turning ground reference maneuver— higher performing rectangular courses: groundspeeds require steeper banks and slower ground speeds require shallower banks. The objectives of turns around a • Failure to adequately clear the area above, below, point are as follows: and on either side of the airplane for safety hazards, initially and throughout the maneuver. • Maintaining a specific relationship between the airplane and the ground. • Failure to establish a constant, level altitude prior to entering the maneuver. • Dividing attention between the flightpath, ground- based references, manipulating of the flight controls, • Failure to maintain altitude during the maneuver. and scanning for outside hazards and instrument indications. • Failure to properly assess wind direction. • Adjusting the bank angle during turns to correct for • Failure to establish the appropriate wind correction groundspeed changes in order to maintain a constant angle. radius turn; steeper bank angles for higher ground speeds, shallow bank angles for slower groundspeeds. • Failure to apply coordinated aileron and rudder pressure, resulting in slips and skids. • Improving competency in managing the quickly changing bank angles. • Failure to manipulate the flight controls in a smooth and continuous manner. • Establishing and adjusting the wind correction angle in order to maintain the track over the ground. • Failure to properly divide attention between controlling the airplane and maintaining proper orientation with • Developing the ability to compensate for drift in the ground references. quickly changing orientations. • Failure to execute turns with accurate timing. • Developing further awareness that the radius of a turn is correlated to the bank angle. Wind Steeper bank Upwind half of circle Shallowest bank Steepest bank Figure 6-5. Turns around a point. Downwind half of circle 6-8 Shallower bank
To perform a turn around a point, the pilot must complete Upon entering the maneuver, depending on the wind’s speed, at least one 360° turn; however, to properly assess wind it may be necessary to roll into the initial bank at a rapid rate direction, velocity, bank required, and other factors related so that the steepest bank is set quickly to prevent the airplane to turns in wind, the pilot should complete two or more from drifting outside of the desired turn radius. This is best turns. As in other ground reference maneuvers, when wind is accomplished by repeated practice and assessing the required present, the pilot must a constantly adjust the airplane’s bank roll in rate. Thereafter, the pilot should gradually decrease the and wind correction angle to maintain a constant radius turn angle of bank until the airplane is headed directly upwind. around a point. In contrast to the ground reference maneuvers As the upwind becomes a crosswind and then a downwind, discussed previously in which turns were approximately the pilot should gradually steepen the bank to the steepest limited to either 90° or 180°, turns around a point are angle upon reaching the initial point of entry. consecutive 360° turns where, throughout the maneuver, the pilot must constantly adjust the bank angle and the resulting During the downwind half of the turn, the pilot should rate of turn in proportion to the groundspeed as the airplane progressively adjust the airplane’s heading toward the sequences through the various wind directions. The pilot inside of the turn. During the upwind half, the pilot should should make these adjustments by applying coordinated progressively adjust the airplane’s heading toward the aileron and rudder pressure throughout the turn. outside of the turn. Recall from the previous discussion on wind correction angle that the airplane’s heading should be When performing a turn around a point, the pilot should ahead of its position over the ground during the downwind select a prominent, ground-based reference that is easily half of the turn behind its position during the upwind half. distinguishable yet small enough to present a precise Remember that the goal is to make a constant radius turn reference. [Figure 6-6] The pilot should enter the maneuver over the ground and, because the airplane is flying through downwind, where the groundspeed is at its fastest, at the a moving air mass, the pilot must constantly adjust the bank appropriate radius of turn and distance from the selected angle to achieve this goal. ground-based reference point. In a high-wing airplane, the lowered wing may block the view of the ground reference The following are the most common errors in the performance point, especially in airplanes with side-by-side seating during of turns around a point: a left turn (assuming that the pilot is flying from the left seat). To prevent this, the pilot may need to change the maneuvering • Failure to adequately clear the area above, below, altitude or the desired turn radius. The pilot should ensure and on either side of the airplane for safety hazards, that the reference point is visible at all times throughout the initially and throughout the maneuver. maneuver, even with the wing lowered in a bank. Moderate bank Steepest bank 1 Shallowest bank 2 Entry 5 Wings level 6-9 3 Steepest bank 4 Shallowest bank Moderate bank Wind Figure 6-6. S-turns.
• Failure to establish a constant, level altitude prior to angle for drift effects and changes in groundspeed, again re- entering the maneuver. crossing the straight-line ground reference as the second 180° constant radius turn is completed. If the straight-line ground • Failure to maintain altitude during the maneuver. reference is of sufficient length, the pilot may complete as many as can be safely accomplished. • Failure to properly assess wind direction. In the same manner as the rectangular course, it is standard • Failure to properly execute constant radius turns. practice to enter ground-based maneuvers downwind where groundspeed is greatest. As such, the roll into the turn must • Failure to manipulate the flight controls in a smooth be rapid, but not aggressive, and the angle of bank must be and continuous manner. steepest when initiating the turn. As the turn progresses, the bank angle and the rate of rollout must be decreased as • Failure to establish the appropriate wind correction the groundspeed decreases to ensure that the turn’s radius angle. is constant. During the first turn, when the airplane is at the 90° point, it will be directly crosswind. In addition to the rate • Failure to apply coordinated aileron and rudder of rollout and bank angle, the pilot must control the wind pressure, resulting in slips or skids. correction angle throughout the turn. S-Turns Controlling the wind correction angle during a turn can be complex to understand. The concept is best understood by S-turns is a ground reference maneuver in which the comprehending the difference between the number of degrees airplane’s ground track resembles two opposite but equal that the airplane has turned over the ground verses the number half-circles on each side of a selected ground-based straight- of degrees that the airplane has turned in the air. For example, line reference. [Figure 6-6] This ground reference maneuver if the airplane is exactly crosswind, meaning directly at a presents a practical application for the correction of wind point that is 90° to the straight-lined ground reference. If the during a turn. The objectives of S-turns across a road are wind, in this example, requires a 10° wind correction angle as follows: (for this example, this is a left turn with the crosswind from the left) the airplane would be at a heading that is 10° ahead • Maintaining a specific relationship between the when directly over the 90° ground reference point. In other airplane and the ground. words, the first 90° track over the ground would result in a heading change of 100° and the last 90° track over the ground • Dividing attention between the flightpath, ground- would result in 80° of heading change. based references, manipulating the flight controls, and scanning for outside hazards and instrument As the turn progresses from a downwind position to an indications. upwind position, the pilot must gradually decrease the bank angle with coordinated aileron and rudder pressure. The pilot • Adjusting the bank angle during turns to correct for should reference the airplane’s nose, wingtips, and the ground groundspeed changes in order to maintain a constant references and adjust the rollout timing so that the airplane radius turn—steeper bank angles for higher ground crosses the straight-line ground reference with the wings speeds, shallow bank angles for slower groundspeeds. level, and at the proper heading, altitude, and airspeed. As the airplane re-crosses the straight-lined ground reference, • Rolling out from a turn with the required wind the pilot should immediately begin the opposite turn—there correction angle to compensate for any drift cause by should be no delay in rolling out from one turn and rolling the wind. into the next turn. Because the airplane is now upwind, the roll in should be smooth and gentle and the initial bank angle • Establishing and correcting the wind correction angle should be shallow. As the turn progresses, the wind changes in order to maintain the track over the ground. from upwind, to crosswind, to downwind. In a similar manner described above, the pilot should adjust the bank angle to • Developing the ability to compensate for drift in correct for changes in groundspeed. As the groundspeed quickly changing orientations. increases, the pilot should increase the bank angle to maintain a constant radius turn. At the 90° crosswind position, the • Arriving at specific points on required headings. airplane should also have the correct wind correction angle. As the airplane turns downwind, the groundspeed increases; With the airplane in the downwind position, the maneuver consists of crossing a straight-line ground reference at a 90° angle and immediately beginning a 180° constant radius turn. The pilot will then adjust the roll rate and bank angle for drift effects and changes in groundspeed, and re-cross the straight-line ground reference in the opposite direction just as the first 180° constant radius turn is completed. The pilot will then immediately begin a second 180° constant radius turn in the opposite direction, adjusting the roll rate and bank 6-10
the bank angle should be increased so that the rate of turn is • Developing the pilot’s skills to visualize each specific used to maintain a constant radius turn. segment of the maneuver and the maneuver as a whole, prior to execution. The following are the most common errors made while performing S-turns across a road: • Developing a pilot’s ability to intuitively manipulate flight controls to adjust the bank angle during turns to • Failure to adequately clear the area above, below, correct for groundspeed changes in order to maintain and on either side of the airplane for safety hazards, constant radius turns and proper ground track between initially and throughout the maneuver. ground references. • Failure to establish a constant, level altitude prior to Eights Along a Road entering the maneuver. Eights along a road is a ground reference maneuver in which the ground track consists of two opposite 360° adjacent turns • Failure to maintain altitude during the maneuver. with the center of each 360° turn and the adjacent turn point perpendicular or parallel to the straight-line ground reference • Failure to properly assess wind direction. (road, railroad tracks, fence line, pipeline right-of-way, etc.). [Figure 6-7] Like the other ground reference maneuvers, its • Failure to properly execute constant radius turns. objective is to further develop division of attention while compensating for drift, maintaining orientation with ground • Failure to manipulate the flight controls in a smooth references, and maintaining a constant altitude. and continuous manner when transitioning into turns. Although eights along a road may be performed with the • Failure to establish the appropriate wind correction wind blowing parallel or perpendicular to the straight-line angle. ground reference, only the perpendicular wind situation is explained since the principles involved are common to each. • Failure to apply coordinated aileron and rudder The pilot should select a straight-line ground reference that is pressure, resulting in slips or skids. perpendicular to the wind and position the airplane parallel to and directly above the straight-line ground reference. Elementary Eights Since this places the airplane in a crosswind position, the pilot must compensate for the wind drift with an appropriate Elementary eights are a family of maneuvers in which each wind correction angle. individual maneuver is one that the airplane tracks a path over the ground similar to the shape of a figure eight. There are The following description is illustrated in Figure 6-7. The various types of eights, progressing from the elementary types airplane is initially in a crosswind position, perpendicular to to very difficult types in the advanced maneuvers. Each eight the wind, and over the ground-based reference. The first turn is intended to develop a pilot’s flight control coordination should be a left turn toward a downwind position starting skills, strengthen their awareness relative to the selected with a steeping bank. When the entry is made into the turn, it ground references, and enhance division of attention so that requires that the turn begin with a medium bank and gradually flying becomes more instinctive than mechanical. Eights steepen to its maximum bank angle when the airplane is require a greater degree of focused attention to the selected directly downwind. As the airplane turns from downwind ground references; however, the real significance of eights to crosswind, the bank angle needs to be gradually reduced is that pilot must strive for flight precision. since groundspeed is decreasing; however, the groundspeed only decreases by 1⁄2 of its velocity during the first 2⁄3 of the Elementary eights include eights along a road, eights across a turn from downwind to crosswind. road, and eights around pylons. Each of these maneuvers is a variation of a turn around a point. Each eight uses two ground The pilot must control the bank angle as well as the rate at reference points about which the airplane turns first in one which the bank angle is reduced so that the wind correction direction and then the opposite direction—like a figure eight. angle is correct. Assuming that the wind is coming from the right side of the airplane, the airplane heading should Eights maneuvers are designed for the following purposes: be slightly ahead of its position over the ground. When the airplane completes the first 180° of ground track, it is directly • Further development of the pilot’s skill in maintaining crosswind, and the airplane should be at the maximum wind a specific relationship between the airplane and the correction angle. ground references. • Improving the pilot’s ability to divide attention between the flightpath and ground-based references, manipulation of the flight controls, and scanning for outside hazards and instrument indications during both turning and straight-line flight. 6-11
Steeper bank WIND Level with crab into wind Shallowest bank Shallowest bank Steepest bank Shallower bank Figure 6-7. Eights along a road. As the turn is continued toward the upwind, the airplane’s pilot should roll the airplane into a medium bank turn in the groundspeed is decreasing, which requires the pilot to reduce opposite direction to begin the 360° turn on the upwind side the bank angle to slow the rate of turn. If the pilot does not of the ground reference. The wind will decrease the airplane’s reduce the bank angle, the continued high rate of turn would groundspeed and drift the airplane back toward the ground cause the turn to be completed prematurely. Another way reference; therefore, the pilot must decrease the bank slowly to explain this effect is—the wind is drifting the airplane during the first 90° of the upwind turn in order to establish a downwind at the same time its groundspeed is slowing; if constant radius. During the next 90° of turn, the pilot should the airplane has a steeper than required bank angle, its rate increase the bank angle, since the groundspeed is increasing, of turn will be too fast and the airplane will complete the to maintain a constant radius and establish the proper wind turn before it has had time to return to the ground reference. correction angle before reaching the 180° upwind position. When the airplane is directly upwind, which is at 270° into As the remaining 180° of turn continues, the wind becomes the first turn, the bank angle should be shallow with no wind correction. As the airplane turns crosswind again, the a tailwind and then a crosswind. Consistent with previous airplane’s groundspeed begins increasing; therefore, the pilot should adjust the bank angle and corresponding rate of turn downwind and crosswind descriptions, the pilot must increase proportionately in order to reach the ground reference at the completion of the 360° ground track. The pilot may vary the bank angle as the airplane reaches the downwind position the bank angle to correct for any previous errors made in judging the returning rate and closure rate. The pilot should and decrease the bank angle as the airplane reaches the time the rollout so that the airplane is straight-and-level over the starting point with enough drift correction to hold it over crosswind position. Further, the rate of roll in and roll out the straight-line ground reference. Assuming that the wind is now from the left, the airplane should be banked at a left should be consistent with how fast the groundspeed changes wind correction angle. during the turn. Remember, when turning from an upwind or After momentarily flying straight-and-level with the established wind correction, along the ground reference, the downwind position to a crosswind position, the groundspeed changes by 1⁄2 during the first 2⁄3 of the 90° turn. The final 1⁄2 of the groundspeed changes in the last 1⁄3 of the turn. In contrast, when turning from a crosswind position to an upwind or downwind position, the groundspeed changes by 1⁄2 during the first 1⁄3 of the 90° turn. The final 1⁄2 of the groundspeed changes in the last 2⁄3 of the turn. 6-12
To successfully perform eights along a ground reference, The pattern involves flying downwind between the pylons the pilot must be able to smoothly and accurately coordinate and upwind outside of the pylons. It may include a short changes in bank angle to maintain a constant radius turn and period of straight-and-level flight while proceeding counteract drift. The speed in which the pilot can anticipate diagonally from one pylon to the other. The pylons should these corrections directly affects the accuracy of the overall be on a line perpendicular to the wind. The maneuver should maneuver and the amount of attention that can be directed be started with the airplane on a downwind heading when toward scanning for outside hazards and instrument indications. passing equally between the pylons. The distance between the pylons and the wind velocity determines the initial angle Eights Across A Road of bank required to maintain a constant turn radius from the This maneuver is a variation of eights along a road and pylons during each turn. The steepest banks are necessary just involves the same principles and techniques. The primary after each turn entry and just before the rollout from each turn difference is that at the completion of each loop of the figure where the airplane is headed downwind and the groundspeed eight, the airplane should cross an intersection of a specific is highest; the shallowest banks are when the airplane is ground reference point. [Figure 6-8] headed directly upwind and the groundspeed is lowest. The loops should be across the road and the wind should be As in other ground reference maneuvers, the rate at which perpendicular to the loops. Each time the reference is crossed, the bank angle must change depends on the wind velocity. If the crossing angle should be the same, and the wings of the the airplane proceeds diagonally from one turn to the other, airplane should be level. The eights may also be performed the rollout from each turn must be completed on the proper by rolling from one bank immediately to the other, directly heading with sufficient wind correction angle to ensure that over the reference. after brief straight-and-level flight, the airplane arrives at the point where a turn of the same radius can be made around Eights Around Pylons the other pylon. The straight-and-level flight segments must Eights around pylons is a ground-reference maneuver with be tangent to both circular patterns. the same principles and techniques of correcting for wind drift as used in turns around a point and the same objectives as Common errors in the performance of elementary eights are: other ground track maneuvers. Eights around pylons utilizes two ground reference points called “pylons.” Turns around • Failure to adequately clear the area above, below, each pylon are made in opposite directions to follow a ground and on either side of the airplane for safety hazards, track in the form of a figure 8. [Figure 6-9] initially and throughout the maneuver. • Poor selection of ground references. Wind Steeping bank Steeper bank Shallowest bank Shallowest bank Shallower bank Steepest bank Steepest bank Shallower bank Figure 6-8. Eights across a road. 6-13
Wind Steeper bank Steepest bank Steeper bank Shallowest bank Shallowest bank Steepest bank Shallower bank Shallower bank Figure 6-9. Eights around pylons. • Failure to establish a constant, level altitude prior to intuitive control of the airplane. Similar to eights around entering the maneuver. pylons except altitude is varied to maintain a specific visual reference to the pivot points. • Failure to maintain adequate altitude control during the maneuver. The goal of the eights-on-pylons is to have an imaginary line that extends from the pilot’s eyes to the pylon. This line must • Failure to properly assess wind direction. be imagined to always be parallel to the airplane’s lateral axis. Along this line, the airplane appears to pivot as it turns around • Failure to properly execute constant radius turns. the pylon. In other words, if a taut string extended from the airplane to the pylon, the string would remain parallel to lateral • Failure to manipulate the flight controls in a smooth axis as the airplane turned around the pylon. At no time should and continuous manner. the string be at an angle to the lateral axis. [Figure 6-10] In explaining the performance of eights-on-pylons, the term • Failure to establish the appropriate wind correction “wingtip” is frequently considered as being synonymous angles. with the proper visual reference line or pivot point on the airplane. This interpretation is not always correct. High-wing, • Failure to apply coordinated aileron and rudder low-wing, sweptwing, and tapered wing airplanes, as well as pressure, resulting in slips or skids. those with tandem or side-by-side seating, all present different angles from the pilot’s eye to the wingtip. [Figure 6-11] • Failure to maintain orientation as the maneuver progresses. Eights-on-Pylons The eights-on-pylons is the most advanced and difficult of the ground reference maneuvers. Because of the techniques involved, the eights-on-pylons are unmatched for developing 6-14
Wind Entry Gaining altitude Gaining altitude Lowest groundspeed, lowest pivotal altitude High groundspeed, high pivotal altitude Figure 6-10. Eights on pylons. The visual reference line, while not necessarily on the wingtip performance of eights-on-pylons, as in other maneuvers itself, may be positioned in relation to the wingtip (ahead, requiring a lateral reference, the pilot should use a visual behind, above, or below), and differs for each pilot and from reference line that, from eye level, parallels the lateral axis each seat in the airplane. This is especially true in tandem of the airplane. (fore and aft) seat airplanes. In side-by-side type airplanes, there is very little variation in the visual reference lines for The altitude that is appropriate for eights-on-pylons is called different persons, if those persons are seated with their eyes the “pivotal altitude” and is determined by the airplane’s at approximately the same level. Therefore, in the correct groundspeed. In previous ground-track maneuvers, the Lateral axis Too high, pylon ahead Line of sight Too low, pylon behind Line of sight Lateral axis Figure 6-11. Line of sight. 6-15
airplane flies a prescribed path over the ground and the pilot pilot continues the descent below the pivotal altitude, the attempts to maintain the track by correcting for the wind. projected visual reference line with respect to the pylon will With eights-on-pylons, the pilot maintains lateral orientation begin to move forward. to a specific spot on the ground. This develops the pilot’s ability to maneuver the airplane accurately while dividing The altitude at which the visual reference line ceases to attention between the flightpath and the selected pylons on move across the ground is the pivotal altitude. If the airplane the ground. descends below the pivotal altitude, the pilot should increase power to maintain airspeed while regaining altitude to the An explanation of the pivotal altitude is also essential. First, point at which the projected reference line moves neither a good rule of thumb for estimating the pivotal altitude is to backward nor forward but actually pivots on the pylon. In this square the groundspeed, then divide by 15 (if the groundspeed way, the pilot can determine the pivotal altitude of the airplane. is in miles per hour) or divide by 11.3 (if the groundspeed is in knots), and then add the mean sea level (MSL) altitude of The pivotal altitude is critical and changes with variations the ground reference. The pivotal altitude is the altitude at in groundspeed. Since the headings throughout turns which, for a given groundspeed, the projection of the visual continuously vary from downwind to upwind, the groundspeed reference line to the pylon appears to pivot. [Figure 6-12] The constantly changes. This results in the proper pivotal altitude pivotal altitude does not vary with the angle of bank unless varying slightly throughout the turn. The pilot should adjust the bank is steep enough to affect the groundspeed. for this by climbing or descending, as necessary, to hold the visual reference line on the pylons. This change in altitude Distance from the pylon affects the angle of bank. At any is dependent on the groundspeed. altitude above that pivotal altitude, the projected reference line appears to move rearward in a circular path in relation to Selecting proper pylon is an important factor of successfully the pylon. Conversely, when the airplane is below the pivotal performing eights-on-pylons. They should be sufficiently altitude, the projected reference line appears to move forward prominent so the pilot can view them when completing the in a circular path. [Figure 6-13] To demonstrate this, the pilot turn around one pylon and heading for the next. They should will fly at maneuvering speed and at an altitude below the also be adequately spaced to provide time for planning the pivotal altitude, and then placed in a medium-banked turn. turns but not spaced so far apart that they cause unnecessary The projected visual reference line appears to move forward straight-and-level flight between the pylons. The selected along the ground (pylon moves back) as the airplane turns. pylons should also be at the same elevation, since differences The pilot then executes a climb to an altitude well above the of over few feet necessitate climbing or descending between pivotal altitude. When the airplane is again at maneuvering each turn. The pilot should select two pylons along a line that speed, it is placed in a medium-banked turn. At the higher lies perpendicular to the direction of the wind. The distance altitude, the projected visual reference line appears to move between the pylons should allow for the straight-and-level backward across the ground (pylon moves forward). flight segment to last from 3 to 5 seconds. After demonstrating the maneuver at a high altitude, the pilot The pilot should estimate the pivotal altitude during preflight should reduce power and begin a descent at maneuvering planning. Weather reports and consultation with other pilots speed in a continuing medium bank turn around the pylon. flying in the area may provide both the wind direction and The apparent backward movement of the projected visual velocity. If the references are previously known (many reference line with respect to the pylon will slow down as flight instructors already have these ground-based reference altitude is lost and will eventually stop for an instant. If the selected), the sectional chart will provide the MSL of the references, the Pilot’s Operating Handbook (POH) provides Groundspeed Approximate the range of maneuvering airspeeds (based on weight), and Pivotal Altitude the wind direction and velocity can be estimated to calculate Knots MPH the appropriate pivotal altitudes. The pilot should calculate 87 100 670 the pivotal altitude for each position: upwind, downwind, 91 105 735 and crosswind. 96 110 810 100 115 885 The pilot should begin the eight-on-pylons maneuver by 104 120 960 flying diagonally crosswind between the pylons to a point 109 125 1050 downwind from the first pylon so that the first turn can be 113 130 1130 made into the wind. As the airplane approaches a position where the pylon appears to be just ahead of the wingtip, the Figure 6-12. Speed versus pivotal altitude. 6-16
Too high Pivotal altitude Too low Figure 6-13. Effect of different altitudes on pivotal altitude. pilot should begin the turn by lowering the upwind wing so that the airplane arrives at a point downwind from the to the point where the visual reference line aligns with the second pylon that is equal in distance from the pylon as the pylon. The reference line should appear to pivot on the pylon. corresponding point was from the first pylon at the beginning As the airplane heads upwind, the groundspeed decreases, of the maneuver. which lowers the pivotal altitude. As a result, the pilot must descend to hold the visual reference line on the pylon. As At this point, the pilot should begin a turn in the opposite the turn progresses on the upwind side of the pylon, the wind direction by lowering the upwind wing to the point where the becomes more of a crosswind. Since this maneuver does not visual reference line aligns with the pylon. The pilot should require the turn to be completed at a constant radius, the pilot then continue the turn the same way the corresponding turn was does not need to apply drift correction to complete the turn. performed around the first pylon but in the opposite direction. If the visual reference line appears to move ahead of the With prompt correction, and a very fine control pressures, pylon, the pilot should increase altitude. If the visual reference it is possible to hold the visual reference line directly on the line appears to move behind the pylon, the pilot should pylon even in strong winds. The pilot may make corrections decrease altitude. Deflecting the rudder to yaw the airplane for temporary variations, such as those caused by gusts and force the wing and reference line forward or backward to or inattention by reducing the bank angle slightly to fly the pylon places the airplane in uncoordinated flight, at low relatively straight to bring forward a lagging visual reference altitude, with steep bank angles and must not be attempted. line or by increasing the bank angle temporarily to turn back a visual reference line that has moved ahead. With practice, As the airplane turns toward a downwind heading, the pilot these corrections may become slight enough to be barely should rollout from the turn to allow the airplane to proceed noticeable. It is important to understand that variations in diagonally to a point tangent on the downwind side of the pylon position are according to the apparent movement of the second pylon. The pilot should complete the rollout with visual reference line. Attempting to correct pivotal altitude the proper wind correction angle to correct for wind drift, by the use of the altimeter is ineffective. 6-17
Eights-on-pylons are performed at bank angles ranging from • Failure to properly execute constant radius turns. shallow to steep. [Figure 6-14] The pilot should understand that the bank chosen does not alter the pivotal altitude. As • Failure to manipulate the flight controls in a smooth proficiency is gained, the instructor should increase the and continuous manner. complexity of the maneuver by directing the student to enter at a distance from the pylon that results in a specific bank • Failure to establish the appropriate wind correction angle at the steepest point in the pylon turn. angles. The most common error in attempting to hold a pylon is • Failure to apply coordinated aileron and rudder incorrect use of the rudder. When the projection of the visual pressure, resulting in slips or skids. reference line moves forward with respect to the pylon, many pilots tend to apply inside rudder pressure to yaw the wing • Failure to maintain orientation as the maneuver backward. When the reference line moves behind the pylon, progresses. they tend to apply outside rudder pressure to yaw the wing forward. The pilot should use the rudder only for coordination. Chapter Summary Other common errors in the performance of eights-on- At the completion of ground reference maneuvers, the pilot pylons are: should not only be able to command the airplane to specific pitch, roll, and yaw attitudes but, while correcting for the • Failure to adequately clear the area above, below, effects of wind drift, also control the airplane’s orientation in and on either side of the airplane for safety hazards, relation to ground-based references. It should be reinforced initially and throughout the maneuver. that safety is paramount in all aspects of flying. Ground reference maneuvers require planning and high levels of • Poor selection of ground references. vigilance to ensure that the practice and performance of these maneuvers are executed where the safety to groups of people, • Failure to establish a constant, level altitude prior to livestock, communities, and the pilot is not compromised. entering the maneuver. To master ground reference maneuvers, a pilot must develop coordination, timing, and division of attention to accurately • Failure to maintain adequate altitude control during maneuver the airplane in reference to flight attitudes and the maneuver. specific ground references. With these enhanced skills, the pilot significantly strengthens their competency in everyday • Failure to properly assess wind direction. flight maneuvers, such as straight-and-level, turns, climbs, and descents. 60° 45° 30° Pivotal altitude Figure 6-14. Bank angle versus pivotal altitude. 6-18
AirportChapter7 Traffic Patterns Introduction Airport traffic patterns are developed to ensure that air traffic is flown into and out of an airport safely. Each airport traffic pattern is established based on the local conditions, including the direction and placement of the pattern, the altitude at which it is to be flown, and the procedures for entering and exiting the pattern. It is imperative that pilots are taught correct traffic pattern procedures and exercise constant vigilance in the vicinity of airports when entering and exiting the traffic pattern. Information regarding the procedures for a specific airport can be found in the Chart Supplements. Additional information on airport operations and traffic patterns can be found in the Aeronautical Information Manual (AIM). 7-1
Airport Traffic Patterns and Operations A pilot is not expected to have extensive knowledge of all traffic patterns at all airports, but if the pilot is familiar Just as roads and streets are essential for operating with the basic rectangular pattern, it is easy to make proper automobiles, airports or airstrips are essential for operating approaches and departures from most airports, regardless airplanes. Every flight begins and ends at an airport or other of whether or not they have control towers. At airports with suitable landing field; therefore, it is essential that pilots learn operating control towers, the tower operator can instruct the traffic rules, traffic procedures, and traffic pattern layouts pilots to enter the traffic pattern at any point or to make a that may be in use at various airports. straight-in approach without flying the usual rectangular pattern. Many other deviations are possible if the tower When an automobile is driven on congested city streets, it operator and the pilot work together in an effort to keep traffic can be brought to a stop to give way to conflicting traffic; moving smoothly. Jets or heavy airplanes will frequently however, an airplane can only speed up, climb, descend, and be fly wider and/or higher patterns than lighter airplanes, and slowed down. Consequently, traffic patterns and traffic control in many cases, will make a straight-in approach for landing. procedures have been established for use at airports. Traffic patterns provide procedures for takeoffs, departures, arrivals, Compliance with the basic rectangular traffic pattern reduces and landings. The exact nature of each airport traffic pattern the possibility of conflicts at airports without an operating is dependent on the runway in use, wind conditions (which control tower. It is imperative that a pilot form the habit of determine the runway in use), obstructions, and other factors. exercising constant vigilance in the vicinity of airports even when the air traffic appears to be light. Midair collisions Control towers and radar facilities provide a means of usually occur on clear days with unlimited visibility. Never adjusting the flow of arriving and departing aircraft and assume you have found all of the air traffic and stop scanning. render assistance to pilots in busy terminal areas. Airport lighting and runway marking systems are used frequently to Figure 7-1 shows a standard rectangular traffic pattern. alert pilots to abnormal conditions and hazards so arrivals The traffic pattern altitude is usually 1,000 feet above the and departures can be made safely. elevation of the airport surface. The use of a common altitude at a given airport is the key factor in minimizing the risk of Airports vary in complexity from small grass or sod strips collisions at airports without operating control towers. to major terminals with paved runways and taxiways. Regardless of the type of airport, a pilot must know and abide When operating in the traffic pattern at an airport without an by the rules and general operating procedures applicable to operating control tower, the pilot should maintain an airspeed the airport being used. The objective is to keep air traffic of no more than 200 knots (230 miles per hour (mph)) as moving with maximum safety and efficiency. Information required by Title 14 of the Code of Federal Regulations (14 on traffic patterns and operating procedures for an airport CFR) part 91. In any case, the pilot should adjust the airspeed, is documented in the Chart Supplements, as well as visual when necessary, so that it is compatible with the airspeed of markings on the airport itself. The use of any traffic the other airplanes in the pattern. pattern, service, or procedure does not diminish the pilot’s responsibility to see and avoid other aircraft during flight. When entering the traffic pattern at an airport without an operating control tower, inbound pilots are expected to Standard Airport Traffic Patterns observe other aircraft already in the pattern and to conform to the traffic pattern in use. If there are no other aircraft present, To assure that air traffic flows into and out of an airport in an the pilot should check traffic indicators on the ground and orderly manner, an airport traffic pattern is established based wind indicators to determine which runway and traffic pattern on the local conditions, to include the direction and altitude direction to use. [Figure 7-2] Many airports have L-shaped of the pattern and the procedures for entering and leaving the traffic pattern indicators displayed with a segmented circle pattern. Unless the airport displays approved visual markings adjacent to the runway. The short member of the L shows indicating that turns should be made to the right, the pilot the direction in which the traffic pattern turns are made should make all turns in the pattern to the left. when using the runway parallel to the long member. The pilot should check the indicators from a distance or altitude When operating at an airport with an operating control tower, well away from any other airplanes that may be flying in the the pilot receives a clearance to approach or depart, as well traffic pattern. Upon identifying the proper traffic pattern, as pertinent information about the traffic pattern by radio. If the pilot should enter into the traffic pattern at a point well there is not a control tower, it is the pilot’s responsibility to clear of the other airplanes. determine the direction of the traffic pattern, to comply with the appropriate traffic rules, and to display common courtesy toward other pilots operating in the area. 7-2
Crosswind W Entry IN D 18Left-Hand Traffic Pattern Downwind 18 Departure Base 36 Final Crosswind Entry D IN W Right-Hand Traffic Pattern Departure Downwind 36 Final Base Figure 7-1. Traffic patterns. When approaching an airport for landing, the traffic pattern is leg. Entries into traffic patterns while descending create normally entered at a 45° angle to the downwind leg, headed specific collision hazards and should always be avoided. toward a point abeam the midpoint of the runway to be used for landing. When arriving, the pilot should be aware of the The pilot should ensure that the entry leg is of sufficient proper traffic pattern altitude before entering the pattern and length to provide a clear view of the entire traffic pattern remain clear of the traffic flow until established on the entry 7-3
Traffic pattern indicators (indicates location of base leg) with another aircraft that is already established on the final approach. Pilots must not attempt an overly steep turn to final, especially uncoordinated! If in doubt, go around. The final approach leg is a descending flightpath starting from the completion of the base-to-final turn and extending to the point of touchdown. This is probably the most important leg of the entire pattern, because of the sound judgment and precision required to accurately control the airspeed and descent angle while approaching the intended touchdown point. Windsock 14 CFR part 91, states that aircraft, while on final approach to land or while landing, have the right-of-way over other Segmented circle aircraft in flight or operating on the surface. When two or Figure 7-2. Traffic pattern indicators. more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right-of- and to allow adequate time for planning the intended path in way. Pilots should not take advantage of this rule to cut in the pattern and the landing approach. front of another aircraft that is on final approach to land or to overtake that aircraft. The upwind leg is a course flown parallel to the landing runway in the same direction as landing traffic. The upwind leg is flown at controlled airports and after go-arounds. The downwind leg is a course flown parallel to the landing When necessary, the upwind leg is the part of the traffic runway, but in a direction opposite to the intended landing pattern in which the pilot will transition from the final direction. This leg is flown approximately 1⁄2 to 1 mile out approach to the climb altitude to initiate a go-around. When a from the landing runway and at the specified traffic pattern safe altitude is attained, the pilot should commence a shallow altitude. When flying on the downwind leg, the pilot should bank turn to the upwind side of the airport. This allows better complete all before landing checks and extend the landing visibility of the runway for departing aircraft. gear if the airplane is equipped with retractable landing gear. Pattern altitude is maintained until at least abeam the The departure leg of the rectangular pattern is a straight course approach end of the landing runway. At this point, the pilot aligned with, and leading from, the takeoff runway. This leg should reduce power and begin a descent. The pilot should begins at the point the airplane leaves the ground and continues continue the downwind leg past a point abeam the approach until the pilot begins the 90° turn onto the crosswind leg. end of the runway to a point approximately 45° from the approach end of the runway, and make a medium bank turn On the departure leg after takeoff, the pilot should continue onto the base leg. Pilots should consider tailwinds and not climbing straight ahead and, if remaining in the traffic descend too much on the downwind, so as to have a very pattern, commence a turn to the crosswind leg beyond the low base leg altitude. departure end of the runway within 300 feet of the traffic pattern altitude. If departing the traffic pattern, the pilot The base leg is the transitional part of the traffic pattern should continue straight out or exit with a 45° turn (to the between the downwind leg and the final approach leg. left when in a left-hand traffic pattern; to the right when in Depending on the wind condition, the pilot should establish a right-hand traffic pattern) beyond the departure end of the the base leg at a sufficient distance from the approach end runway after reaching the traffic pattern altitude. of the landing runway to permit a gradual descent to the intended touchdown point. The ground track of the airplane The crosswind leg is the part of the rectangular pattern that while on the base leg is perpendicular to the extended is horizontally perpendicular to the extended centerline of centerline of the landing runway, although the longitudinal the takeoff runway. The pilot should enter the crosswind axis of the airplane may not be aligned with the ground track leg by making approximately a 90° turn from the upwind when it is necessary to turn into the wind to counteract drift. leg. The pilot should continue on the crosswind leg, to the While on the base leg, the pilot must ensure, before turning downwind leg position. onto the final approach, that there is no danger of colliding 7-4
Since in most cases the takeoff is made into the wind, the wind altitude, then turn right to enter at 45° to the downwind leg will now be approximately perpendicular to the airplane’s at midfield. [Figure 7-4A] An alternate method is to enter flightpath. As a result, the pilot should turn or head the on a midfield crosswind at pattern altitude, carefully scan airplane slightly into the wind while on the crosswind leg to for traffic, announce your intentions and then turned down maintain a ground track that is perpendicular to the runway downwind. [Figure 7-4B] This technique should not be used centerline extension. if the pattern is busy. Non-Towered Airports Always remember to give way to aircraft on the preferred 45° entry and to aircraft already established on downwind. Non towered airports traffic patterns are always entered at In either case, it is vital to announce your intentions, and pattern altitude. How you enter the pattern depends upon remember to scan outside. Before joining the downwind the direction of arrival. The preferred method for entering leg, adjust your course or speed to blend into the traffic. from the downwind leg side of the pattern is to approach Adjust power on the downwind leg, or sooner, to fit into the pattern on a course 45° to the downwind leg and join the the flow of traffic. Avoid flying too fast or too slow. Speeds pattern at midfield. recommended by the airplane manufacturer should be used. They will generally fall between 70 to 80 knots for fixed-gear There are several ways to enter the pattern if you are coming singles, and 80 to 90 knots for high-performance retractable. from the upwind legs side of the airport. One method of entry from the opposite side of the pattern is to announce your Safety Considerations intentions and cross over midfield at least 500 feet above pattern altitude (normally 1,500 feet AGL.) However, if large According to the National Transportation Safety Board or turbine aircraft operate at your airport, it is best to remain (NTSB), the most probable cause of mid-air collisions is 2,000 feet AGL so you’re not in conflict with their traffic the pilot failing to see and avoid other aircraft. When in pattern. When well clear of the pattern—approximately the traffic, pilots must continue to scan for other aircraft 2 miles—scan carefully for traffic, descend to pattern and check blind spots caused by fixed aircraft structures, AB Pattern altitude 1. Pattern altitude +500 feet 4. Yield to 2. Fly clear of Yield to the preferred downwind traffic pattern 45° and downwind traffic and (approx. 2 mi.) traffic, then turn enter downwind midfield 3. Descend to downwind pattern altitude, at 45° then turn Figure 7-4. Preferred entry from upwind leg side of airport (A). Alternate midfield entry from upwind leg side of airport (B). 7-5
such as doorposts and wings. High-wing airplanes have The following are some important procedures that all pilots restricted visibility above while low-wing airplanes have should be follow when flying in a traffic pattern or in the limited visibility below. The worst-case scenario is a low- vicinity of an airport. wing airplane flying above a high-wing airplane. Banking from time to time can uncover blind spots. The pilot should • Tune and verify radio frequencies before entering the also occasionally look to the rear of the airplane to check airport traffic area. for other aircraft. Figure 7-5 depicts the greatest threat area for mid-air collisions in the traffic pattern. Listed below are • Report your position 10 miles out and listen for reports important facts regarding mid-air collisions: from other inbound traffic. • Mid-air collisions generally occur during daylight • Report when you are entering downwind, turning hours; 56 percent of the accidents occur in the downwind to base, and base to final. This is a good afternoon, 32 percent occur in the morning, and 2 practice at a non-towered airport. percent occur at night, dusk, or dawn. • Descend to traffic pattern altitude before entering the • Most mid-air collisions occur under good visibility. pattern. • A mid-air collision is most likely to occur between • Maintain a constant visual scan for other aircraft. two aircraft going in the same direction. • Tune and monitor the correct Common Traffic • The majority of pilots involved in mid-air collisions Advisory Frequency (CTAF) frequency. are not on a flight plan. • Be aware that there may be aircraft in the pattern • Nearly all accidents occur at or near uncontrolled without radios. airports and at altitudes below 1,000 feet. • Use exterior lights to improve the chances of being • Pilots of all experience levels are involved in mid-air seen. collisions. Chapter Summary Distribution of Mid-Air Collisions in the Airport Traffic Pattern The volume of traffic at an airport can create a hazardous environment. Airport traffic patterns are procedures that 30% 34% 34% improve the flow of traffic at an airport and when properly executed enhance safety. Most reported mid-air collisions occur during the final or short final approach leg of the airport traffic pattern. 20% 16% 16% 10% Downwind Final Short final Runway 0% Figure 7-5. Location distribution of mid-air collisions in the airport traffic pattern. 7-6
AChappterp8roaches and Landings Introduction There is a saying that while takeoff is optional, landing is mandatory. Unfortunately, a review of accident statistics indicates that over 45 percent of all general aviation accidents occur during the approach and landing phases of a flight. A closer look shows that the cause of over 90 percent of those cases was pilot related and loss of control was also a major contributing factor in 33 percent of the cases. While the requirement to maneuver close to the ground cannot be eliminated, pilots can develop the skills and follow established procedures to reduce the likelihood of an accident or mishap. This chapter focuses on the approach to landing, factors that affect landings, types of landings, and aspects of faulty landings. 8-1
Normal Approach and Landing It must be remembered that the manufacturer’s recommended procedures, including airplane configuration and airspeeds, A normal approach and landing involves the use of procedures and other information relevant to approaches and landings in a for what is considered a normal situation; that is, when engine specific make and model airplane are contained in the Federal power is available, the wind is light, or the final approach is Aviation Administration (FAA)-approved Airplane Flight made directly into the wind, the final approach path has no Manual and/or Pilot’s Operating Handbook (AFM/POH) obstacles and the landing surface is firm and of ample length for that airplane. If any of the information in this chapter to gradually bring the airplane to a stop. The selected landing differs from the airplane manufacturer’s recommendations point is normally beyond the runway’s approach threshold as contained in the AFM/POH, the airplane manufacturer’s but within the first 1⁄3 portion of the runway. recommendations take precedence. The factors involved and the procedures described for the Base Leg normal approach and landing also have applications to the The placement of the base leg is one of the more important other-than-normal approaches and landings and are discussed judgments made by the pilot in any landing approach. later in this chapter. This being the case, the principles of [Figure 8-1] The pilot must accurately judge the altitude normal operations are explained first and must be understood and distance from which a gradual, stabilized descent results before proceeding to the more complex operations. To help in landing at the desired spot. The distance depends on the the pilot better understand the factors that influence judgment altitude of the base leg, the effect of wind, and the amount and procedures, the last part of the approach pattern and the of wing flaps used. When there is a strong wind on final actual landing is divided into five phases: approach or the flaps are used to produce a steep angle of descent, the base leg must be positioned closer to the 1. the base leg approach end of the runway than would be required with a light wind or no flaps. Normally, the landing gear is extended 2. the final approach and the before-landing check completed prior to reaching the base leg. 3. the round out (flare) After turning onto the base leg, start the descent with reduced 4. the touchdown power and airspeed of approximately 1.4 VSO, which is the 5. the after-landing roll 18 36 Figure 8-1. Base leg and final approach. 8-2
stalling speed with power off, landing gear and flaps down. of the runway or landing surface so that drift (if any) is For example, if VSO is 60 knots, the speed should be 1.4 times recognized immediately. On a normal approach, with no 60 or 84 knots. Landing flaps may be partially lowered, if wind drift, the longitudinal axis is kept aligned with the desired, at this time. Full flaps are not recommended until the runway centerline throughout the approach and landing. (The final approach is established. A drift correction is established proper way to correct for a crosswind is explained under the and maintained to follow a ground track perpendicular to section, Crosswind Approach and Landing. For now, only the extension of the centerline of the runway on which the an approach and landing where the wind is straight down the landing is to be made. Since the final approach and landing runway are discussed.) are normally made into the wind, there is somewhat of a crosswind during the base leg. This requires that the airplane After aligning the airplane with the runway centerline, the be angled sufficiently into the wind to prevent drifting farther final flap setting is completed and the pitch attitude adjusted away from the intended landing spot. as required for the desired rate of descent. Slight adjustments in pitch and power may be necessary to maintain the descent The base leg is continued to the point where a medium to attitude and the desired approach airspeed. In the absence of shallow-banked turn aligns the airplane’s path directly with the manufacturer’s recommended airspeed, a speed equal to the centerline of the landing runway. This descending turn is 1.3 VSO should be used. If VSO is 60 knots, the speed should completed at a safe altitude and dependent upon the height be 78 knots. When the pitch attitude and airspeed have been of the terrain and any obstructions along the ground track. stabilized, the airplane is re-trimmed to relieve the pressures The turn to the final approach is sufficiently above the airport being held on the controls. elevation to permit a final approach long enough to accurately estimate the resultant point of touchdown while maintaining A stabilized descent angle is controlled throughout the the proper approach airspeed. This requires careful planning approach so that the airplane lands in the center of the first as to the starting point and the radius of the turn. Normally, it third of the runway. The descent angle is affected by all four is recommended that the angle of bank not exceed a medium fundamental forces that act on an airplane (lift, drag, thrust, bank because the steeper the angle of bank, the higher the and weight). If all the forces are constant, the descent angle airspeed at which the airplane stalls. Since the base-to-final is constant in a no-wind condition. The pilot controls these turn is made at a relatively low altitude, it is important that forces by adjusting the airspeed, attitude, power, and drag a stall not occur at this point. If an extremely steep bank is (flaps or forward slip). The wind also plays a prominent part needed to prevent overshooting the proper final approach in the gliding distance over the ground [Figure 8-2]; the path, it is advisable to discontinue the approach, go around, pilot does not have control over the wind but corrects for and plan to start the turn earlier on the next approach rather its effect on the airplane’s descent by appropriate pitch and than risk a hazardous situation. power adjustments. Final Approach Considering the factors that affect the descent angle on the After the base-to-final approach turn is completed, the final approach, for all practical purposes at a given pitch longitudinal axis of the airplane is aligned with the centerline attitude there is only one power setting for one airspeed, one Strong headwind speed flightpath airspeed flightpath best glide Normal Increased 34 Figure 8-2. Effect of headwind on final approach. 8-3
flap setting, and one wind condition. A change in any one of • Producing greater drag, permitting a steeper descent these variables requires an appropriate coordinated change angle without airspeed increase, and in the other controllable variables. For example, if the pitch attitude is raised too high without an increase of power, the • Reducing the length of the landing roll. airplane settles very rapidly and touches down short of the desired spot. For this reason, never try to stretch a glide by Flap extension has a definite effect on the airplane’s pitch applying back-elevator pressure alone to reach the desired behavior. The increased camber from flap deflection landing spot. This shortens the gliding distance if power is produces lift primarily on the rear portion of the wing. This not added simultaneously. The proper angle of descent and produces a nose-down pitching moment; however, the change airspeed is maintained by coordinating pitch attitude changes in tail loads from the downwash deflected by the flaps over and power changes. the horizontal tail has a significant influence on the pitching moment. Consequently, pitch behavior depends on the design The objective of a good, stabilized final approach is to features of the particular airplane. descend at an angle and airspeed that permits the airplane to reach the desired touchdown point at an airspeed that results Flap deflection of up to 15° primarily produces lift with in minimum floating just before touchdown; in essence, a minimal drag. The airplane has a tendency to balloon up with semi-stalled condition. To accomplish this, it is essential initial flap deflection because of the lift increase. The nose- that both the descent angle and the airspeed be accurately down pitching moment, however, tends to offset the balloon. controlled. Since on a normal approach the power setting is Flap deflection beyond 15° produces a large increase in drag. not fixed as in a power-off approach, the power and pitch Also, deflection beyond 15° produces a significant nose-up attitude are adjusted simultaneously as necessary to control pitching moment in high-wing airplanes because the resulting the airspeed and the descent angle, or to attain the desired downwash increases the airflow over the horizontal tail. altitudes along the approach path. By lowering the nose and reducing power to keep approach airspeed constant, a descent The time of flap extension and the degree of deflection at a higher rate can be made to correct for being too high in are related. Large flap deflections at one single point in the approach. This is one reason for performing approaches the landing pattern produce large lift changes that require with partial power; if the approach is too high, merely lower significant pitch and power changes in order to maintain the nose and reduce the power. When the approach is too airspeed and descent angle. Consequently, there is an low, add power and raise the nose. advantage to extending flaps in increments while in the landing pattern. Incremental deflection of flaps on downwind, Use of Flaps base leg, and final approach allow smaller adjustments of The lift/drag factors are varied by the pilot to adjust the descent pitch and power compared to extension of full flaps all at through the use of landing flaps. [Figures 8-3 and 8-4] Flap one time. extension during landings provides several advantages by: When the flaps are lowered, the airspeed decreases unless • Producing greater lift and permitting lower landing the power is increased or the pitch attitude lowered. On final speed, approach, the pilot must estimate where the airplane lands with: constant airspeed constant power Full flaps Half flaps No flaps 34 Figure 8-3. Effect of flaps on the landing point. 8-4
No flaps; flatter descent angle Half flaps Full flaps; steeper descent angle with: constant airspeed constant power 34 Figure 8-4. Effect of flaps on the approach angle. through judgment of the descent angle. If it appears that the requires that the vision be focused properly in order that the airplane is going to overshoot the desired landing spot, more important objects stand out as clearly as possible. flaps are used, if not fully extended, or the power reduced further and the pitch attitude lowered. This results in a steeper Speed blurs objects at close range. For example, most approach. If the desired landing spot is being undershot and a everyone has noted this in an automobile moving at high shallower approach is needed, both power and pitch attitude speed. Nearby objects seem to merge together in a blur, are increased to readjust the descent angle. Never retract while objects farther away stand out clearly. The driver the flaps to correct for undershooting since that suddenly subconsciously focuses the eyes sufficiently far ahead of the decreases the lift and causes the airplane to sink rapidly. automobile to see objects distinctly. The airplane must be re-trimmed on the final approach to The distance at which the pilot’s vision is focused should be compensate for the change in aerodynamic forces. With proportionate to the speed at which the airplane is traveling the reduced power and with a slower airspeed, the airflow over the ground. Thus, as speed is reduced during the round produces less lift on the wings and less downward force on out, the distance ahead of the airplane at which it is possible the horizontal stabilizer resulting in a significant nose-down to focus is brought closer accordingly. tendency. The elevator must then be trimmed more nose-up. If the pilot attempts to focus on a reference that is too close The round out, touchdown, and landing roll are much easier or looks directly down, the reference becomes blurred, to accomplish when they are preceded by a proper final [Figure 8-5] and the reaction is either too abrupt or too late. approach consisting of precise control of airspeed, attitude, In this case, the pilot’s tendency is to over-control, round power, and drag resulting in a stabilized descent angle. out high, and make full-stall, drop-in landings. If the pilot focuses too far ahead, accuracy in judging the closeness of Estimating Height and Movement the ground is lost and the consequent reaction is too slow During the approach, round out, and touchdown; vision is since there does not appear to be a necessity for action. This of prime importance. To provide a wide scope of vision and results in the airplane flying into the ground nose first. The to foster good judgment of height and movement, the pilot’s change of visual focus from a long distance to a short distance head should assume a natural, straight-ahead position. Visual requires a definite time interval and, even though the time focus is not fixed on any one side or any one spot ahead of is brief, the airplane’s speed during this interval is such that the airplane. Instead, it is changed slowly from a point just the airplane travels an appreciable distance, both forward over the airplane’s nose to the desired touchdown zone and and downward toward the ground. back again. This is done while maintaining a deliberate awareness of distance from either side of the runway using If the focus is changed gradually, being brought progressively your peripheral field of vision. closer as speed is reduced, the time interval and the pilot’s reaction are reduced and the whole landing process smoothed out. Accurate estimation of distance is, besides being a matter of practice, dependent upon how clearly objects are seen. It 8-5
When the AOA is increased, the lift is momentarily increased and this decreases the rate of descent. Since power normally is reduced to idle during the round out, the airspeed also gradually decreases. This causes lift to decrease again and necessitates raising the nose and further increasing the AOA. During the round out, the airspeed is decreased to touchdown speed while the lift is controlled so the airplane settles gently onto the landing surface. The round out is executed at a rate that the proper landing attitude and the proper touchdown airspeed are attained simultaneously just as the wheels contact the landing surface. Figure 8-5. Focusing too close blurs vision. The rate at which the round out is executed depends on the airplane’s height above the ground, the rate of descent, and Round Out (Flare) the pitch attitude. A round out started excessively high must The round out is a slow, smooth transition from a normal be executed more slowly than one from a lower height to approach attitude to a landing attitude, gradually rounding allow the airplane to descend to the ground while the proper out the flightpath to one that is parallel with, and within a landing attitude is being established. The rate of rounding very few inches above, the runway. When the airplane, in a out must also be proportionate to the rate of closure with normal descent, approaches within what appears to be 10 to the ground. When the airplane appears to be descending 20 feet above the ground, the round out or flare is started. very slowly, the increase in pitch attitude must be made at a This is a continuous process until the airplane touches down correspondingly slow rate. on the ground. Visual cues are important in flaring at the proper altitude and As the airplane reaches a height above the ground where a maintaining the wheels a few inches above the runway until change into the proper landing attitude can be made, back- eventual touchdown. Flare cues are primarily dependent on elevator pressure is gradually applied to slowly increase the the angle at which the pilot’s central vision intersects the pitch attitude and angle of attack (AOA). [Figure 8-6] This ground (or runway) ahead and slightly to the side. Proper depth causes the airplane’s nose to gradually rise toward the desired perception is a factor in a successful flare, but the visual cues landing attitude. The AOA is increased at a rate that allows the used most are those related to changes in runway or terrain airplane to continue settling slowly as forward speed decreases. perspective and to changes in the size of familiar objects near the landing area, such as fences, bushes, trees, hangars, and even sod or runway texture. Focus direct central vision at a shallow downward angle from 10° to 15° toward the runway as the round out/flare is initiated. [Figure 8-7] Maintaining the same viewing angle causes the point of visual interception with 78 knots Increase angle of attack 70 knots Increase angle of attack Increase angle of attack 65 knots 60 knots 34 Figure 8-6. Changing angle of attack during roundout. 8-6
10° to 15° 27 Figure 8-7. To obtain necessary visual cues, the pilot should look toward the runway at a shallow angle. the runway to move progressively rearward as the airplane Touchdown loses altitude. This is an important visual cue in assessing the The touchdown is the gentle settling of the airplane onto the rate of altitude loss. Conversely, forward movement of the landing surface. The round out and touchdown are normally visual interception point indicates an increase in altitude and made with the engine idling and the airplane at minimum means that the pitch angle was increased too rapidly, resulting controllable airspeed so that the airplane touches down on in an over flare. Location of the visual interception point the main gear at approximately stalling speed. As the airplane in conjunction with assessment of flow velocity of nearby settles, the proper landing attitude is attained by application off-runway terrain, as well as the similarity of appearance of of whatever back-elevator pressure is necessary. height above the runway ahead of the airplane (in comparison to the way it looked when the airplane was taxied prior to Some pilots try to force or fly the airplane onto the ground takeoff), is also used to judge when the wheels are just a few without establishing the proper landing attitude. The airplane inches above the runway. should never be flown on the runway with excessive speed. A common technique to making a smooth touchdown is to The pitch attitude of the airplane in a full-flap approach is actually focus on holding the wheels of the aircraft a few considerably lower than in a no-flap approach. To attain inches off the ground as long as possible using the elevators the proper landing attitude before touching down, the nose while the power is smoothly reduced to idle. In most cases, must travel through a greater pitch change when flaps are when the wheels are within 2 or 3 feet off the ground, the fully extended. Since the round out is usually started at airplane is still settling too fast for a gentle touchdown; approximately the same height above the ground regardless of therefore, this descent must be retarded by increasing back- the degree of flaps used, the pitch attitude must be increased elevator pressure. Since the airplane is already close to at a faster rate when full flaps are used; however, the round its stalling speed and is settling, this added back-elevator out is still be executed at a rate proportionate to the airplane’s pressure only slows the settling instead of stopping it. At downward motion. the same time, it results in the airplane touching the ground in the proper landing attitude and the main wheels touching Once the actual process of rounding out is started, do not down first so that little or no weight is on the nose wheel. push the elevator control forward. If too much back-elevator [Figure 8-8] pressure was exerted, this pressure is either slightly relaxed or held constant, depending on the degree of the error. In some After the main wheels make initial contact with the ground, cases, it may be necessary to advance the throttle slightly to back-elevator pressure is held to maintain a positive AOA prevent an excessive rate of sink or a stall, either of which for aerodynamic braking and to hold the nose wheel off results in a hard, drop-in type landing. the ground until the airplane decelerates. As the airplane’s momentum decreases, back-elevator pressure is gradually It is recommended that a pilot form the habit of keeping one relaxed to allow the nose wheel to gently settle onto the hand on the throttle throughout the approach and landing runway. This permits steering with the nose wheel. At the should a sudden and unexpected hazardous situation require same time, it decreases the AOA and reduces lift on the wings an immediate application of power. 8-7
15 feet Near zero rate of descent 1 foot 2 to 3 feet Figure 8-8. A well-executed roundout results in attaining the proper landing attitude. to prevent floating or skipping and allows the full weight of when more positive control is required than could be obtained the airplane to rest on the wheels for better braking action. with rudder or nose wheel steering alone. It is extremely important that the touchdown occur with the To use brakes, on an airplane equipped with toe brakes, the airplane’s longitudinal axis exactly parallel to the direction pilot slides the toes or feet up from the rudder pedals to the in which the airplane is moving along the runway. Failure brake pedals. If rudder pressure is being held at the time to accomplish this imposes severe side loads on the landing braking action is needed, that pressure is not to be released as gear. To avoid these side stresses, do not allow the airplane the feet or toes are being slid up to the brake pedals because to touch down while turned into the wind or drifting. control may be lost before brakes can be applied. After-Landing Roll Putting maximum weight on the wheels after touchdown is an The landing process must never be considered complete until important factor in obtaining optimum braking performance. the airplane decelerates to the normal taxi speed during the During the early part of rollout, some lift continues to be landing roll or has been brought to a complete stop when clear generated by the wing. After touchdown, the nose wheel of the landing area. Numerous accidents occur as a result is lowered to the runway to maintain directional control. of pilots abandoning their vigilance and failing to maintain During deceleration, the nose may pitch down by braking positive control after getting the airplane on the ground. and the weight transferred to the nose wheel from the main wheels. This does not aid in braking action, so back pressure A pilot must be alert for directional control difficulties is applied to the controls without lifting the nose wheel off immediately upon and after touchdown due to the ground the runway. This enables directional control while keeping friction on the wheels. Loss of directional control may lead weight on the main wheels. to an aggravated, uncontrolled, tight turn on the ground, or a ground loop. The combination of centrifugal force acting Careful application of the brakes is initiated after the nose on the center of gravity (CG) and ground friction of the wheel is on the ground and directional control is established. main wheels resisting it during the ground loop may cause Maximum brake effectiveness is just short of the point where the airplane to tip or lean enough for the outside wingtip to skidding occurs. If the brakes are applied so hard that skidding contact the ground. This imposes a sideward force that could takes place, braking becomes ineffective. Skidding is stopped collapse the landing gear. by releasing the brake pressure. Braking effectiveness is not enhanced by alternately applying, releasing, and reapplying The rudder serves the same purpose on the ground as it brake pressure. The brakes are applied firmly and smoothly does in the air—it controls the yawing of the airplane. The as necessary. effectiveness of the rudder is dependent on the airflow, which depends on the speed of the airplane. As the speed decreases During the ground roll, the airplane’s direction of movement and the nose wheel has been lowered to the ground, the can be changed by carefully applying pressure on one brake steerable nose provides more positive directional control. or uneven pressures on each brake in the desired direction. Caution must be exercised when applying brakes to The brakes of an airplane serve the same primary purpose as avoid overcontrolling. the brakes of an automobile—to reduce speed on the ground. In airplanes, they are also used as an aid in directional control 8-8
The ailerons serve the same purpose on the ground as they touches down because some float occurs during the round out do in the air—they change the lift and drag components of (flare). [Figure 8-9] Neither is it the spot toward which the the wings. During the after-landing roll, they are used to keep airplane’s nose is pointed because the airplane is flying at a the wings level in much the same way they are used in flight. fairly high AOA, and the component of lift exerted parallel If a wing starts to rise, aileron control is applied toward that to the Earth’s surface by the wings tends to carry the airplane wing to lower it. The amount required depends on speed forward horizontally. because as the forward speed of the airplane decreases, the ailerons become less effective. Procedures for using ailerons The point toward which the airplane is progressing is termed in crosswind conditions are explained further in this chapter, the “aiming point.” [Figure 8-9] It is the point on the ground in the Crosswind Approach and Landing section. at which, if the airplane maintains a constant glide path and was not flared for landing, it would strike the ground. To a After the airplane is on the ground, back-elevator pressure is pilot moving straight ahead toward an object, it appears to be gradually relaxed to place weight on the nose wheel to aid in stationary. It does not appear to move under the nose of the better steering. If available runway permits, the speed of the aircraft and does not appear to move forward away from the airplane is allowed to dissipate in a normal manner. Once aircraft. This is how the aiming point can be distinguished—it the airplane has slowed sufficiently and has turned on to the does not move. However, objects in front of and beyond the taxiway and stopped, retract the flaps and perform the after- aiming point do appear to move as the distance is closed, and landing checklist. Many accidents have occurred as a result they appear to move in opposite directions. During instruction of the pilot unintentionally operating the landing gear control in landings, one of the most important skills a pilot must and retracting the gear instead of the flap control when the acquire is how to use visual cues to accurately determine the airplane was still rolling. The habit of positively identifying true aiming point from any distance out on final approach. both of these controls, before actuating them, must be formed From this, the pilot is not only able to determine if the glide from the very beginning of flight training and continued in path results in either an under or overshoot but, taking into all future flying activities. account float during round out, the pilot is able to predict the touchdown point to within a few feet. Stabilized Approach Concept A stabilized approach is one in which the pilot establishes For a constant angle glide path, the distance between the and maintains a constant angle glide path towards a horizon and the aiming point remains constant. If a final predetermined point on the landing runway. It is based on approach descent is established and the distance between the the pilot’s judgment of certain visual clues and depends on perceived aiming point and the horizon appears to increase the maintenance of a constant final descent airspeed and (aiming point moving down away from the horizon), then configuration. the true aiming point, and subsequent touchdown point, is farther down the runway. If the distance between the An airplane descending on final approach at a constant rate perceived aiming point and the horizon decreases, meaning and airspeed is traveling in a straight line toward a spot on the that the aiming point is moving up toward the horizon, the ground ahead. This spot is not the spot on which the airplane true aiming point is closer than perceived. Aiming point (descent angle intersects ground) Touchdown 34 Distance traveled in flare Figure 8-9. Stabilized approach. 8-9
3° approach angle Same runway, same approach angle Same runway, same approach angle 400 feet x 100 feet runway 800 feet from threshold 400 feet from threshold 1,600 feet from threshold 52 feet altitude 26 feet altitude 105 feet altitude Figure 8-10. Runway shape during stabilized approach. When the airplane is established on final approach, the shape out on final approach, adjust the pitch attitude and power so of the runway image also presents clues as to what must be that the airplane is descending directly toward the aiming done to maintain a stabilized approach to a safe landing. point at the appropriate airspeed, in the landing configuration, and trimmed for “hands off” flight. With the approach set Obviously, runway is normally shaped in the form of an up in this manner, the pilot is free to devote full attention elongated rectangle. When viewed from the air during the toward outside references. Do not stare at any one place, approach, the phenomenon known as perspective causes the but rather scan from one point to another, such as from the runway to assume the shape of a trapezoid with the far end aiming point to the horizon, to the trees and bushes along looking narrower than the approach end and the edge lines the runway, to an area well short of the runway, and back to converging ahead. the aiming point. This makes it easier to perceive a deviation from the desired glide path and determine if the airplane is As an airplane continues down the glide path at a constant proceeding directly toward the aiming point. angle (stabilized), the image the pilot sees is still trapezoidal but of proportionately larger dimensions. In other words, If there is any indication that the aiming point on the runway during a stabilized approach, the runway shape does not is not where desired, an adjustment must be made to the glide change. [Figure 8-10] path. This in turn moves the aiming point. For instance, if the aiming point is short of the desired touchdown point If the approach becomes shallow, the runway appears to and results in an undershoot, an increase in pitch attitude shorten and become wider. Conversely, if the approach and engine power is warranted. A constant airspeed must is steepened, the runway appears to become longer and be maintained. The pitch and power change, therefore, narrower. [Figure 8-11] must be made smoothly and simultaneously. This results in a shallowing of the glide path with the aiming point moving The objective of a stabilized approach is to select an towards the desired touchdown point. Conversely, if the appropriate touchdown point on the runway, and adjust aiming point is farther down the runway than the desired the glide path so that the true aiming point and the desired touchdown point resulting in an overshoot, the glide path is touchdown point basically coincide. Immediately after rolling steepened by a simultaneous decrease in pitch attitude and Too high Proper descent angle Too low Figure 8-11. Change in runway shape if approach becomes narrow or steep. 8-10
power. Once again, the airspeed must be held constant. It A slip is a combination of forward movement and sideward is essential that deviations from the desired glide path be (with respect to the longitudinal axis of the airplane) detected early so that only slight and infrequent adjustments movement, the lateral axis being inclined and the sideward to glide path are required. movement being toward the low end of this axis (low wing). An airplane in a slip is in fact flying sideways, which results The closer the airplane gets to the runway, the larger and in a change in the direction that the relative wind strikes the more frequent the required corrections become, resulting in airplane. Slips are characterized by a marked increase in drag an unstable approach. Common errors in the performance of and corresponding decrease in airplane climb, cruise, and normal approaches and landings are: glide performance. It is the increase in drag, however, that makes it possible for an airplane in a slip to descend rapidly • Inadequate wind drift correction on the base leg. without an increase in airspeed. • Overshooting or undershooting the turn onto final Most airplanes exhibit the characteristic of positive static approach resulting in too steep or too shallow a turn directional stability and, therefore, have a natural tendency onto final approach. to compensate for slipping. An intentional slip, therefore, requires deliberate cross-controlling ailerons and rudder • Flat or skidding turns from base leg to final approach throughout the maneuver. as a result of overshooting/inadequate wind drift correction. A “sideslip” is entered by lowering a wing and applying just enough opposite rudder to prevent a turn. In a sideslip, the • Poor coordination during turn from base to final airplane’s longitudinal axis remains parallel to the original approach. flightpath, but the airplane no longer flies straight ahead. Instead, the horizontal component of wing lift forces the • Failure to complete the landing checklist in a timely airplane also to move somewhat sideways toward the low manner. wing. [Figure 8-12] The amount of slip, and therefore the • Unstable approach. Direction of movement • Failure to adequately compensate for flap extension. Relative wind • Poor trim technique on final approach. • Attempting to maintain altitude or reach the runway using elevator alone. • Focusing too close to the airplane resulting in a too high round out. • Focusing too far from the airplane resulting in a too low round out. • Touching down prior to attaining proper landing attitude. • Failure to hold sufficient back-elevator pressure after touchdown. • Excessive braking after touchdown. • Loss of aircraft control during touchdown and roll out. Intentional Slips Sideslip A slip occurs when the bank angle of an airplane is too steep Figure 8-12. Sideslip. for the existing rate of turn. Unintentional slips are most often the result of uncoordinated rudder/aileron application. Intentional slips, however, are used to dissipate altitude without increasing airspeed and/or to adjust airplane ground track during a crosswind. Intentional slips are especially useful in forced landings and in situations where obstacles must be cleared during approaches to confined areas. A slip can also be used as an emergency means of rapidly reducing airspeed in situations where wing flaps are inoperative or not installed. 8-11
rate of sideward movement, is determined by the bank is required to maintain heading even though the ailerons angle. The steeper the bank is, the greater the degree of are capable of further steepening the bank angle. This is slip. As bank angle is increased additional opposite rudder the practical slip limit because any additional bank would is required to prevent turning. Sideslips are frequently used cause the airplane to turn even though full opposite rudder when landing with a crosswind to keep the aircraft aligned is being applied. If there is a need to descend more rapidly, with the runway centerline while stopping any drift left or even though the practical slip limit has been reached, right of the centerline. lowering the nose not only increases the sink rate but also increases airspeed. The increase in airspeed increases rudder A “forward slip” is one in which the airplane’s direction effectiveness permitting a steeper slip. Conversely, when the of motion continues the same as before the slip was begun. nose is raised, rudder effectiveness decreases and the bank Assuming the airplane is originally in straight flight, the angle must be reduced. wing on the side toward which the slip is to be made should be lowered by use of the ailerons. Simultaneously, the Discontinuing a slip is accomplished by leveling the wings airplane’s nose must be yawed in the opposite direction by and simultaneously releasing the rudder pressure while applying opposite rudder so that the airplane’s longitudinal readjusting the pitch attitude to the normal glide attitude. axis is at an angle to its original flightpath. [Figure 8-13] The If the pressure on the rudder is released abruptly, the nose degree to which the nose is yawed in the opposite direction swings too quickly into line and the airplane tends to acquire from the bank should be such that the original ground track excess speed. Because of the location of the pitot tube and is maintained. In a forward slip, the amount of slip, and static vents, airspeed indicators in some airplanes may have therefore the sink rate, is determined by the bank angle. The considerable error when the airplane is in a slip. The pilot steeper the bank is, the steeper the descent. must be aware of this possibility and recognize a properly performed slip by the attitude of the airplane, the sound of In most light airplanes, the steepness of a slip is limited by the airflow, and the feel of the flight controls. Unlike skids, the amount of rudder travel available. In both sideslips and however, if an airplane in a slip is made to stall, it displays forward slips, the point may be reached where full rudder very little of the yawing tendency that causes a skidding stall to develop into a spin. The airplane in a slip may do little Relative wind more than tend to roll into a wings level attitude. In fact, in some airplanes stall characteristics may even be improved. Direction of movement Go-Arounds (Rejected Landings) Whenever landing conditions are not satisfactory, a go- around is warranted. There are many factors that can contribute to unsatisfactory landing conditions. Situations such as air traffic control (ATC) requirements, unexpected appearance of hazards on the runway, overtaking another airplane, wind shear, wake turbulence, mechanical failure, and/or an unstable approach are all examples of reasons to discontinue a landing approach and make another approach under more favorable conditions. The assumption that an aborted landing is invariably the consequence of a poor approach, which in turn is due to insufficient experience or skill, is a fallacy. The go-around is not strictly an emergency procedure. It is a normal maneuver that is also used in an emergency situation. Like any other normal maneuver, the go-around must be practiced and perfected. The flight instructor needs to emphasize early on, and the pilot must be made to understand, that the go-around maneuver is an alternative to any approach and/or landing. Forward slip Although the need to discontinue a landing may arise at any Figure 8-13. Forward slip. point in the landing process, the most critical go-around is one started when very close to the ground. The earlier a condition that warrants a go-around is recognized, the safer 8-12
the go-around/rejected landing is. The go-around maneuver a stall from which the airplane could not be recovered if the is not inherently dangerous in itself. It becomes dangerous go-around is performed at a low altitude. only when delayed unduly or executed improperly. Delay in initiating the go-around normally stems from two sources: A concern for quickly regaining altitude during a go-around produces a natural tendency to pull the nose up. A pilot 1. Landing expectancy or set—the anticipatory belief that executing a go-around must accept the fact that an airplane conditions are not as threatening as they are and that cannot climb until it can fly, and it cannot fly below stall the approach is surely terminated with a safe landing, speed. In some circumstances, it is desirable to lower the nose briefly to gain airspeed. As soon as the appropriate 2. Pride—the mistaken belief that the act of going climb airspeed and pitch attitude are attained, “rough trim” around is an admission of failure—failure to execute the airplane to relieve any adverse control pressures. More the approach properly. The improper execution of the precise trim adjustments can be made when flight conditions go-around maneuver stems from a lack of familiarity have stabilized. with the three cardinal principles of the procedure: power, attitude, and configuration. Configuration After establishing the proper climb attitude and power Power settings, be concerned first with flaps and secondly with the Power is the pilot’s first concern. The instant a pilot decides to landing gear (if retractable). When the decision is made to go around, full or maximum allowable takeoff power must be perform a go-around, takeoff power is applied immediately applied smoothly and without hesitation and held until flying and the pitch attitude changed so as to slow or stop the speed and controllability are restored. Applying only partial descent. After the descent has been stopped, the landing power in a go-around is never appropriate. The pilot must be flaps are partially retracted or placed in the takeoff position aware of the degree of inertia that must be overcome before as recommended by the manufacturer. Caution must be used an airplane that is settling towards the ground can regain in retracting the flaps. Depending on the airplane’s altitude sufficient airspeed to become fully controllable and capable and airspeed, it is wise to retract the flaps intermittently in of climbing or turning safely. The application of power is small increments to allow time for the airplane to accelerate smooth, as well as positive. Abrupt movements of the throttle progressively as they are being raised. A sudden and complete in some airplanes causes the engine to falter. Carburetor heat retraction of the flaps could cause a loss of lift resulting in is turned off to obtain maximum power. the airplane settling into the ground. [Figure 8-14] Attitude Unless otherwise specified in the AFM/POH, it is generally Attitude is always critical when close to the ground, and when recommended that the flaps be retracted (at least partially) power is added, a deliberate effort on the part of the pilot before retracting the landing gear for two reasons. First, on is required to keep the nose from pitching up prematurely. most airplanes full flaps produce more drag than the landing The airplane executing a go-around must be maintained in gear; and second, in case the airplane inadvertently touches an attitude that permits a buildup of airspeed well beyond down as the go-around is initiated; it is most desirable to the stall point before any effort is made to gain altitude or to execute a turn. Raising the nose too early could result in Retract remaining 500 feet flaps cruise climb Timely decision to Apply max power, Positive rate of make go-around adjust pitch attitude, climb, retract gear, climb at VY and allow airspeed Assume climb attitude to increase flaps to intermediate Figure 8-14. Go-around procedure. 8-13
have the landing gear in the down-and-locked position. effect when initiating a go-around close to the ground. An After a positive rate of climb is established, the landing gear attempt to climb prematurely may result in the airplane not is retracted. being able to climb or even maintain altitude at full power. When takeoff power is applied, it is usually necessary to Common errors in the performance of go-arounds (rejected hold considerable pressure on the controls to maintain landings) are: straight flight and a safe climb attitude. Since the airplane is trimmed for the approach (a low power and low airspeed • Failure to recognize a condition that warrants a condition), application of maximum allowable power requires rejected landing considerable control pressure to maintain a climb pitch attitude. The addition of power tends to raise the airplane’s • Indecision nose suddenly and veer to the left. Forward elevator pressure must be anticipated and applied to hold the nose in a safe • Delay in initiating a go-around climb attitude. Right rudder pressure must be increased to counteract torque and P-factor and to keep the nose straight. • Failure to apply maximum allowable power in a timely The airplane must be held in the proper flight attitude manner regardless of the amount of control pressure that is required. Trim is applied to relieve adverse control pressures and assist • Abrupt power application in maintaining a proper pitch attitude. On airplanes that produce high control pressures when using maximum power • Improper pitch attitude on go-arounds, use caution when reaching for the flap handle. Airplane control is critical during this high-workload phase. • Failure to configure the airplane appropriately The landing gear is retracted only after the initial or rough trim • Attempting to climb out of ground effect prematurely is accomplished and when it is certain the airplane will remain airborne. During the initial part of an extremely low go- • Failure to adequately compensate for torque/P factor around, it is possible for the airplane to settle onto the runway and bounce. This situation is not particularly dangerous • Loss of aircraft control provided the airplane is kept straight and a constant, safe pitch attitude is maintained. With the application of power, the Crosswind Approach and Landing airplane attains a safe flying speed rapidly and the advanced power cushions any secondary touchdown. Many runways or landing areas are such that landings must be made while the wind is blowing across rather than parallel to the landing direction. All pilots must be prepared to cope with these situations when they arise. The same basic principles and factors involved in a normal approach and landing apply to a crosswind approach and landing; therefore, only the additional procedures required for correcting for wind drift are discussed here. If the pitch attitude is increased excessively in an effort Crosswind landings are a little more difficult to perform to keep the airplane from contacting the runway, it may than crosswind takeoffs, mainly due to different problems cause the airplane to stall. This is likely to occur if no trim involved in maintaining accurate control of the airplane while correction is made and the flaps remain fully extended. Do its speed is decreasing rather than increasing as on takeoff. not attempt to retract the landing gear until after a rough trim is accomplished and a positive rate of climb is established. There are two usual methods of accomplishing a crosswind approach and landing—the crab method and the wing-low Ground Effect (sideslip) method. Although the crab method may be easier for the pilot to maintain during final approach, it requires a Ground effect is a factor in every landing and every takeoff high degree of judgment and timing in removing the crab in fixed-wing airplanes. Ground effect can also be an immediately prior to touchdown. The wing-low method is important factor in go-arounds. If the go-around is made recommended in most cases, although a combination of both close to the ground, the airplane may be in the ground effect methods may be used. area. Pilots are often lulled into a sense of false security by the apparent “cushion of air” under the wings that initially Crosswind Final Approach assists in the transition from an approach descent to a climb. The crab method is executed by establishing a heading (crab) This “cushion of air,” however, is imaginary. The apparent toward the wind with the wings level so that the airplane’s increase in airplane performance is, in fact, due to a reduction ground track remains aligned with the centerline of the in induced drag in the ground effect area. It is “borrowed” runway. [Figure 8-15] This crab angle is maintained until performance that must be repaid when the airplane climbs just prior to touchdown, when the longitudinal axis of the out of the ground effect area. The pilot must factor in ground 8-14
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