Figure 9-17. Crosswind approach and landing.
To correct for strong crosswind, the slip into the wind is increased by lowering the upwind wing as needed. As a consequence, this results
in a greater tendency of the airplane to turn. Since turning is not desired, considerable opposite rudder is applied to keep the airplane’s
longitudinal axis aligned with the runway. In some airplanes, there may not be sufficient rudder travel available to compensate for the
strong turning tendency caused by the steep bank. If the required bank is such that full opposite rudder does not prevent a turn, the wind
is too strong to safely land the airplane on that particular runway with those wind conditions. Since the airplane’s capability is exceeded,
it is imperative that the landing be made on a more favorable runway either at that airport or at an alternate airport.
Flaps are used during most approaches since they tend to have a stabilizing effect on the airplane. The degree to which flaps are extended
vary with the airplane’s handling characteristics, as well as the wind velocity.
Crosswind Round Out (Flare)
Generally, the round out is made like a normal landing approach, but the application of a crosswind correction is continued as necessary
to prevent drifting.
Since the airspeed decreases as the round out progresses, the flight controls gradually become less effective. As a result, the crosswind
correction being held becomes inadequate. When using the wing-low method, it is necessary to gradually increase the deflection of the
rudder and ailerons to maintain the proper amount of drift correction.
Keep the upwind wing down throughout the round out. If the wings are leveled, the airplane begins drifting and the touchdown occurs
while drifting. Remember, the primary objective is to land the airplane without subjecting it to any side loads that result from touching
down while drifting.
Crosswind Touchdown
If the crab method of drift correction is used throughout the final approach and round out, the crab needs to be removed the instant before
touchdown by applying rudder to align the airplane’s longitudinal axis with its direction of movement.
If the wing-low method is used, the crosswind correction is maintained throughout the round out, and the initial touchdown occurs on the
upwind main wheel. During gusty or high wind conditions, prompt adjustments are made in the crosswind correction to assure that the
airplane does not drift as the airplane touches down. As the forward momentum decreases after initial contact, the weight of the airplane
causes the downwind main wheel to gradually settle onto the runway.
In those airplanes having nose-wheel steering interconnected with the rudder, the nose-wheel is not aligned with the runway as the main
wheels touch down because opposite rudder is being held for the crosswind correction. To prevent swerving in the direction the nose-
wheel is offset, the corrective rudder pressure needs to be relaxed as the nose-wheel touches down.
Crosswind After-Landing Roll
Particularly during the after-landing roll, special attention should be given to maintaining directional control by the use of rudder or
nose-wheel steering, while keeping the upwind wing from rising by the use of aileron. When an airplane is airborne, it moves with the
air mass in which it is flying regardless of the airplane’s heading and speed. When an airplane is on the ground, it is unable to move with
the air mass (crosswind) because of the resistance created by ground friction on the wheels.
Characteristically, an airplane has a greater profile or side area behind the main landing gear than forward of the gear. With the main
wheels acting as a pivot point and the greater surface area exposed to the crosswind behind that pivot point, the airplane tends to turn or
weathervane into the wind.
The relative wind acting on an airplane during the after-landing roll is the result of two factors. One is the natural wind, which acts in
the direction the air mass is traveling. It has a headwind component acting along the airplane’s ground track and a crosswind component
acting 90° to its track. The other factor is the wind induced by the forward movement of the airplane, which acts parallel and opposite to
the direction of movement. The relative wind is the resultant of these two factors and acts from a direction somewhere between the two
components. The faster the airplane’s groundspeed, the more the relative wind aligns towards the nose of the aircraft. As the airplane’s
forward speed decreases during the after-landing roll, the forward component of the relative wind decreases, causing the relative wind to
act in a direction more aligned with the crosswind component. The greater the crosswind component, the more difficult it is to prevent
weathervaning, especially with a conventional-gear airplane.
Maintaining control on the ground is a critical part of the after-landing roll because of the weathervaning effect of the wind on the
airplane. Additionally, tire side load from runway contact while drifting may generate a "roll-over" in a tricycle-geared airplane. This
occurs when one main wheel lifts up off the ground and the airplane tips forward along the axis between the nose-wheel and the main
wheel still on the ground. A roll-over could cause one wingtip or the prop to contact the ground. The basic factors involved are cornering
angle and side load.
Cornering angle is the angular difference between the heading of a tire and its path. Whenever a load-bearing tire’s path and heading
diverge, a side load is created. It is accompanied by tire distortion. Although side load differs in varying tires and air pressures, it is
completely independent of speed, and through a considerable range, is directly proportional to the cornering angle and the weight
supported by the tire. As little as 10° of cornering angle creates a side load equal to half the supported weight; after 20°, the side load
does not increase with increasing cornering angle. For each high-wing, tricycle-geared airplane, there is a cornering angle at which
roll-over is inevitable. At lesser angles, the roll-over may be avoided by use of ailerons, rudder, or steerable nose-wheel, but not brakes.
While the airplane is decelerating during the after-landing roll, more and more aileron is applied to keep the upwind wing from rising.
Since the airplane is slowing down, there is less airflow around the ailerons and they become less effective. At the same time, the relative
wind becomes more of a crosswind and exerts a greater lifting force on the upwind wing. When the airplane is coming to a stop, the
aileron control should be held fully toward the wind.
Maximum Safe Crosswind Velocities
Takeoffs and landings in certain crosswind conditions are inadvisable or even dangerous. [Figure 9-18] If the crosswind is great enough
to warrant an extreme drift correction, a hazardous landing condition may result. Therefore, the takeoff and landing capabilities with
respect to the reported surface wind conditions and the available landing directions should be considered.
Figure 9-18. Crosswind chart.
Before an airplane is type certificated by the Federal Aviation Administration (FAA), it is flight tested to ensure it meets certain
requirements. Among these is the demonstration of being satisfactorily controllable with no exceptional degree of skill or alertness on
the part of the pilot in 90° crosswinds up to a velocity equal to 0.2 VSO. This means a wind speed of two-tenths of the airplane’s stalling
speed with power off and in landing configuration. The demonstrated crosswind velocity is included on a placard in airplanes certificated
after May 3, 1962.
The headwind component and the crosswind component for a given situation is determined by reference to a crosswind component chart.
[Figure 9-19] It is imperative that pilots determine the maximum crosswind component of each airplane they fly and avoid operations
in wind conditions that exceed the capability of the airplane.
Figure 9-19. Crosswind component chart.
Common Errors
Common errors in the performance of crosswind approaches and landings are:
1. Attempted landing in crosswinds that exceed the airplane’s maximum demonstrated crosswind component.
2. Undershooting or overshooting the turn from base leg to final approach.
3. Inadequate compensation for wind drift on final approach.
4. Unstable approach.
5. Excessive sink rate or too low an airspeed from increased drag and reduced vertical lift during sideslip.
6. Failure to touch down with the longitudinal axis aligned with the runway.
7. Touching down while drifting.
8. Excessive airspeed on touchdown.
9. Failure to apply appropriate flight control inputs during rollout.
10. Failure to maintain direction control on rollout.
11. Excessive braking.
12. Loss of aircraft control.
Turbulent Air Approach and Landing
For landing in turbulent conditions, the pilot should use a power-on approach at an airspeed slightly above the normal approach speed.
This provides for more positive control of the airplane when strong horizontal wind gusts, or up and down drafts, are experienced. Like
other power-on approaches, a coordinated combination of both pitch and power adjustments is usually required. The proper approach
attitude and airspeed require a minimum round out and should result in little or no floating during the landing.
To maintain control during an approach in turbulent air with gusty crosswind, the pilot should use partial wing flaps. With less than full
flaps, the airplane is in a higher pitch attitude. Thus, it requires less of a pitch change to establish the landing attitude and touchdown at
a higher airspeed to ensure more positive control.
Pilots often use the normal approach speed plus one-half of the wind gust factors in turbulent conditions. If the normal speed is 70 knots,
and the wind gusts are 15 knots, an increase of airspeed to 77 knots is appropriate. In any case, the airspeed and the flap setting should
conform to airplane manufacturer's recommendations in the AFM/POH.
Use an adequate amount of power to maintain the proper airspeed and descent path throughout the approach, and retard the throttle to
idling position only after the main wheels contact the landing surface. Care should be exercised in closing the throttle before the pilot is
ready for touchdown. In turbulent conditions, the sudden or premature closing of the throttle may cause a sudden increase in the descent
rate, resulting in a hard landing.
When landing from power approaches in turbulence, the touchdown is made with the airplane in approximately level flight attitude. The
pitch attitude at touchdown would be only enough to prevent the nose-wheel from contacting the surface before the main wheels have
touched the surface. After touchdown, the pilot should avoid the tendency to apply forward pressure on the yoke, as this may result in
wheelbarrowing and possible loss of control. The pilot should allow the airplane to decelerate normally, assisted by careful use of wheel
brakes and avoid heavy braking until the wings are devoid of lift and the airplane’s full weight is resting on the landing gear.
Short-Field Approach and Landing
Short-field approaches and landings require the use of procedures for approaches and landings at fields with a relatively short landing
area or where an approach is made over obstacles that limit the available landing area. [Figure 9-20 and Figure 9-21] This low-speed
type of power-on approach is closely related to the performance of flight near minimum controllable airspeeds.
Figure 9-20. Landing over an obstacle.
Figure 9-21. Landing on a short field.
To land within a short field or a confined area, the pilot needs to have precise, positive control of the rate of descent and airspeed, and
fly an approach that clears any obstacles, results in little or no floating during the round out, and permits the airplane to be stopped in
the shortest possible distance. When safety and conditions permit, a wider-than-normal pattern with a longer final approach may be
used. This allows the pilot ample opportunity to adjust and stabilize the descent angle after the airplane is configured and trimmed. A
stabilized approach is essential.
The procedures for landing on a short field or for landing approaches over obstacles as recommended in the AFM/POH should be used.
[Figure 9-22 and Figure 9-23] These procedures generally involve a final approach started from an altitude of at least 500 feet higher
than the touchdown area and the use of full flaps at an appropriate point during the final approach. For many general aviation airplanes
this means flying a stabilized final approach with the flap setting that precedes full flaps. When the field is made, the pilot should
extend full flaps and lower the nose in order to maintain airspeed and keep the aiming point stationary in the windscreen. When over
the obstacle, the pilot may reduce power slightly. Ideally, if full flaps are extended at the correct point, the pilot will be in a position to
slowly reduce power. When no manufacturer’s recommended approach speed is available, a speed of not more than 1.3 VSO is used. In
gusty air, no more than one-half the gust factor is added. An excessive amount of airspeed could result in a touchdown too far from the
runway threshold or an after-landing roll that exceeds the available landing area. When obstacles are present, a slightly steeper approach
angle places the touchdown closer to the obstacle, which gives the pilot more room to stop.
Figure 9-22. Stabilized approach.
Figure 9-23. Unstabilized approach.
After the landing gear has been extended, if applicable, or when beginning a suitable final approach, the pilot simultaneously adjusts the
power and the pitch attitude to establish and maintain the proper descent angle and airspeed. During a stabilized approach, small changes
in the airplane’s pitch attitude and power setting are needed when making corrections to the angle of descent and airspeed.
The short-field approach and landing is an accuracy approach to an aiming point. The procedures previously outlined in the section on
the stabilized approach concept are used. If it appears that the obstacle clearance is excessive and touchdown occurs well beyond the
desired aiming point, leaving insufficient room to stop, power is reduced while lowering the pitch attitude to steepen the descent path
and increase the rate of descent. If it appears that the descent angle does not ensure safe clearance of obstacles, power is increased while
simultaneously raising the pitch attitude to shallow the descent path and decrease the rate of descent. Care should be taken to avoid
excessively low airspeeds. When operating at high AOAs and low airspeeds, an increase in pitch attitude increases the rate of descent.
When there is doubt regarding the outcome of the approach, the pilot should execute a go-around, evaluate the situation, and decide
whether to make another approach or divert to a more suitable landing area.
Because the final approach over obstacles is made at a relatively steep approach angle and close to the airplane’s stalling speed, the
initiation of the round out or flare needs to be judged accurately to avoid flying into the ground or stalling prematurely and sinking
rapidly. A lack of floating during the flare with sufficient control to touch down properly is verification that the approach speed was
correct.
Touchdown should occur at the minimum controllable airspeed with the airplane in approximately the pitch attitude that results in a
power-off stall when the throttle is closed. Care should be exercised to avoid closing the throttle too rapidly, as closing the throttle may
result in an immediate increase in the rate of descent and a hard landing. Note that a small amount of power provides more airflow over
the elevator giving it more authority at low airspeeds to enable the pilot to flare. There is a risk that low airspeed and a windmilling
propeller blocking airflow over the elevator may make it difficult to flare.
Upon touchdown, the airplane is held in this positive pitch attitude as long as the elevators remain effective and if recommended by the
manufacturer. This provides aerodynamic braking to assist in deceleration. However, immediately upon touchdown of the nose-wheel,
maximum braking is applied to minimize the after-landing roll. For most airplanes, aerodynamic drag is the single biggest factor in
slowing the aircraft in the first quarter of its speed decay. Brakes become increasingly effective as airspeed and lift decrease. The pilot
increases braking effectiveness by holding the wheel or stick full back while smoothly applying brakes. Back pressure is needed because
the airplane tends to lean forward with heavy braking. Best braking results are always achieved with the wheels in an “incipient skid
condition.” That means a little more brake pressure would lock up the wheels entirely. In an incipient skid, the wheels are turning, but
with great reluctance. If the wheels lock, braking effectiveness drops dramatically in a skid and the tires could be damaged. The airplane
is normally stopped within the shortest possible distance consistent with safety and controllability. If the proper approach speed has been
maintained, resulting in minimum float during the round out and the touchdown made at minimum control speed, excessive braking
should not be needed.
Common Errors
Common errors in the performance of short-field approaches and landings are:
1. A final approach that necessitates an overly steep approach and high sink rate.
2. Unstable approach.
3. Undue delay in initiating glide path corrections.
4. Too low an airspeed on final resulting in inability to flare properly and landing hard.
5. Too high an airspeed resulting in floating on round out.
6. Prematurely reducing power to idle on round out resulting in hard landing.
7. Touchdown with excessive airspeed.
8. Excessive and/or unnecessary braking after touchdown.
9. Failure to maintain directional control.
10. Failure to recognize and abort a poor approach that cannot be completed safely.
Soft-Field Approach and Landing
Landing on fields that are rough or have soft surfaces, such as snow, sand, mud, or tall grass, requires unique procedures. When landing
on such surfaces, the objective is to touch down as smoothly as possible and at the slowest possible landing speed. A pilot needs to control
the airplane in a manner that the wings support the weight of the airplane as long as practical to minimize stresses imposed on the landing
gear by a rough surface or to prevent sinking into a soft surface.
The approach for the soft-field landing is similar to the normal approach used for operating into long, firm landing areas. The major
difference between the two is that a degree of power is used throughout the level-off and touchdown for the soft-field landing. This allows
the airspeed to slowly dissipate while the airplane is flown 1 to 2 feet off the surface in ground effect. When the wheels first touch the
ground, the wings continue to support much of the weight of the airplane. [Figure 9-24] This technique minimizes the nose-over forces
that suddenly affect the airplane at the moment of touchdown.
Figure 9-24. Soft/rough field approach and landing.
The use of flaps during soft-field landings aids in touching down at minimum speed and is recommended whenever practical. In low-wing
airplanes, the flaps may suffer damage from mud, stones, or slush thrown up by the wheels. If flaps are used, it is generally inadvisable
to retract them during the after-landing roll because the need for flap retraction is less important than the need for total concentration on
maintaining full control of the airplane.
The final-approach airspeed used for short-field landings is equally appropriate to soft-field landings. The use of higher approach speeds
may result in excessive float in ground effect, and floating makes a smooth, controlled touchdown even more difficult. There is no reason
for a steep angle of descent unless obstacles are present in the approach path.
Touchdown on a soft or rough field is made at the lowest possible airspeed with the airplane in a nose-high pitch attitude. In nose-wheel
type airplanes, after the main wheels touch the surface, the pilot should hold sufficient back-elevator pressure to keep the nose-wheel off
the surface. Using back-elevator pressure and engine power, the pilot can control the rate at which the weight of the airplane is transferred
from the wings to the wheels.
Field conditions may warrant that the pilot maintain a flight condition in which the main wheels are just touching the surface but the
weight of the airplane is still being supported by the wings until a suitable taxi surface is reached. At any time during this transition
phase, before the weight of the airplane is being supported by the wheels, and before the nose-wheel is on the surface, the ability is
retained to apply full power and perform a safe takeoff (obstacle clearance and field length permitting) should the pilot elect to abandon
the landing. Once committed to a landing, the pilot should gently lower the nose-wheel to the surface. A slight addition of power usually
aids in easing the nose-wheel down.
The use of brakes on a soft field is not needed and should be avoided as this may tend to impose a heavy load on the nose-gear due to
premature or hard contact with the landing surface, causing the nose-wheel to dig in. The soft or rough surface itself provides sufficient
reduction in the airplane’s forward speed. Often upon landing on a very soft field, an increase in power may be needed to keep the
airplane moving and from becoming stuck in the soft surface.
Common Errors
Common errors in the performance of soft-field approaches and landings are:
1. Excessive descent rate on final approach.
2. Excessive airspeed on final approach.
3. Unstable approach.
4. Round out too high above the runway surface.
5. Poor power management during round out and touchdown.
6. Hard touchdown.
7. Inadequate control of the airplane weight transfer from wings to wheels after touchdown.
8. Allowing the nose-wheel to “fall” to the runway after touchdown rather than controlling its descent.
Power-Off Accuracy Approaches
Power-off accuracy approaches and landings involve gliding to a touchdown at a given point (or within a specified distance beyond
that point), while using a specific pattern and with the engine idling. The objective is to instill in the pilot the judgment and procedures
necessary for accurately flying the airplane, without power, to a safe landing.
The ability to estimate the distance an airplane glides to a landing is the real basis of all power-off accuracy approaches and landings.
The distance to be covered largely determines the amount of maneuvering needed to complete an approach from a given altitude. While
developing the pilot's ability to estimate gliding distance, power-off accuracy approaches call upon the pilot to use a variety of techniques
to set and maintain an appropriate glide angle and airspeed to the aiming point.
With experience and practice, altitudes up to approximately 1,000 feet can be estimated with fair accuracy; while above this level the
accuracy in judgment of height above the ground decreases, since all features tend to merge. The best aid in perfecting the ability to
judge height above this altitude is through the indications of the altimeter and associating them with the general appearance of the earth.
The judgment of altitude in feet, hundreds of feet, or thousands of feet is not as important as the ability to estimate gliding angle and
its resultant distance. Regardless of altitude, a pilot who knows the normal glide angle of the airplane can estimate, with reasonable
accuracy, the approximate spot along a given ground path at which the airplane will land. A pilot who has the ability to accurately
estimate altitude, can also judge how much maneuvering is possible and safe during the glide, which is important to the choice of landing
areas in an actual emergency.
The objective of a good final approach is to descend at an angle that permits the airplane to reach the desired aiming point at an airspeed
that results in a predictable float where touchdown occurs on or within a specified distance beyond a designated point. To accomplish
this, it is essential that both the descent angle and the airspeed be accurately controlled.
Unlike a normal approach when the power setting is variable, on a power-off approach the power is fixed at the idle setting. Pitch attitude
is adjusted to control the airspeed. This also changes the glide or descent angle. If an airplane is on approach with an airspeed higher
than best glide, pitching down will increase the airspeed and steepen the descent angle, while pitching up will reduce the airspeed and
shallow the descent angle. Conversely, if the airspeed is below best glide, then pitching down will increase the airspeed and shallow the
descent angle, while pitching up will reduce the airspeed and will greatly steepen the descent angle. If the airspeed is too high, the pilot