Low Final Approach
When the base leg is too low, insufficient power is used, or the velocity of the wind is misjudged, sufficient altitude may be lost, which causes the aircraft to be well below the proper final approach path. In such a situation, the pilot would need to apply considerable power to maintain or gain altitude as required to fly the aircraft (at an excessively low altitude) up to the runway threshold. When the proper approach path has been intercepted, the correct approach attitude should be reestablished, the power reduced, and a stabilized approach maintained. [Figure 11-36]
Do not increase the pitch attitude without increasing the power since the aircraft decelerates rapidly and may approach the critical AOA and stall. If there is any doubt about the approach being safely completed, it is advisable to execute an immediate go-around.
High Final Approach
When the final approach is too high, perform a steep approach as required for the height above the landing spot. Refer to the steep approach section earlier in this chapter.
Slow Final Approach
When the aircraft is flown at slower-than-normal airspeed on the final approach, pilot determination of the rate of sink (descent) and the height of roundout is difficult. During an excessively slow approach, the wing is operating near the critical AOA and, depending on the pitch attitude changes and control usage, the aircraft may stall or sink rapidly and contact the ground with a hard impact.
Whenever a low-speed approach is noted, the pilot should apply power and accelerate the aircraft to reduce the sink rate to prevent a stall. This should be done while still at a high enough altitude to reestablish the correct approach airspeed and attitude. If too slow and too low, it is best to execute a go-around.
Use of Power
Power can be used if required during the approach and roundout to compensate for errors in judgment. The pilot should be ready to use the foot throttle while managing the energy throughout the landing, utilizing energy management procedures for the current landing conditions. Power can be added to reduce the descent rate if needed; thus, the descent can be slowed to an acceptable rate. After the aircraft has touched down, it is necessary to close the throttle to remove additional thrust and lift allowing the aircraft to stay on the ground.
Sometimes when the aircraft appears to stop moving downward temporarily, the roundout has been made too rapidly and the aircraft is flying level, too high and too slow above the runway. Continuing the roundout would further reduce the airspeed, resulting in an increase in AOA to the critical angle. This would result in the aircraft stalling and dropping hard onto the runway. To prevent the hard drop, pitch attitude should be reduced slightly to increase speed to approach speed while throttle is added to maintain altitude. After speed has been increased and altitude maintained, the throttle and speed can both be reduced smoothly and gradually for a gradual descent with a normal roundout and touchdown.
Although speed is needed after the high roundout is noticed in order to be corrected, the power application must be enough to remain level and not initially descend as the speed is increased. Energy management proficiency is critical. If too little throttle is added, the momentary decrease in lift that would result from lowering the nose and decreasing the AOA may be so great that the aircraft might contact the ground with the nosewheel first, which could then collapse. As for all landing maneuvers that are questionable and the outcome is uncertain, it is recommended that a go-around be executed.
Late or Rapid Roundout
Starting the roundout too late or pushing the control forward too rapidly to prevent the aircraft from touching down prematurely balloons the aircraft up above the runway. Suddenly increasing the AOA and stalling the aircraft during a roundout is a dangerous situation since it may cause the aircraft to land extremely hard on the main landing gear and then bounce back into the air.
Recovery from this situation requires prompt and positive application of power and a lowering of the nose to increase speed prior to occurrence of the stall. This may be followed by a normal landing, if suffi cient runway is available, similar to the high roundout discussed above—otherwise the pilot should immediately execute a go-around.
Floating During Roundout
If the airspeed on final approach is excessive, it usually results in the aircraft fl oating in ground effect. This is not a problem if there is plenty of runway and if the pilot floats with the wheels just inches above the surface. Simply maintain this position inches above the runway, slowly rounding out as required until the speed bleeds off for a normal touchdown. If conditions are turbulent, the nose can be lowered gradually and the aircraft flown onto the ground, as discussed earlier in the landing in turbulence procedures.
If the aircraft is well past the desired landing point and the available runway is insufficient, perform a go-around immediately.
Ballooning During Roundout
If the pilot misjudges the rate of sink during a landing and thinks the aircraft is descending faster than it should, there is a tendency to increase the pitch attitude and AOA too rapidly. This not only stops the descent, but actually starts the aircraft climbing. This climbing during the roundout is known as ballooning. Ballooning can be dangerous because the height above the ground is increasing and the aircraft may be rapidly approaching a stall. The altitude gained in each instance depends on the airspeed or the speed with which the pitch attitude is increased.
When ballooning is slight, the nose should be lowered to increase speed and return to a gradual descent. Recovery procedures are similar to those for rounding out too high: lowering the nose slightly and increasing the throttle to remain level. Then, the pilot gradually reduces throttle and speed for a controlled descent rate with the throttle at idle during touchdown.
When ballooning is excessive, it is best to execute a go-around immediately; do not attempt to salvage the landing. Full power must be applied and the nose lowered before the aircraft enters a stalled condition.
The pilot must be extremely cautious of ballooning when there is a crosswind present because the crosswind correction may be inadvertently released or it may become inadequate. Because of the lower airspeed after ballooning, the crosswind affects the aircraft more. Consequently, crabbing has to be increased to compensate for the increased drift. It is imperative that the pilot makes certain that directional control is maintained. If there is any doubt, or the aircraft starts to drift, execute a go-around.