34 with: constant airspeed constant power No flaps;  flatter descent angle Half flaps F ull flaps;  steeper descent angle Figure 8-4.  Effect of flaps on the approach angle. through judgment of the descent angle. If it appears that the  airplane is going to overshoot the desired landing spot, more  flaps are used, if not fully extended, or the power reduced  further and the pitch attitude lowered. This results in a steeper  approach. If the desired landing spot is being undershot and a  shallower approach is needed, both power and pitch attitude  are increased to readjust the descent angle. Never retract  the flaps to correct for undershooting since that suddenly  decreases the lift and causes the airplane to sink rapidly. Speed blurs objects at close range. For example, most  everyone has noted this in an automobile moving at high  speed. Nearby objects seem to merge together in a blur,  while objects farther away stand out clearly. The driver  subconsciously focuses the eyes sufficiently far ahead of the  automobile to see objects distinctly. requires that the vision be focused properly in order that the  important objects stand out as clearly as possible. The distance at which the pilot’s vision is focused should be  proportionate to the speed at which the airplane is traveling  over the ground. Thus, as speed is reduced during the round  out, the distance ahead of the airplane at which it is possible  to focus is brought closer accordingly. The airplane must be re-trimmed on the final approach to  compensate for the change in aerodynamic forces. With  the reduced power and with a slower airspeed, the airflow  produces less lift on the wings and less downward force on  the horizontal stabilizer resulting in a significant nose-down  tendency. The elevator must then be trimmed more nose-up. The round out, touchdown, and landing roll are much easier  to accomplish when they are preceded by a proper final  approach consisting of precise control of airspeed, attitude,  power, and drag resulting in a stabilized descent angle. If the pilot attempts to focus on a reference that is too close  or looks directly down, the reference becomes blurred,  [Figure 8-5]  and the reaction is either too abrupt or too late.  In this case, the pilot’s tendency is to over-control, round  out high, and make full-stall, drop-in landings. If the pilot  focuses too far ahead, accuracy in judging the closeness of  the ground is lost and the consequent reaction is too slow  since there does not appear to be a necessity for action. This  results in the airplane flying into the ground nose first. The  change of visual focus from a long distance to a short distance  requires a definite time interval and, even though the time  is brief, the airplane’s speed during this interval is such that  the airplane travels an appreciable distance, both forward  and downward toward the ground. During the approach, round out, and touchdown; vision is  of prime importance. To provide a wide scope of vision and  to foster good judgment of height and movement, the pilot’s  head should assume a natural, straight-ahead position. Visual  focus is not fixed on any one side or any one spot ahead of  the airplane. Instead, it is changed slowly from a point just  over the airplane’s nose to the desired touchdown zone and  back again. This is done while maintaining a deliberate  awareness of distance from either side of the runway using  your peripheral field of vision. Accurate estimation of distance is, besides being a matter  of practice, dependent upon how clearly objects are seen. It  If the focus is changed gradually, being brought progressively  closer as speed is reduced, the time interval and the pilot’s  reaction are reduced and the whole landing process smoothed out. 8-5 Estimating Height and Movement