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| CHAPTER 11. Approaches and Landings
Touchdown After a controlled roundout, the touchdown is the gentle settling of the aircraft onto the landing surface. For calm air conditions, the roundout can be made with the engine idling, and touchdown can be made at minimum controllable airspeed so that the aircraft touches down on the main gear at the approximate stalling speed. As the aircraft settles, the proper landing attitude is attained by application of whatever control bar forward pressure is necessary. In calm wind conditions, the goal is to round out smoothly and have the control bar touch the front tube as the back wheels touch the ground. [Figures 11-11 through 11-14] Once the rear wheel settles to the surface, the nosewheel settles to the ground. The control bar should be pulled all the way back to eliminate the possibility of lifting off the ground because of a wind gust. Pulling the nose down completely can also be used for aerodynamic braking if needed.
After-Landing Roll The landing process must never be considered complete until the aircraft decelerates to normal taxi speed during the landing roll or has been brought to a complete stop when clear of the landing area. Many accidents have occurred as a result of pilots abandoning their vigilance and positive control after getting the aircraft on the ground. The pilot must make only slight turns to maintain direction until the WSC has slowed to taxiing speed. An abrupt turn at high speed could possibly lift a rear wheel, roll the WSC over, or force the wingtip to the ground. The WSC must slow to taxing speed before before any sharp turn can be made to exit the runway. The brakes of an aircraft serve the same primary purpose as the brakes of an automobile—to reduce speed on the ground. Maximum brake effectiveness is just short of the skid point. If the brakes are applied so hard that skidding takes place, braking becomes ineffective. Skidding can be stopped by releasing the brake pressure. Also, braking effectiveness is not enhanced by alternately applying and reapplying brake pressure. The brakes should be applied fi rmly and smoothly as necessary. WSC aircraft have nosewheel or rear wheel braking systems. For nosewheel systems, if braking is required right away, the nose should be lowered so the nosewheel touches the ground and the brakes can be applied. The nose should be lowered for any aerodynamic braking at the higher speeds. Lowering the nose also provides greater force on the front wheel for superior braking effectiveness. Any skidding of the front wheel with braking causes the loss of directional control of the WSC aircraft and the skidding must be stopped by letting up on the brake. Skidding can be the greatest problem operating on slick surfaces such as wet grass. Rear wheel braking systems are heavier and more complex, but provide better braking force because there are two wheels instead of one and there is more weight on the rear wheels. Braking effectiveness should be evaluated by the pilot for each type of runway being used. If the available runway permits, the speed of the aircraft should be allowed to dissipate in a normal manner with minimum use of brakes. [Figure 11-15]
The control bar serves the same purpose on the ground as in the air—it changes the lift and drag components of the wings. During the after-landing roll, the control bar should be used to keep the wings level in much the same way it is used in fl ight. If a wing starts to rise, roll control should be applied to lower it. Procedures for crosswind conditions are explained further in the Crosswind Approach and Landing section of this chapter. |
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