Approach and landing

The landing is the most difficult task the pilot has to undertake. It requires an accurate approach to position the aircraft correctly in relation to the runway, together with precise control during touch-down which may be complicated by winds blowing across the flightpath.

Figure 13.6 shows the stages from initial approach to touch-down. Some way out from the runway the aircraft speed is reduced and high lift devices extended to reduce the minimum flying speed. A typical landing configuration is shown in Fig. 13.7. Comparing this with the corresponding take-off con­figuration it can be seen that a lot more trailing-edge flap is used because extra drag is, of course, a positive advantage during landing, both from the point of view of the final deceleration of the aircraft and because a high drag configura­tion leads to easier speed control.

At the start of the landing manoeuvre the aircraft is aligned with the runway and put into a steady descent along the ‘glide path’. As the runway threshold is reached the angle of attack is increased so that the rate of descent is reduced and the aircraft is ‘flared’ so that it flies just above and nearly parallel to the runway until the touchdown point is reached. At this point the aim is to stop as quickly and safely as possible. In order to provide aerodynamic braking and

to sit the aircraft firmly on the runway ‘lift dumpers’, or spoilers, may be used Fig. 13.7. Jet aircraft frequently use thrust reversers (Fig. 6.32) to provide further deceleration and to relieve the wheel brake requirement. Some military aircraft even resort to the use of a braking parachute to shorten the landing run.