11 - Descent and Landing Performance

Summary

Overview

The descent deals with that segment of the flight when the airplane decreases its flight altitude in a controlled mode. Landing still requires good pilot skills, which are best appreciated in bad weather conditions. The descent can be a large portion of the stage length, reaching in excess of 100 n-miles. Several distinct phases are identified. We will consider separately the phase of en-route descent down to 1,500 feet altitude above the airfield (§ 11.1) and the final approach down to ˜50 feet above the airfield (§ 11.2).We also discuss two unconventional flight procedures: the continuous descent approach (§ 11.3), which has some advantages in terms of fuel consumption and noise emissions, and the steep-descent approach, which is a more complex manoeuvre (§ 11.4). We analyse the case of airplanes placed on holding stacks (§ 11.6) and optimal performance issues. Landing consists of an airborne phase and a landing run (§ 11.7). Effects of side gusts are considered, including crab landing and wing strike. This chapter ends with considerations of go-around trajectories, which are associated to aborted landing (§ 11.8).

KEY CONCEPTS: En-Route Descent, Continuous Descent Approach, Steep Descent, Unpowered Descent, Holding Procedure, Landing Performance, Crab Landing, Go-Around.

En-Route Descent

The aircraft starts descending from its cruise altitude well ahead of its destination. The flight computer will indicate the distance to the airfield and the estimated en-route descent, that is, the distance and time to landing, based on a number of factors, including speed, altitude and winds.