Landing performance
Navigation · Chapter 57 · DGCA CPL and ATPL
From 50 ft to a stop, inside only 60 % of the runway. Then add water.
Remember
- Screen 50 ft.
- Vat = 1.3 VS0.
- Jet 60 %, turboprop 70 %, wet ÷ 1.15.
- Distance goes with V².
- VP = 9 × √psi.
The landing
Landing distance starts in the air: from 50 ft over the threshold to a full stop.
Take-off’s screen is 35 ft. Landing’s is 50 ft, for all classes.
The speed over the threshold is at least 1.3 VS0: thirty per cent above the stall in landing configuration.
Vat = 1.3 VS0 or 1.23 VS1g
It floats about 300 m in the air, touches down, then the real work begins.
Spoilers kill the lift and put the weight on the wheels. Brakes take over. Reverse thrust helps while it is fast, but is cancelled at about 50 kt.
Stopped. Add the air part and the roll, and that is the landing distance required. It must fit inside LDA.
The safety margin
You may not plan to use the whole runway. A jet may plan to need only 60 % of LDA. A turboprop, 70 %.
On a wet runway, the LDA must be at least 115 % of what the dry figure needs. So divide by 1.15.
Jet 60 %, turboprop 70 %, wet ÷ 1.15.
Wet: required = dry figure ÷ 1.15
Maximum landing mass is the least of three: the structural limit, the runway limit, and the climb limit.
It may have to climb away. The rules check it can.
What lengthens it
This lesson is part of the Navigation plan. See plans
Water
This lesson is part of the Navigation plan. See plans