Page 655 - PPL-engelsk 2025

Flight performance and planning

An Indicated speed for “lift off” of 52 Kt is given. At 50 feet the speed should be

59 Kt.

We then need to look at the Pressure altitude (Pa) in the next column. This is the

height we have in relation to the 1013 hPa pressure surface.

Air pressure MSL is 1020 and compared to 1013 this is 7x30 feet = 210 feet higher

(since one hPa is equal to 30 feet). We are at a location that is 168 feet above

MSL. This means that we have conditions that are slightly better than standard.

In the figure for take-off distance (above), 2 circles show a take-off distance of
50 feet:

- at 20 degrees Celsius

- at 30 degrees Celsius

o
So, we find the value for 25 C in the middle. This is called interpolating and is
done by adding the numbers together and dividing by 2.

We get: (1575 + 1685)/2 = 1630 ft

We convert this to 500 meters on our computer.

7.9.2.11 Calculating landing distance

We also need to find a landing distance.

There is only one table

for full weight. In order

to use the figures here,

the condition is that we

use full flaps 40⁰C when
landing.

However, we do not want that, as we have plenty of runways available.

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 655