Page 635 - PPL-engelsk 2025
P. 635
Flight performance and planning
7.5.1.3 Endurance (longest flight time)
The endurance of an aircraft is the maximum time the aircraft can stay in the air.
The speed to be used here is the speed that requires the least performance.
From this chart it appears that at point
3 we find the speed where the least
power is used – that is, where the
resistance is the least.
It is at this speed that the aircraft can
stay in the air for the longest time.
It would be sensible to use this speed
when holding.
It is an advantage to fly as low as possible and utilize the greater lifting capacity of
the air when flying a holding flight. The engine also has the best performance at
low altitude.
Usually, the aircraft manual contains charts that show the aircraft's performance.
7.5.1.4 Maximum range
To achieve the best range, one might think that one should use the speed where
one could achieve the greatest flight time in the air.
This is not the case.
In the picture, you can see that if you want to
achieve the greatest range, you should draw a
tangent to the red curve. It is shown in green.
Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 635
