Page 637 - PPL-engelsk 2025

Flight performance and planning

7.6 Power and thrust

There are 2 different types of forces:

- power

- thrust

7.6.1 Power

Power can be expressed as the weight of the object being moved times the

acceleration, which is the change in velocity per unit time.

Power = mass x acceleration

Where the least power is required is where there is the least drag, and there we

have the best glide speed.

If you observe the figure here, which shows the principles, you can see that the

higher the speed the aircraft is moving, the higher the power required.

You can also see that where the distance to the curve is greatest, which shows

drag or force required to fly a certain speed, we find Vy, which is the speed of best

climb (in feet per minute - there is “time” related when we talk about power).

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 637