Page 498 - PPL-engelsk 2025

Principles of flight

5.8.1.1 Maximum maneuvering speed

One speed is not shown on the airspeed indicator. It is the maximum

maneuvering speed (Va), where you can use full deflection of the control wheel

in severe turbulence without exceeding the load factor (3.8G for small aircraft).

(in one direction at the time)

Va is given in the aircraft manual.

If you fly at speeds below Va, the aircraft will stall before it becomes overloaded.

So what we can use Va for is that when we fly in severe turbulence, we reduce

the speed to Va, to avoid overloading the aircraft.

Va must be at least the stall speed *√Limit load factor .

If the limit load factor is 3.8 G, Va must be at least 1.95 times the stall speed. If

there is severe turbulence, reduce the speed to just under 2 x the stall speed.

Va is usually stated at full weight, but can be calculated using the following

formula for anything other than full weight:

Va new weight = √ * Va full weight

Example:

Va is stated at 120Kt at 2300 lbs, actual flight weight is 2000 lbs.

2000
What is Va at 2000 lbs? √ x 120 = 111.9 Kt
2300

Many believe that the less weight the aircraft has, the faster the aircraft can fly

before it is overloaded.

Statically, the wings do not suffer overload either, but if the aircraft is exposed

to, for example, 4.5 G, then it weighs 4.5 times as much.

However, it is not certain that, for example, the engine foundation can withstand

an engine that weighs 4.5 times as much.
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 498