Page 695 - PPL-engelsk 2025

Aircraft general knowledge

8.3.7.2 Static and dynamic balancing

It is important that all control surfaces are balanced both statically and

dynamically. Static to avoid vibrations (flutter) in the controls. Dynamic to ease

control deflection.

The principle of dynamic balancing is shown here.

Here, part of the rudder surface is placed in front

of the hinge line/axis of rotation.

This makes the operation of the rudder easier so that not as much pull is required
in the control lines.

The illustration here shows a
dynamic/static balancing. Part of the

rudder surface is also here in front of the

rotation axis.

In this horn, as it is called, a lead

counterweight is placed, which pushes

the rudder surface's center of gravity onto the axis of rotation and ensures that
there is static balance.

8.3.7.3 Flaps

Flaps are mounted on the trailing edge of the aircraft's wings, inward towards
the body. The purpose of flaps is to increase the

aircraft's ability to make a slow approach.

Flaps can be activated with a selector or a lever.

Electrically activated flaps are operated with a switch,

possibly with a pre-selected flap position.

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 695