Page 517 - PPL-engelsk 2025

Principles of flight

5.10.4.3 Coordinated turn

When we turn, we can use the turn indicator with the

balance indicator to see whether the turn has been

executed in a coordinated manner.

In a coordinated turn, the level ball must remain in the

middle of the balance indicator.

If the level ball rolls out to the side, the turn has been executed with too much

or too little amount of bank. To get the ball back in place, apply a little rudder.
In the picture above, this means that we need to use the left pedal because the

ball is to the left of center.

We cannot see by how many degrees the aircraft is banking, but we can see that

in 2 minutes we will turn 360 degrees.

Instruments are primarily used for procedural turns.

5.10.4.4 Speed and turn rate vs. turn radius

The figure below shows the relationship between the aircraft's speed and turn

rate as well as the turn radius for a turn with 30° bank.

If the speed is doubled, the radius becomes approx. 4 times larger.

o
The illustration here shows 30 bank at 100, 150 and 200 kts. We can see the
change in radius and rate (rate of roll), i.e. how quickly the aircraft changes its

bank.

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 517