Page 476 - PPL-engelsk 2025
P. 476
Principles of flight
An aircraft is “clean” when none of these are
in use.
The figure here shows the
dependence of lift on the angle of
attack for a clean wing, a wing with
lowered flaps, and a wing with open
slots.
Distance A is the increase in lift that
is obtained by using flaps.
Distance B is the increase in the critical angle of attack by opening slots.
Earlier you could read that with flaps, stall occurs at a lower angle of attack.
Stall with slots occurs at a higher angle of attack.
The use of slots reduces the formation of turbulent airflow along the wing at
high angles of attack.
The figures here show the principle.
The wing at the top has a leading edge slot
and the airflow is restored.
The wing at the bottom has closed slot and is
stalled.
Back to table of contents
5.5 The 4 forces during flight (Flyveprincipper 3 - 2 videoer)
During level flight at constant speed, the following forces act on the aircraft:
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 476
