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Principles of flight
5.3.7.1 Profile drag
The total form and friction drag of the wing is called profile drag. Profile drag
depends on:
- Speed
- Air density
- Front area
- Angle of attack
As the angle of attack increases, the front area increases, thus increasing drag.
Turbulent flow forms behind the profile and continued increases in angle of attack
will cause the wing to stall.
When the angle of attack exceeds 10 degrees, it has a significant effect on drag.
At low flight speeds, induced drag is greater than profile drag. As speed increases,
profile drag becomes the dominant factor.
5.3.7.2 Induced drag and wingtip vortices
When a wing generates lift, the overpressure on the underside of the wing tends
to equalize with the low pressure on the upper side.
This partial equalization results in a
loss of performance.
This loss is called induced drag.
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 458
