FAA Flight Instructor Airplane (FIA)Aerodynamics and Principles of FlightMedium
A pilot enters a turn using coordinated aileron and rudder inputs. Without rudder input, the airplane would initially yaw toward the outside of the turn due to greater drag on the raised aileron's wing. This tendency is known as:
- Aadverse yaw
- BP-factor
- Cgyroscopic precession
- Dspiral instability
Show answer & explanationAnswer & explanation
Correct answer: A. adverse yaw
Adverse yaw occurs because the aileron deflected downward (on the rising wing) produces more induced drag than the aileron deflected upward (on the lowering wing), yawing the nose toward the outside of the turn. Rudder is used to counteract this.
Why the other options are wrong
- B. P-factor is caused by asymmetric propeller blade thrust at high AOA, unrelated to aileron drag.
- C. Gyroscopic precession relates to propeller forces, not aileron deflection.
- D. Spiral instability is a longitudinal-directional coupling issue occurring over time, not an immediate turn-entry effect.
Adverse Yaw
The tendency of an airplane's nose to yaw toward the outside of a turn due to greater induced drag on the wing with the down-deflected aileron.
- Caused by differential aileron drag
- Corrected with coordinated rudder input
- More pronounced at low airspeed and large aileron deflections
- Frise-type ailerons help reduce adverse yaw
Memory trick: 'Adverse' = drag drags nose the wrong way