Adverse yaw
Adverse yaw: yaw against the pilot's intent. On turn entry, nose first swings away from the turn (TP 1102).
Cause (TP 1102):
- Rising wing (aileron down) makes more lift.
- More lift gives more induced drag there.
- Drag yaws nose toward the raised wing, away from the turn.
Worse with (TP 1102):
- Reduced airspeed
- Large, abrupt aileron input
Fix: rudder into the turn (TP 1102):
- Same direction as aileron, applied simultaneously.
- Pressure varies with abruptness of entry and aircraft type.
- Held only while ailerons are deflected.
- Used only if adverse yaw occurs.
- Modern designs nearly eliminate it, cutting rudder pressure on entry.
Design cures (TP 1102):
| Type | How it works |
|---|---|
| Differential ailerons | Down-going aileron deflects less than up-going. Up-going aileron (over descending wing) makes more drag to balance it |
| Frise ailerons | Up-going aileron hinged so leading edge dips into airflow under the wing, adding drag |
Trap: thinking yaw goes into the turn, or applying opposite rudder. Nose yaws away, so rudder goes with the turn. Excessive rudder on entry is one of the most common turn-entry faults (TP 1102). Do not rank it against wrong-direction rudder.
References
- TP 1102