PLT168: Angle of Attack
What code PLT168 covers, why the FAA tests it, and how to study Angle of Attack before your checkride.
Recall angle of attack - characteristics / forces / principles
What this means for your checkride
Angle of attack is the angle between the wing's chord line and the oncoming air. Lift increases with angle of attack up to the critical angle; beyond it the airflow separates and the wing stalls, whatever the airspeed or attitude.
A wing stalls at its critical angle of attack, not a fixed speed, so the FAA tests this to be sure you understand why a stall can happen at any airspeed and attitude.
The common error is that a stall is about slow speed. It is about exceeding the critical angle of attack, which can happen fast, in a turn, or nose-low.
Where to study it
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.