PLT347: Critical Engine
What code PLT347 covers, why the FAA tests it, and how to study Critical Engine before your checkride.
Recall principles of flight - critical engine
What this means for your checkride
On a conventional twin, the critical engine is the one whose failure has the most adverse effect on directional control. Published VMC is determined with the critical engine inoperative. With both engines rotating clockwise as viewed from the pilot's seat, the left engine is the critical engine.
Losing the critical engine produces the greatest yaw and control challenge, so pilots must know which engine that is and how it drives minimum control speed.
Students often assume both engines are equal; the descending propeller blade's asymmetric thrust makes one engine more critical than the other.
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.