PLT118: Aircraft Instruments
What code PLT118 covers, why the FAA tests it, and how to study Aircraft Instruments before your checkride.
Recall aircraft instruments - gyroscopic
What this means for your checkride
The gyroscopic instruments, the attitude indicator, heading indicator, and turn coordinator, use spinning gyros driven by vacuum or electricity to hold a stable reference. They give attitude and turn information the pressure instruments cannot.
Gyroscopic instruments are central to attitude flying and to recognizing instrument failures, so the FAA tests how they are powered and how they fail.
Pilots assume all three fail together. A vacuum failure takes the vacuum-driven instruments while the electric turn coordinator keeps working, and vice versa.
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.