PLT135: Pressurization
What code PLT135 covers, why the FAA tests it, and how to study Pressurization before your checkride.
Recall aircraft pressurization - system / operation
What this means for your checkride
A pressurization system pumps engine bleed air or compressor air into a sealed cabin so occupants breathe at a comfortable cabin altitude while the airplane flies much higher. An outflow valve regulates cabin pressure, and the system limits the pressure differential the fuselage can safely hold.
Pressurization enables high-altitude flight and carries its own emergencies, so the FAA tests how the system maintains cabin altitude and what a rapid decompression demands.
Pilots think cabin altitude equals airplane altitude. The system keeps cabin altitude far lower; a decompression makes cabin altitude climb toward the airplane's, which is why oxygen and a descent are immediate.
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.