PLT128: Aircraft Performance
What code PLT128 covers, why the FAA tests it, and how to study Aircraft Performance before your checkride.
Recall aircraft performance - effects of icing
What this means for your checkride
Structural icing changes the shape of the wing, adds weight, and increases drag, all of which cut lift and raise the stall speed. Even a thin layer of frost or rime can disrupt the airflow enough to prevent takeoff or degrade climb, and ice on the airframe can block the pitot system and control surfaces.
Icing is a leading weather hazard, so the FAA tests whether you understand how it degrades performance and why you must remove all frost and ice before flight.
A dangerous belief is that a little frost is cosmetic. Frost roughens the wing surface, disrupts airflow, and can prevent the airplane from becoming airborne, so it must be removed, not polished smooth.
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.