PLT520: Density Altitude
What code PLT520 covers, why the FAA tests it, and how to study Density Altitude before your checkride.
Calculate density altitude
What this means for your checkride
Density altitude is found by first determining pressure altitude, then correcting it for nonstandard temperature. High density altitude means thin air and reduced engine, propeller, and wing performance. High elevation, high temperature, and high humidity all raise density altitude.
Density altitude directly affects takeoff, climb, and landing performance, so pilots must know how to determine it and its effects.
Density altitude is not the same as the altimeter reading; hot, high, and humid conditions raise it well above the field elevation.
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.