PLT024: Adiabatic Process
What code PLT024 covers, why the FAA tests it, and how to study Adiabatic Process before your checkride.
Define atmospheric adiabatic process
What this means for your checkride
An adiabatic process is the temperature change of a parcel of air as it rises or sinks with no heat exchanged with the surrounding air: rising air expands and cools, sinking air compresses and warms. The rate this happens sets stability and where clouds form.
Adiabatic cooling drives cloud and thunderstorm development, so the FAA tests whether you understand how lifted air cools and when it becomes saturated.
Pilots think rising air cools by mixing with colder air aloft. It cools by expansion as pressure drops, which is why the temperature and dewpoint spread predicts the cloud base.
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.