What are characteristics of a moist, unstable air mass?
A. Turbulence and showery precipitation.
B. Poor visibility and smooth air.
C. Haze and smoke.
Answer: A. Turbulence and showery precipitation.
Unstable air rises readily, building cumulus clouds that bring turbulence and showers. Visibility is usually good outside the showers. Smooth air, haze and smoke are signs of stable air.
The FAA published this sample set in August 2021. Our answers were checked against the current regulations and against the testing-supplement figures in September 2026.