weather

rain. fog. frost.

Turbulence and good surface visibility. Turbulence and poor surface visibility. Nimbostratus clouds and good surface visibility.

Propeller efficiency is decreased. Density altitude does not affect propeller efficiency. Propeller efficiency is increased.

Nimbostratus. Cumulonimbus. Towering cumulus.

Turbulent air. Showery precipitation. Poor surface visibility.

Efficiency is reduced because the propeller exerts less force at high density altitudes than at low density altitudes. Efficiency is reduced due to the increased force of the propeller in the thinner air. Efficiency is increased due to less friction ...

An air mass moving inland from the coast in winter. A warm, moist air mass on the windward side of mountains. A light breeze blowing colder air out to sea.