Weather Quiz

Two conditions are necessary for structural icing in flight: 1. The aircraft must be flying through visible water such as rain or cloud droplets, and 2. The temperature at the point where the moisture strikes the aircraft must be 0 degrees C (32 degrees F) or colder.

A condition favorable for rapid accumulation of clear icing is freezing rain below a frontal surface.Answer (A) is incorrect because although cumulus clouds with below-freezing temperatures and freezing drizzle are conducive to structural icing, they will not have as high an accumulation rate as freezing rain. Answer (B) is incorrect because although cumulus clouds with below-freezing temperatures and freezing drizzle are conducive to structural icing, they will not have as high an accumulation rate as freezing rain.

An individual microburst will seldom last longer than 15 minutes from the time it strikes the ground until dissipation. However, there may be multiple microbursts in the area.

A continuous line of thunderstorms, or squall line, may form along or ahead of the front. Squall lines present a serious hazard to pilots as squall type thunderstorms are intense and move quickly. Squalls can occur at any altitude - they are not unique to high- or low-altitude operations.

The propeller produces thrust in proportion to the mass of air being accelerated through the rotating blades. If the air is less dense, propeller efficiency is decreased.