7.6 Operating in Extreme Weather - Quiz Questions

SIGMETs are issued as a warning of weather conditions hazardous to which aircraft?

• Small aircraft only

• Large aircraft only

• All aircraft

Answer explanation

SIGMETs and AIRMETs are reports designed for manned aircraft traffic but applicable to all pilots operating their aircraft in the skies, regardless of size, whether butt-in-seat or remotely from the ground.

AIRMETs are advisories of significant weather phenomena (but of lower intensities than SIGMETs) and are intended for dissemination to

• only sUAS pilots.

• all pilots.

• only manned aircraft pilots.

Answer explanation

SIGMETs and AIRMETs are reports designed for manned aircraft traffic but applicable to all pilots operating their aircraft in the skies, whether butt-in-seat or remotely from the ground.

SELECT ALL THAT APPLY:

Some of the challenges of flying in freezing temperatures can be:

• Lower battery capacity on transmitter, monitor, aircraft power, etc.

• Poor sensitivity on the control sticks

• Greater battery capacity on transmitter, monitor, aircraft power, etc.

Answer explanation

A Remote PIC can be greatly affected by the cold. Numb fingers can be a very bad thing when the feel of the controls on the remote is so important. With a numb thumb one could easily bump the throttle down and not feel it. A bad bump could mean reducing thrust enough that your beautiful bird falls from the sky.

Batteries can also be greatly affected by the cold. Reduced performance is expected. This is very important to keep in mind for those who time their flights rather than keeping an eye on battery voltage.

The thunderstorms that are generally the most hazardous to aircraft are

• warm front thunderstorms.

• steady-state thunderstorms.

• squall line thunderstorms.

Answer explanation

Generally, the most severe thunderstorm conditions (like destructive winds, tornadoes, heavy hail, etc.) are associated with squall line thunderstorms. A squall line is a nonfrontal, narrow band of thunderstorms usually ahead of a cold front.

There's thunderstorm activity in the vicinity of your flight area. Which hazardous atmospheric phenomenon should you watch out for?

• Steady rain

• Precipitation static

• Wind-shear turbulence

Answer explanation

Thunderstorms begin with the cumulus stage, in which lifting action of the air begins. If sufficient moisture and instability are present, the clouds continue to increase in vertical height. Vertical development always means wind shear and turbulence, which is almost always more than an sUAS can handle.

A nonfrontal, narrow band of active thunderstorms that often develop ahead of a cold front is known as a

• prefrontal system.

• squall line.

• dry line.

Answer explanation

Generally, the most severe thunderstorm conditions (like destructive winds, tornadoes, heavy hail, etc.) are associated with squall line thunderstorms. A squall line is a nonfrontal, narrow band of thunderstorms usually ahead of a cold front.

What conditions are necessary for a thunderstorm to form?

• Lifting force, moist air, and extensive cloud cover

• High humidity, lifting force, and unstable conditions

• High humidity, high temperature, and cumulus clouds

Answer explanation

Thunderstorms are produced by cumulonimbus clouds.

They form when there is:

High Humidity - sufficient water vapor or moisture (Did you know that “nimbus” means rain?)

Unstable Conditions - An unstable lapse rate (the lapse rate describes the rate of change of the temperature as the air increases in altitude)

Lifting Force - An initial upward boost to start the process (heat)

Which thunderstorm life cycle stage is mostly characterized by downdrafts?

• Cumulus

• Dissipating

• Mature

Answer explanation

In the third and final stage of a thunderstorm, once the vertical motion near the top of the cloud slows down, the top of the cloud spreads out and takes on an anvil-like shape. At this point, the storm enters the dissipating stage. This is when the downdrafts spread out and replace the updrafts needed to sustain the storm.

A thunderstorm will reach its greatest intensity during the

• cumulus stage.

• downdraft stage.

• mature stage.

Answer explanation

Within approximately 15 minutes of a thunderstorm starting, it enters the second or "mature" stage, which is the most violent time period of the thunderstorm’s life cycle. At this point, drops of moisture, whether rain or ice, are too heavy for the cloud to support and begin falling in the form of rain or hail. This creates a downward motion of the air. Warm, rising air; cool, precipitation-induced descending air; and violent turbulence all exist within and near the cloud. Below the cloud, the down-rushing air increases surface winds and decreases the temperature.

What feature is typically associated with the cumulus stage of a thunderstorm?

• Continuous updraft

• Frequent lightning

• Roll cloud

Answer explanation

Thunderstorms begin with the cumulus stage, in which lifting action of the air begins. If sufficient moisture and instability are present, the clouds continue to increase in vertical height. Vertical development always means wind shear and turbulence, which is almost always more than an sUAS can handle.

Continuous, strong updrafts prohibit moisture from falling. The updraft region grows larger than the individual thermals feeding the storm.