Part 107 unit6

What is the standard air temperature and pressure at sea level?

• 25 degrees Celsius and 950 hPa
• 10 degrees Celsius and 1020 hPa
• 20 degrees Celsius and 1000 hPa
• 15 degrees Celsius and Hg 29.92

What effect does high density altitude have on the efficiency of a UA propeller?

• reduces efficiency
• improves efficiency
• has no effect on efficiency
• increases efficiency

What is true altitude?

• Distance of a point below the mean sea level
• Vertical distance of a point above the mean sea level
• Horizontal distance of a point above the mean sea level
• Distance of a point above the ground level

Which combination of atmospheric conditions will reduce aircraft

• Low temperature, low relative humidity, and low density altitude

• High temperature, low relative humidity, and low density altitude.  

• High temperature, high relative humidity, and high density altitude.

If the outside air temperature (OAT) at a given altitude is warmer than standard, the density altitude is

• lower
• higher
• unchanged

Density altitude is defined by

• pressure altitude and ambient temperature.

• The altitude at which the air density is lowest.
• The altitude at which the air density is highest.
• The altitude at which the air density is zero.

What effect, if any, does high humidity have on sUAS performance

• High humidity can decrease performance.

• High humidity has no effect on sUAS performance.
• High humidity can increase lift and flight time.

Which factor would likely increase density altitude?      

• Visibility, precipitation, or wind direction
• Wind speed, cloud cover, or barometric pressure
• An increase in ambient temperature

• Latitude, longitude, or time of day

When is pressure altitude equal to density altitude?

• When the atmospheric conditions are non-standard.
• When the altitude is below sea level.
• On a standard day (15º C and 29.92” Hg

• When the temperature is below freezing.

How would high density altitude affect the performance of a small unmanned aircraft?

• It increases engine power and lift,

• It reduces performance

• It has no effect on engine power and lift.
• It improves engine power and lift, resulting in faster takeoff and landing distances.