FAA Part 107 Drone Practice Test

Which weather condition can affect the performance of a UA regarding density altitude?

1. High humidity

2. Low altitude

3. High density altitude

4. Clear skies

The correct answer is: High density altitude

High density altitude significantly impacts the performance of unmanned aircraft (UA) by reducing the amount of lift generated by the wings and decreasing engine performance. Density altitude refers to the altitude at which the air density is equal to that of a standard atmosphere at sea level. When density altitude increases, typically due to higher temperatures or lower barometric pressure, the air becomes less dense. This reduced density means that the aircraft’s propellers cannot push as much air downward, leading to decreased lift. Additionally, the engines may not be able to produce the same power as they would at lower density altitudes due to the thinner air, which can also affect fuel efficiency and overall vehicle performance. This is particularly important when flying in mountainous areas or at high elevations where density altitude may be significantly affected by environmental conditions. In contrast, other weather conditions such as high humidity can complicate flights but do not directly influence density altitude in the same way. Low altitude does not affect performance negatively; in fact, lower density altitude typically yields better performance for aircraft. Clear skies typically signify good weather conditions but do not relate directly to density altitude issues.