FAA Aerodynamics of sUAS

Question 1

In straight-and-level, unaccelerated flight, which statement about the four aerodynamic forces is correct?

Accepted Answer

Lift equals weight and thrust equals drag

Answer

In unaccelerated level flight, opposing forces must be equal — lift balances weight and thrust balances drag.

Question 2

What effect does high density altitude have on sUAS rotor performance?

Accepted Answer

Rotor efficiency decreases because less dense air generates less lift per revolution

Answer

Thinner air at high density altitude means each rotor revolution moves less air mass, reducing lift and requiring higher RPMs to maintain hover.

Question 3

Which combination of environmental conditions results in the highest density altitude?

Accepted Answer

High elevation, hot temperature, high humidity

Answer

High elevation reduces pressure, hot temperatures reduce air density, and high humidity displaces denser oxygen molecules — all three factors combine to create maximum density altitude.

Question 4

What is 'ground effect' as it applies to multirotor sUAS operations?

Accepted Answer

Increased rotor efficiency caused by reduced induced drag when flying close to the ground

Answer

Ground effect occurs when rotor downwash is interrupted by the ground surface, reducing induced drag and increasing lift efficiency within approximately one rotor diameter of the surface.

Question 5

As an sUAS enters a steeper banked turn, what happens to the load factor and power requirement?

Accepted Answer

Load factor increases and power requirement increases

Answer

In a banked turn, the vertical component of lift must still support the aircraft's full weight, so total rotor thrust must increase — raising both load factor and power draw.

FAA - Part 107 Test Practice Test

FAA - Part 107 Test Practice Test

FAA Aerodynamics of sUAS