FAA Aerodynamics of sUAS 3

Question 1

How does wind shear affect sUAS flight operations?

Accepted Answer

A sudden change in wind speed or direction can cause rapid attitude changes and potential loss of control

Answer

Wind shear only affects fixed-wing aircraft above 1,000 feet AGL

Answer

Wind shear improves sUAS stability by providing consistent airflow to the rotors

Answer

Small UAS are too light to be significantly affected by wind shear

Question 2

How does operating in hot, humid summer conditions affect sUAS endurance compared to cool, dry conditions?

Accepted Answer

Hot, humid conditions reduce endurance because lower air density requires higher RPMs for the same lift

Answer

Hot, humid conditions improve endurance because warm air provides more lift

Answer

Temperature and humidity only affect fixed-wing aircraft endurance, not multirotors

Answer

Endurance improves in hot conditions because lithium batteries perform better at higher temperatures

Question 3

What is the primary aerodynamic concern when operating an sUAS near large buildings or other tall structures?

Accepted Answer

Mechanical turbulence and unpredictable wind gusts caused by airflow disruption around the structures

Answer

Magnetic interference that disrupts compass sensors

Answer

Increased air density near structures that reduces rotor efficiency

Answer

Reflections from building surfaces that interfere with optical flow sensors

Question 4

How can a strong tailwind affect an sUAS during high-speed forward flight?

Accepted Answer

A strong tailwind reduces relative airspeed over the rotors, decreasing control effectiveness and lift efficiency

Answer

A tailwind always improves performance by adding to ground speed

Answer

Tailwinds have no aerodynamic effect on multirotor sUAS

Answer

Tailwinds cool the motors by increasing airflow, improving overall efficiency

Question 5

What phenomenon commonly occurs when an sUAS performs a rapid deceleration (quick stop) from high-speed forward flight?

Accepted Answer

The aircraft pitches nose-high and may experience a momentary altitude loss before stabilizing

Answer

The aircraft experiences increased lift from the sudden airflow change over the rotors

Answer

The motors automatically reduce power to avoid rotor over-speed

Answer

The landing gear deploys automatically to prevent a hard landing

Question 6

How do thermal updrafts and convective activity during midday hours affect sUAS flight stability?

Accepted Answer

Thermal updrafts create localized vertical air movement and turbulence that can cause unpredictable attitude changes

Answer

Thermals improve sUAS stability by providing consistent upward lift

Answer

Convective activity only affects operations above 1,000 feet AGL

Answer

Thermal activity has no measurable effect on sUAS below 55 lbs

Question 7

How does operating at high altitude affect both battery performance and the power required to maintain hover?

Accepted Answer

Cold temperatures at altitude reduce battery capacity while reduced air density simultaneously requires more power, compounding endurance loss

Answer

Battery performance improves at high altitude due to cooler temperatures increasing cell voltage

Answer

Battery performance is unaffected by altitude since it is an electrical rather than aerodynamic system

Answer

High altitude operation requires less power because the aircraft weighs less in thinner air