FAA Private Pilot Helicopter (PRH)WeatherHard
A helicopter pilot is landing on a dry, unimproved dirt surface in calm wind conditions. As the helicopter descends through ground effect, rotor downwash begins kicking up loose surface material, rapidly reducing the pilot's outside visual references just before touchdown. This hazardous condition is best described as
- AVortex ring state
- BSettling with power
- CBrownout
- DWhiteout
Show answer & explanationAnswer & explanation
Correct answer: C. Brownout
Brownout occurs when rotor downwash lifts loose dust, sand, or dirt from a dry unimproved surface during approach or landing, obscuring the pilot's outside visual references. Whiteout is the analogous condition caused by blowing snow, while vortex ring state and settling with power are aerodynamic hazards unrelated to obscured visibility from surface debris.
Why the other options are wrong
- A. Vortex ring state is an aerodynamic condition from descending into your own rotor downwash, not a visibility hazard.
- B. Settling with power describes high sink rate with insufficient power to arrest it, unrelated to obscured vision from dust.
- D. Whiteout results from blowing snow, not dust from a dirt surface.
Brownout
A hazardous condition where rotor downwash lifts dust or sand from a dry, unimproved surface, severely reducing or eliminating the pilot's outside visual references during approach or landing.
- Occurs mainly over dry, loose soil, sand, or dust
- Most severe near the ground where downwash concentrates
- Can lead to spatial disorientation and hard/dynamic rollover landings
- Whiteout is the analogous hazard caused by blowing snow
Memory trick: 'Brown dirt, Brownout; White snow, Whiteout'