FAA Private Pilot Helicopter (PRH)WeatherMedium
A helicopter pilot departing from an airport in the Western United States is briefed on a forecast for 'low-level wind shear'. What is the primary hazard associated with low-level wind shear for helicopters?
- AReduced effectiveness of anti-ice/de-ice systems.
- BRapid changes in altimeter settings.
- CSudden, uncommanded changes in airspeed and altitude.
- DIncreased static electricity buildup on the airframe.
Show answer & explanationAnswer & explanation
Correct answer: C. Sudden, uncommanded changes in airspeed and altitude.
Low-level wind shear, especially microbursts or frontal wind shear, involves sudden and significant changes in wind direction and/or speed over short distances. For helicopters, this can lead to abrupt and uncommanded changes in airspeed, altitude, and rotor RPM, potentially causing loss of control, especially during takeoff and landing.
Why the other options are wrong
- A. Anti-ice/de-ice systems are for icing conditions, which are separate from wind shear, although both can occur simultaneously.
- B. Wind shear primarily affects aircraft performance, not altimeter settings, which are based on atmospheric pressure.
- D. Static electricity is generally associated with precipitation or dust, not directly with wind shear.
Low-Level Wind Shear
Low-level wind shear is a sudden, drastic change in wind speed and/or direction over a very short distance, typically within 2,000 feet AGL. It can occur horizontally, vertically, or both, and is particularly hazardous during takeoff and landing.
- Can be caused by fronts, thunderstorms, terrain, or temperature inversions.
- Causes uncommanded changes in airspeed, altitude, and rotor RPM.
- Extremely dangerous for all aircraft, especially helicopters, during critical phases of flight.
Memory trick: Wind Shear: Wicked Sudden Changes Hurt Airplanes.