FAA Private Pilot Helicopter (PRH)Helicopter Aerodynamics and SystemsMedium
A helicopter is loaded to maximum gross weight for a hover-out-of-ground-effect departure on a hot day at a high-elevation airport. Compared to the same helicopter loaded at a lighter weight under the same conditions, what effect does the increased gross weight have on hover performance?
- AIt has no effect on power required but decreases hover ceiling
- BIt increases the power required to hover and decreases hover ceiling
- CIt decreases the power required to hover and increases hover ceiling
- DIt increases the power required but increases hover ceiling
Show answer & explanationAnswer & explanation
Correct answer: B. It increases the power required to hover and decreases hover ceiling
A higher gross weight requires the rotor system to produce more lift, which requires greater blade pitch and induced drag, thus increasing power required to hover; this reduces the maximum altitude at which the helicopter can hover (hover ceiling) for given conditions.
Why the other options are wrong
- A. Power required does increase with weight, it does not stay constant.
- C. Increased weight requires more, not less, power to hover.
- D. Increased weight decreases, not increases, hover ceiling.
Weight Effect on Hover Performance
Increased gross weight requires greater rotor thrust, increasing power required to hover and lowering the hover ceiling.
- More weight requires more lift, more induced drag, more power
- Hover ceiling decreases as gross weight increases
- High density altitude compounds the power penalty of heavy loading
Memory trick: Heavier helicopter, higher power hunger, lower hover height