FAA Private Pilot Helicopter (PRH)Performance and LimitationsMedium
A helicopter departs at maximum gross weight with fuel burn of 30 pounds per hour. After 1.5 hours of flight, how has the gross weight change affected the helicopter's out-of-ground-effect (OGE) hover performance capability?
- AWeight remained unchanged since fuel burn does not affect gross weight
- BWeight increased by 45 lb, degrading OGE hover performance
- CWeight decreased by 20 lb, degrading OGE hover performance
- DWeight decreased by 45 lb, improving OGE hover performance
Show answer & explanationAnswer & explanation
Correct answer: D. Weight decreased by 45 lb, improving OGE hover performance
Fuel burn of 30 lb/hr over 1.5 hours equals 45 lb (30 × 1.5 = 45). As gross weight decreases during flight, less power is required to hover, so OGE hover performance and hover ceiling improve.
Why the other options are wrong
- A. Fuel is consumed as weight and does affect gross weight throughout flight.
- B. Weight decreases (fuel is consumed), it does not increase.
- C. Incorrect fuel burn calculation; 30×1.5 equals 45, not 20.
Fuel Burn Effect on Gross Weight
As fuel is consumed during flight, gross weight decreases, which improves hover, climb, and overall performance capability.
- Fuel burned (lb) = fuel flow rate × time
- Lower gross weight improves hover ceiling and climb rate
- Performance planning should account for weight changes over a long flight
Memory trick: Burn fuel, lose weight, gain performance.