FAA Airline Transport Pilot (ATM)Aircraft Performance and Weight and BalanceMedium
A dispatcher is computing the maximum allowable landing weight for a twin-engine turbojet limited by the approach climb requirement at the destination. Per 14 CFR Part 25 certification standards, the approach climb gradient is demonstrated with one engine inoperative, in which configuration?
- ALanding flaps extended, landing gear down, with all engines operating
- BApproach flaps extended, landing gear retracted, at go-around thrust
- CFlaps and gear retracted (clean configuration), at maximum continuous thrust
- DLanding flaps extended, landing gear down, at approach climb thrust
Show answer & explanationAnswer & explanation
Correct answer: B. Approach flaps extended, landing gear retracted, at go-around thrust
The Part 25 approach climb requirement (25.121(d)) is demonstrated with the critical engine inoperative, the remaining engines at go-around (takeoff) thrust, gear retracted, and flaps in the approach (not landing) setting, simulating a go-around from an approach. This requirement often limits maximum landing weight at high, hot, or obstacle-limited airports.
Why the other options are wrong
- A. All-engine operation is used for the landing climb gradient, not the OEI approach climb requirement.
- C. Clean configuration with all engines does not represent either landing-phase climb requirement.
- D. This describes the landing climb requirement (all-engine, landing configuration), not approach climb.
Approach Climb Gradient
A Part 25 certification requirement demonstrating a minimum climb gradient with one engine inoperative, gear up, approach flaps, and go-around thrust, simulating a missed approach.
- One engine inoperative, gear retracted, approach flap setting
- Minimum gradient for two-engine airplanes is 2.1%
- Often the limiting factor for landing weight at high/hot/high-terrain airports
Memory trick: Approach climb = 'Almost landed, one Alive engine, gear still up.'