FAA Airline Transport Pilot (ATM)Aircraft Performance and Weight and BalanceHard
Performance charts for a planned departure show the following maximum allowable takeoff weights: field length limit 165,000 lb; climb limit 158,000 lb; obstacle clearance limit 162,000 lb; structural maximum takeoff weight 170,000 lb. What is the maximum allowable takeoff weight for this departure?
- A170,000 lb
- B158,000 lb
- C162,000 lb
- D165,000 lb
Show answer & explanationAnswer & explanation
Correct answer: B. 158,000 lb
The maximum allowable takeoff weight is always the LOWEST of all applicable weight limits (structural, field length, climb, and obstacle clearance). Here the climb limit of 158,000 lb is the most restrictive, so it governs.
Why the other options are wrong
- A. This is the structural limit, which is not the most restrictive value here.
- C. This is the obstacle limit but is not the lowest applicable value.
- D. This is the field-length limit but is not the lowest applicable value.
Weight-Limited Takeoff Weight
Actual maximum allowable takeoff weight equals the lowest of the structural, field-length, climb, and obstacle-limited weights.
- Always take the minimum of all limits
- Structural MTOW is a ceiling, not the automatic answer
- Climb and obstacle limits often govern at high density altitude
Memory trick: When in doubt, take the LOWEST number — the weakest link sets the limit.