FAA Airline Transport Pilot (ATM)Aircraft Performance and Weight and BalanceHard
An aircraft has an empty weight of 92,000 lb at CG station 610.0. Fuel of 20,000 lb is loaded at station 650.0, and cargo of 8,000 lb is loaded at station 700.0. What is the resulting aircraft CG station?
- AStation 650.0
- BStation 610.0
- CStation 622.7
- DStation 635.4
Show answer & explanationAnswer & explanation
Correct answer: C. Station 622.7
Total moment = (92,000×610)+(20,000×650)+(8,000×700) = 56,120,000 + 13,000,000 + 5,600,000 = 74,720,000. Total weight = 92,000+20,000+8,000 = 120,000 lb. CG = 74,720,000/120,000 = 622.67, which rounds to station 622.7.
Why the other options are wrong
- A. This is simply the fuel station, not the weighted average CG.
- B. This ignores the moment contributions of fuel and cargo entirely.
- D. This value results from an arithmetic error in the moment summation.
Weight & Balance Moment Calculation
Aircraft CG is found by summing all component moments (weight × arm) and dividing by total weight.
- Moment = weight × arm (station)
- CG = total moment / total weight
- Must include all loaded items: empty weight, fuel, payload, cargo
Memory trick: 'Sum the moments, divide by the mass, find where the balance point lasts'