What is the maximum permissible fuel imbalance during all other phases of flight?

• A. 800 pounds
• B. 400 pounds
• C. 600 pounds
• D. 1000 pounds

Answer: (A)

Maintaining fuel balance between the left and right tanks keeps the airplane’s center of gravity and lateral stability within safe limits. When one wing holds more fuel, it creates a yawing moment that the rudder and stability effects must counteract. The aircraft is designed to tolerate up to 800 pounds of imbalance during all phases except the most sensitive ones, because with that difference the center of gravity remains within the approved envelope and there’s typically enough rudder authority to manage any resulting yaw.

There are tighter limits during critical phases like takeoff and landing, where the handling needs extra margin in case of an engine failure or unexpected gusts. The other choices would either impose unnecessary restrictions or exceed what the design allows for safe flight.