What is the secondary method of refueling the T-6 aircraft?

The secondary method of refueling the T-6 aircraft is over the wing gravity refueling. This method is often utilized due to its simplicity and effectiveness, especially in scenarios where quick refueling is necessary without specialized equipment. Gravity refueling allows for the fuel to flow from the fuel tank or container into the aircraft's fuel system under the influence of gravity, making it a straightforward process that can be performed with minimal personnel or equipment.

Over the wing gravity refueling is beneficial in training environments and operational military contexts, ensuring that aircraft can be efficiently refueled when other methods are unavailable or impractical. This procedural choice reflects a balanced approach to maintaining aircraft readiness while ensuring that pilots and ground crews are proficient in multiple refueling techniques.