What is the secondary or backup refueling method called for the T-6A?

The secondary or backup refueling method for the T-6A is known as over the wing gravity refueling. This method involves transferring fuel into the aircraft's fuel tanks from above, allowing gravity to facilitate the flow of fuel. Over the wing refueling is particularly useful in situations where the primary refueling method—single point pressure refueling—may be unavailable or inoperative.

This method offers several operational advantages, including its simplicity and effectiveness in replenishing fuel without the need for specialized equipment. It is particularly advantageous in deployments or locations where quick refueling is required, and pressure refueling systems might not be readily available.

The other methods listed, while important for understanding refueling protocols, do not serve as the designated secondary method for the T-6A specifically. Single point pressure refueling is the standard method employed, and gravity feed refueling may refer to alternate processes but does not specify the over the wing approach characterized by the T-6A system. Direct feed refueling is not a recognized term associated with the T-6A's standard procedures.