How many minutes prior to refueling completion must the tanker commander request further clearance from ATC?

The tanker commander must request further clearance from Air Traffic Control (ATC) at least five minutes prior to the completion of refueling. This timing is crucial for several operational reasons. First, it allows adequate time for ATC to process the request, which may involve updating flight plans and coordinating with other aircraft in the area. Additionally, aviation safety regulations require timely communication to ensure that all parties are aware of any changes in flight operations, especially when multiple aircraft are involved in refueling and transit operations. The five-minute window ensures that there is enough time to address any potential conflicts or necessary adjustments to air traffic in a busy airspace, thus enhancing safety and efficiency.