An Innovative In-Flight Refueling Probe Component that Eliminates Accidental Overload of the Mast Assembly During Air Refueling

A flexible hose and drogue system typically employed in aircraft refueling operations has proved reliable except when excessive forces are induced on the receiving aircraft’s refueling probe, invoking a break-away design feature and potentially creating FOD. A new approach is required to eliminate this break-away design feature, thus avoiding FOD and potential significant damage to the aircraft. This requires development of an innovative probe design that can withstand the high loads caused from a hose whip condition and will not break-away, due to the introduction of a high strength and flexible component into the probe mast. Design concepts have been developed and examined through a number of dynamic performance analyses for typical operational scenarios to demonstrate feasibility. The most promising concept is a flexible “torque wrench” type component, referred to as an “Overload Mitigation Unit” (OMU), which was down-selected for prototype development and testing in Phase II. Other concepts were also considered that include a composite refueling probe mast assembly to replace the current aluminum design, adding greater flexibility to the assembly. The combination of a composite probe mast with an OMU showed positive results and will also be considered in a more detailed analysis in the Phase II program.