SBIR-STTR Award

A flexible hose and drogue system typically employed in military aircraft refueling operations has proven reliable except when excessive shear forces on the receiving aircrafts refueling probe are induced, which can induce a break-away design feature. New concepts are required to eliminate this break-away feature, reducing FOD and potential damage to the aircraft. This requires a new innovative probe design that can withstand high loads and will not break-away, resulting from utilization of a high strength and flexible attachment mechanism. Innovative concepts may include flexible linkages, active control devices or other attachment mechanisms that can absorb the loads on the probe relative to the drogue. Phase I will develop refueling simulation models of the flexible hose and drogue with the receiving aircrafts refueling probe to predict the induced loads relative to specified operational parameters. The simulation models will be based on existing cable-body dynamic analysis software and a 6 DoF aircraft model in an integrated simulation. Design concepts will then be developed and examined in a number of parametric studies for typical operational scenarios to demonstrate the design feasibility. One or two of the most promising concepts will be down-selected for consideration in Phase II prototype development and testing.

Benefit:
Several anticipated benefits will result from a new innovative probe design that does not contain a break-away feature. Reduced FOD, improved refueling capability, greater safety and reduced risk to the receiving aircraft, and reduced maintenance costs will be achieved. Enhanced reliability for military aerial refueling where failures can have a great cost in terms of mission success, battle effectiveness and military hardware will be gained. The technology developed will attract wide application in other military refueling operations, including the US Navy, US Air Force, NASA and others. The commercial tanking industry that uses contractor owned aircraft to refuel military and support contractor aircraft would also benefit.

Keywords:
Refueling modeling, Refueling modeling, Flight refueling probe, Flexible Refueling Probe, Probe loads, Probe design, Parametric Study, integrated simulation, aerial 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 aircrafts 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 0x9D type component, referred to as an Overload Mitigation Unit 0x9D (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.

Benefit:
Several anticipated benefits will result from a new innovative probe design that does not contain a break-away feature for the overload case. Reduced FOD, improved refueling capability, greater safety and reduced risk to the receiving aircraft, and greater hose and drogue operational capability will be gained. Enhanced reliability for military aerial refueling, where failures can have a great cost in terms of mission success, battle effectiveness and military hardware will be achieved. The technology developed will attract a wide audience with application to other military refueling operators including the US Navy, US Air Force, US Marine Corps, NASA and defense industry prime contractors. Other worldwide military programs that use probe and drogue refueling could also benefit. The commercial tanking industry that uses contractor owned aircraft to refuel military and support contractor aircraft could also use the new probe design. Applications into the UAV and UCAV markets present significant new opportunities for this advanced design concept.

Keywords:
flexible component, risk reduction, FOD, overload mitigation, dynamic analysis, aerial refueling, refueling probe, hose whip