Crashworthy Ballistic Tolerant Fuel Tank Weight Reduction

The pressure to reduce weight and maintain performance and safety is a significant driver in aviation technology development programs. Fuel and fuel systems are major contributors to weight on aircraft, including fuel cells, fittings, access panels and support structures. The design of the fuel cell is dictated by requirements to integrate the fuel cell into the aircraft structure, facilitate access and maintenance, and most importantly to protect the warfighter in the event of a crash or assault. The objective of the current program is to reduce the parasitic weight of MIL-DTL-27422 Type I, Class A fuel tanks by 50% below the lightest weight system construction currently qualified, which has a construction weight of approximately 0.9 lb/ft2 of surface area. The lightweight bladder construction should continue to meet all of the performance requirements of MIL-DTL-27422, allow easy removal and replacement at the unit maintenance level, and be scaleable and affordable. METSS proposes to address the program objectives through a combination of materials design changes including (1) a reduction in the number of laminate plies used in the existing MIL-DTL-27422 panel construction through the use of stronger, tougher, more damage and impact tolerant fabrics, (2) the use of lighter weight fabrics, and (3) by replacing the self-sealing layer with more effective sealing materials. Based on the Phase I program results, METSS is targeting a total panel areal density of 0.30 lb/ft2 under the Phase II program. Importantly, the Phase II program plan includes full MIL-DTL-27422 Phase I test qualification and Phase II product qualification for an existing helicopter fuel cell design.