Design Parameters: Loads on external aircraft tanks arise from three main sources: Pressurization, Aerodynamic Loads, Inertial Loads. Specially developed computer modelling tools were developed to determine these loads for any pylon mounted strore, underwing or centerline and for a variety of aircraft (F-16, Mirage, F-4) according to MIL-A-8591G. Operating Environment Maximum Altitude 30000 ft Maximum Velocity 630 KTAS (M 0.95) Load Factor + 6.5 g to -2.5 g Test Pressure leakage 2 bar Test Pressure no failure 3.5 bar Fuel Transfer Pressure 0.8 bar Composite Fuel Tanks Material: Conventional tanks are manufactured from aluminium alloy which presents certain disadvantages: high cost, corrosion, catastrophic failure upon impact, fatigue low resistance. To overcome these disadvantages another materiel was selected and successfully used: Pre-pregnated epoxy reinforced with carbon fibre enables lower tooling costs, complex shapes and rapid repair in case of damage. Mechanical properties include high specific stiffness and strength and high resistance to fatigue. Lightning protection: The effects of lightning strike are reduced by incorporating a layer of aluminium mesh / glass fibre. This also provides electromagnetic shielding.