CS 22.965 Fuel tank tests
CAA ORS9 Decision No. 1
(a) Each fuel tank must be able to withstand the following pressures without failure or leakage:
(1) for each conventional metal tank and non-metallic tank with walls not supported by the sailplane structure, a pressure of 0.25 bar;
(2) for each non-metallic tank with walls supported by the sailplane structure and constructed in an acceptable manner using acceptable basic tank material, and with actual or simulated support conditions, a pressure of 0.14 bar for the first tank of a specific design.