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Appendix L

Large Aeroplanes (CS-25) · CS-25 · EAR revision 26 Jan 2023

AppendixAppendix

Appendix L

Element of SystemStrength ValueRemarks
ProofUltimate
Rigid pipes and ducts Couplings Flexible hoses Return line elements1·5 PW 1·5 PW 2·0 PW –3·0 PW 3·0 PW 4·0 PW 1·5 PfPf The maximum pressure applied during failure conditions.
Components other than pipes, couplings, ducts or pressure vessels1·5 PW2·0 PW
Pressure vessels fabricated from metallic materials. (For non-metallic materials see CS 25.1436(b)(7)) Pressure vessels connected to a line source of pressure Pressure vessels not connected to a line source of pressure, e.g. emergency vessels inflated from a ground source3·0 PL or 1·5 PL4·0 PL or 2·0 PLThe lower values are conditional upon justification by a fatigue endurance test from which a permissible fatigue life is declared, and upon the ultimate load test being made on the test specimen used for the fatigue life test. The lower values are conditional upon justification by a life endurance test of a suitably factored permissible number of inflation/deflation cycles, including temperature fluctuation results in a significant pressure variation, and upon the ultimate load test being made on the test specimen used for the life endurance test. For all pressure vessels: (1) The minimum acceptable conditions for storage, handling and inspection are to be defined in the appropriate manual. See CS 25.1529. (2) The proof factor is to be sustained for at least three minutes. (3) The ultimate factor is to be sustained for at least one minute. The factor having been achieved, the pressure vessel may be isolated from the pressure source for the remaining portion of the test period.
2·5 PL or 1·5 PL3·0 PL or 2·0 PL

[Amdt 25/1]

APPENDIX · Appendix L — CS-25 · ED Decision 2005/006/R · CS-25 Easy Access Rules · EAR revision 26 Jan 2023

All rules in APPENDICES TO CS-25

Consolidated from the EASA Easy Access Rules (revision 26 Jan 2023, extracted 17 Aug 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.

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