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CS 31HB.45 Fuel cells

ED Decision 2009/005/R

(a)     It must be demonstrated by test or analysis or both that fuel cell’s have sufficient strength margins to withstand all conditions of internal and external pressures, temperatures and loads likely to be encountered in operation, including during ground handling and ground transport. (See AMC 31HB.45(a))

(b)     The compatibility of the cells material with the fuel must be justified. Fatigue, ageing, fire resistance and corrosion capability of the cells must be assessed and any necessary limitation, protection or maintenance action must be determined.

(c)      Fuel cells, their attachments and related supporting structure must be shown by tests to be capable of withstanding, without detrimental distortion or failure, any inertia loads to which the installation may be subjected in operation. (See AMC 31HB.45(c))

(d)     A pressurised fuel cell must be equipped with:

(1)     A shut-off valve. This valve must be equipped with a self-sealing coupling, or other means to avoid the release of hazardous quantities of fuel should the control be inadvertently operated without a fuel line connected. (See AMC 31HB.45(d)(1))

(2)     A pressure relief valve, which must protect the fuel cell against over pressurisation.

(3)     A means to control the maximum filling.

(4)     A means to assess the fuel quantity. (See also CS 31HB.47(c)(2))

(5)     A data plate containing information necessary for safe operation. (See AMC 31HB.45(d)(5))

(e)     Guards must be fitted to all fuel cells to protect the valves and other fittings from fuel leakage in case of:

(1)     Inadvertent operation and

(2)     Damage, during normal operation, ground handling or transport.

(f)      Rigid extensions must not be fitted directly to fuel cell valves or fittings due to the likelihood of overload or fracture occurring in the case of a hard or fast landing. (See also CS 31HB.46)