Text in force at CS29-12: from CS29-0, effective 14 Nov 2003.
(a) Each fuel system must be constructed and arranged to ensure a flow of fuel at a rate and pressure established for proper engi ne and auxiliary power unit functioning under any likely operating condi tions, i ncluding t he m anoeuvres for whi ch cert ification i s request ed and duri ng which the engine o r au xiliary p ower u nit is permitted to be in operation.
(b) Each fuel system must be arranged so that:
(1) No engine or fuel pum p can draw fuel from more than one tank at a time; or
(2) There are m eans to prevent introducing air into the system.
(c) Each fuel sy stem for a turbine engine must be capable of sustained operation throughout its flow and p ressure ran ge with fu el in itially saturated with wat er at 27°C (80°F) and havi ng 0.20 cm 3 o f free water p er litre (0 .75 cc p er US-gallon) added and cool ed t o t he m ost cri tical condition for i cing l ikely t o be encountered in operation.
ED Decision 2003/016/RM · Source