Text in force at CS27-10: from CS27-0, effective 14 Nov 2003.
Each suction lift fuel system and other fuel systems with features conducive to vapour formation must be shown by test to operate satisfactorily (within certification limits) when using fuel at a temperature of 43°C (110°F) under critical operating conditions including, if applicable, the engine operating conditions defined by CS 27.927 (b)(1) and (b)(2).
ED Decision 2003/015/RM · Source