AMC 25.1043 Cooling tests

• ED Decision 2014/026/R found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

AMC 25.1043 Cooling tests ED Decision 2014/026/R In accordance with [CS 25.1041](#_DxCrossRefBm1709821499), applicants must show that the cooling provisions can maintain the temperatures of powerplant components and engine fluids within the temperature limits for which they have been certified, under ground and flight operating conditions, and after normal engine shutdown. [CS 25.1043(b)](#_DxCrossRefBm1709821500) establishes 37.8° C (100°F) at sea level as the lowest maximum ambient temperature, except for winterisation installations. Applicants may establish a higher temperature limit if desired. The assumed temperature lapse rate is 6.6°C per thousand meter (3.6°F per thousand feet) of altitude above sea level until a temperature of -56.5°C (–69.7°F) is reached, above which altitude the temperature is considered at -56.5°C (–69.7°F). The compliance demonstration flight test should be conducted with an ambient temperature as close to the desired maximum ambient atmospheric temperature as practical; the maximum temperature deviation should not normally exceed 13.9°C (25°F). If testing is accomplished at lower ambient temperatures, then the test data must be corrected to that which would have resulted from testing on a day with the maximum ambient atmospheric temperature. The maximum ambient temperature selected and demonstrated satisfactorily, taking account of correction factors, shall not be less than the minimum hot day conditions prescribed by CS 25.1043(b) and shall be an aeroplane operating limitation per the requirements of [CS 25.1521(d)](#_DxCrossRefBm1709820849). The applicant should correct the engine temperatures to as high a value as possible in order to minimise the impact of this limitation. [Amdt 25/15]