AMC1 27.1045 Cooling test procedures

• ED Decision 2023/001/R found in: CS-27 Amdt 10 - Small Rotorcraft (Feb 2023)

AMC1 27.1045 Cooling test procedures ED Decision 2023/001/R (a) Introduction This AMC supplements FAA AC 27-1B, § AC 27.1045A and should be used in conjunction with that AC when demonstrating compliance with [CS 27.1045](#_DxCrossRefBm8894050). (b) 30-minute power rating (1) Explanation The 30-minute power rating may be set at any level between the maximum continuous up to and including the take-off rating, and may be used for multiple periods of up to 30 minutes each, at any time between the take-off and landing phases in any flight. This use of this rating may affect the cooling capabilities of the rotorcraft. This potential impact should be evaluated during the certification. (2) Procedure In the case of usage of a 30-minute power rating, AC 27.1045A b) should be completed as such: Procedures. All of the policy material pertaining to this section remains in effect except that the engine fluid temperatures do not have to be stabilised. Paragraph AC 27.1045 currently lists three criteria for test completion: temperature stabilisation, flight test segment completion, or an operation limitation. With Amendment 27-23, a fourth criterion for test completion is: — 5 minutes after the peak temperature is reached, the test can be considered to be complete, or — the continuous time limit of the 30-minute power rating if the highest temperature recorded is not stabilised before. [Amdt 27/10]