AMC1 27.1521 Powerplant limitations

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

AMC1 27.1521 Powerplant limitations ED Decision 2023/001/R (a) Introduction This AMC supplements FAA AC 27-1B, § AC 27.1521 and should be used in conjunction with that AC when demonstrating compliance with [CS 27.1521](#_DxCrossRefBm8894092). (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 rating is associated with some limitations which should be adequately established and declared. (2) Procedure [CS 27.1521(a)](#_DxCrossRefBm8894092) refers to the limits for which the engines are type certificated. This should include the 30-minute power rating usage and: — the associated usage limit: — maximum duration in one single shot up to 30 minutes; — cumulative limit, if any, in one flight; and — any other limits associated with the usage of the 30-minute power rating declared in the installation and/or operating manual of the engine. [Amdt 27/10]