AMC E 740(c)(2)(i) Endurance Tests – 30-Minute Power Rating

For Rotorcraft turbine Engines to be approved with a 30-Minute Power rating:

(a)An applicant may propose either to include the required additional 25 hours within the overall test normally required by CS-E 740, or to perform a complementary test on the same test article used for the test required by CS-E 740, or a combination of these methods. If the additional 25 hours are included within the overall test normally required by CS-E 740, the modified test periods should be uniformly distributed throughout the endurance testing.

(b)Credit may be sought for time accrued during testing at the 30-Minute OEI rating required by CS-E 740. This allowance excludes the time spent at ‘standard’ Take-off Power. It should then be shown that these sequences were run with operating limitations that are equal to or more stringent than the 30-Minute Power rating operating limitations.

(c)It is possible that the intended usage and performance characteristics of the Engine may be such that its power will be subject to mechanical limitations for a certain portion of its missions. In that case, it may be acceptable to run the Engine for a representative percentage of the time that is required at the 30-Minute Power rating at these mechanical limitations, but not to exceed 50 % of the required additional 25 hours (i.e. 12.5 hours). For the remaining percentage of the time, the Engine should be run at the higher thermal limits. The proposal must be substantiated and proposed to the Agency for acceptance. These assumptions will be recorded in the instructions for installing and operating the Engine, in accordance with CS-E 30(a).

(d)No specific maintenance action is normally expected following the use of the 30-minute Power rating. This will be justified by compliance with CS-E 740(h)(1).

[Amdt No: E/5]