AMC E 60(d)  Provision for instruments

ED Decision 2007/015/R

(1)     For the purpose of complying with CS-E 60(d), the 30-Second OEI power level is considered to be used whenever one or more of the operating limitations applicable to the 2-Minute OEI power level are exceeded. The 2-minute OEI power level is considered to be used whenever one or more of the operating limitations applicable to the next lower OEI power rating or other Engine rating (if applicable) are exceeded.

(2)     The required means, provided by the applicant or by the rotorcraft manufacturer, are intended to automatically record the entry into, and the subsequent usage of, the defined power levels, and to enable the pilot to be automatically alerted of the entry into the power levels and the corresponding impending time expiration and the time expiration point. The automatic recording should be compatible with the maintenance instructions prescribed for these ratings. In particular, it should record the number of usages and time of each usage or accumulated time, including any exceedence of 30-Second OEI and/or 2-Minute OEI operating limitations or relevant time limitations. It should also provide a means to alert the maintenance personnel that usage and/or exceedence of 30-Second and/or 2-Minute OEI power have taken place. See also paragraph (5) of AMC E 40(b) regarding exceedence of the 2 minute time limitation at 2-Minute OEI power.

(3)     The objective is to ensure that the information needed for the mandatory maintenance actions is available after the use of 30-Second and/or 2-Minute OEI power, thus avoiding continued operation of the Engine in a potentially unsafe condition. The overall development assurance level of the recording and retrieval system should be consistent with this objective. The development assurance level(s) of the components of the systems used to record usage and to retrieve the record of the 2-Minute and 30-Second OEI powers should be based on the criticality of the function(s) performed within the recording and retrieval system as determined through the system safety analysis required under CS-E 50(d). The overall system assurance level can be achieved based on an appropriate combination of system architecture and component assurance levels.

If the recording and/or retrieval system is not part of the Engine, the aircraft should still comply with CS-27/29.1305 specifications. The applicant should specify in the instructions for installation that the objective of this recording/retrieval system is to ensure that the information needed for the mandatory maintenance actions is available after the use of 30-Second and/or 2-Minute OEI power, thus avoiding continued operation of the Engine in a potentially unsafe condition and that the overall development assurance level of the recording and retrieval system should be consistent with this objective.

(4)     The recording systems should only be able to be reset by the maintenance personnel and not by the flight crew in order to prevent further Engine operation without having taken the prescribed mandatory post-flight inspection and maintenance actions.

(5)     An Engine can be approved with 30-Second/2-Minute OEI Power Ratings and any combination of Maximum Engine Over-torque, Maximum Engine Over-speed and Maximum Exhaust Gas Over-Temperature in compliance with CS-E 820, 830, and 870. In such a case, Engine operation above the Take-off Rating limits but within the limits established under CS-E 820, 830, and 870 need not be considered as usage of 30-Second/2-Minute OEI Power Ratings if the event was a true over-torque, over-speed or over-temperature event and it can be demonstrated that the recording system is able to distinguish between;

(i)      an Engine over-speed, over-torque or over-temperature with all Engines operating, and

(ii)      use of the 30 Second/2 Minute OEI Power Ratings with one Engine inoperative.

[Amdt. No.: E/1]