IRImplementing rule
I 25.6 Powerplant controls
(a)General
(1)In addition to the requirements of CS 25.1141, no single failure or malfunction, or probable combination thereof, of the ATTCS system, including associated systems, may cause the failure of any powerplant function necessary for safety.
(2)The ATTCS system must be designed to perform accurately its intended function without exceeding engine operating limits under all reasonably expected conditions.
(b)Thrust or Power Lever Control. The ATTCS system must be designed to permit manual decrease or increase in thrust or power up to the maximum thrust or power approved for use following engine failure during take-off through the use of the normal thrust or power controls, except that, for aeroplanes equipped with limiters that automatically prevent engine operating limits from being exceeded, other means may be used to increase thrust or power provided that the means is located in an accessible position on or close to the thrust or power levers, is easily identified, and operated under all operating conditions by a single action of either pilot with the hand that is normally used to actuate the thrust or power levers.
(c)System Control and Monitoring. The ATTCS system must be designed to provide –
(1)A means for checking prior to takeoff that the system is in an operable condition; and
(2)A means for the flight crew to deactivate the automatic function. This means must be designed to prevent inadvertent deactivation.
IR — CS-25 · ED Decision 2003/2/RM · CS-25 Easy Access Rules · EAR revision 26 Jan 2023