Sec. 25.1155 - Reverse thrust and propeller pitch settings
below the flight regime.
Each control for reverse thrust and for propeller pitch settings below the flight regime must have means to prevent its inadvertent operation. The means must have a positive lock or stop at the flight idle position and must require a separate and distinct operation by the crew to displace the control from the flight regime (forward thrust regime for turbojet powered airplanes).
[Amdt. 25-11, 32 FR 6913, May 5, 1967]