Sec. 29.679 - Control system locks.
If there is a device to lock the control system with the rotorcraft on the ground or water, there must be means to --
(a) Automatically disengage the lock when the pilot operates the controls in a normal manner, or limit the operation of the rotorcraft so as to give unmistakable warning to the pilot before takeoff; and
(b) Prevent the lock from engaging in flight.