Text in force at CS29-12: from CS29-0, effective 14 Nov 2003.
(a) Each removable bolt, screw, nut, pin or other fastener whose loss could j eopardise the safe operation of the rotorcraft m ust incorporate two separate locking devices. The fastener and its locking devices may not be adversely affected by the environmental conditions associated with the particular installation.
(b) No self-locking nut may be used on any bolt subject to rotation in operation unles s a non-friction locking device is used in addition to the self-locking device.
ED Decision 2003/016/RM · Source