14 CFR §25.607
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
- (a)Each removable bolt, screw, nut, pin, or other removable fastener must incorporate two separate locking devices if—
- (b)The fasteners specified in paragraph (a) of this section and their locking devices may not be adversely affected by the environmental conditions associated with the particular installation.
- (c)No self-locking nut may be used on any bolt subject to rotation in operation unless a nonfriction locking device is used in addition to the self-locking device.