Definition
Secured against loosening, backing off, or coming undone in service, typically by means of safety wire, cotter pins, lock washers, locking nuts, or other mechanical locking devices. A fastener or component is described as 'safetied' once this secondary retention has been correctly installed.
Plain English
Locked in place with an extra physical device — like a wire or pin — so vibration or movement can't shake it loose.
Context Anchor
You may see this word in preflight, maintenance, and aircraft handling instructions, especially when checking that doors, panels, pins, caps, or fasteners are secure.
Derivation
From the noun 'safety' used as a verb in mechanical and aviation trades, meaning 'to make safe against loosening.' The past-tense form 'safetied' simply means the safety device has been installed.
Why Pilots Care
Loose hardware can cause loss of control or engine failure; safetied fasteners are required on critical aircraft systems.
Intuition Check
Do not read safetied as simply meaning “made safe” in a general way. In aviation, it usually means physically secured so it cannot loosen, open, or move unintentionally.
Example Sentence 1
After torquing the oil filter, the mechanic safetied it with stainless safety wire to the engine case.
Example Sentence 2
During the preflight walk-around, the pilot confirmed the landing-gear bolts were safetied.