Definition
A screw designed to remain attached to the part it fastens, even when fully unscrewed. The threads disengage from the receiving part, but a retaining feature prevents the screw from falling out of its mounting hole.
Plain English
A screw that stays put in its panel or cover when you unscrew it, so it can't drop loose, get lost, or fall into the aircraft.
Context Anchor
Seen during aircraft inspection or maintenance, especially on access panels, covers, and equipment that must be opened and closed repeatedly.
Derivation
From the Latin captivus, meaning 'held' or 'taken prisoner.' The screw is 'held captive' by its mounting -- it can be loosened but cannot escape.
Why Pilots Care
Using captive screws on access panels reduces the risk of loose hardware entering critical aircraft systems and causing foreign object damage.
Intuition Check
A captive screw is not a screw that is jammed or impossible to remove. It is a screw that can be loosened, but is designed to stay attached to the panel or part.
Example Sentence 1
The avionics access panel is held on by four captive screws, so the technician doesn't have to worry about losing them during inspection.
Example Sentence 2
Four captive screws secured the battery compartment cover so none could be lost inside the engine area.