Definition
A wearable flotation device designed to keep a person afloat with their face above water in the event of a forced landing or ditching over water. In aviation use, life preservers are typically inflatable vests stowed under or near each seat and are required equipment on aircraft operating beyond gliding distance from shore.
Plain English
A vest that keeps you floating in water if the aircraft has to ditch. It's stored on board and put on when needed.
Context Anchor
Seen in overwater flight planning, passenger briefings, and aircraft emergency equipment checks.
Derivation
From 'life' plus 'preserver' (one who preserves or keeps something safe). Literally, a device that preserves life — a plain-English name that describes exactly what it does.
Why Pilots Care
Required equipment for certain over-water operations; directly affects survival chances after a ditching.
Intuition Check
A life preserver does not mean any object that happens to float. In aviation, it means emergency flotation equipment intended for a person to use in water.
Example Sentence 1
Before the overwater flight, the pilot showed each passenger how to put on and inflate the life preserver stowed beneath their seat.
Example Sentence 2
After exiting the aircraft following the ditching, the passengers inflated their life preservers.