Definition
A reinforced eyelet installed in the edge of a fabric-covered aircraft surface that allows trapped moisture to drain and the interior structure to ventilate. Marine grommets are designed for use on aircraft operated in or near salt water, and are larger and positioned differently than standard drain grommets to handle the higher moisture and corrosion exposure of the marine environment.
Plain English
A small reinforced hole in the fabric covering of an aircraft that lets water drain out and air flow through. The marine version is bigger and placed to suit aircraft used around salt water.
Context Anchor
Seen during fabric-covering work, inspection, or repair on fabric-covered aircraft, especially aircraft that may be exposed to rain, spray, or standing water.
Derivation
Grommet' comes from an old French word for a small ring or loop. 'Marine' simply means relating to the sea. Together it signals a drainage eyelet built for saltwater operations.
Why Pilots Care
Prevents wire damage and electrical faults that could lead to system failures or fires, particularly important in seaplanes and aircraft flown near water.
Intuition Check
Marine does not mean this part belongs only on a boat. In this aviation use, it means a water-protective drain grommet used where moisture or spray is a concern.
Example Sentence 1
The mechanic checked each marine grommet on the floatplane's wings to make sure water from the last flight had drained out.
Example Sentence 2
During the preflight, the pilot noticed a cracked marine grommet around the wing root wiring and noted it for maintenance.