Definition
A sealing compound that cures to a flexible, rubber-like state rather than a hard, rigid one. Resilient sealants are used in aircraft structures and systems where the sealed joint must accept movement, vibration, pressure changes, or thermal expansion without cracking or losing its seal.
Plain English
A sealant that stays soft and stretchy after it sets, so it can flex with the parts it is sealing instead of cracking when they move.
Context Anchor
Seen in aircraft maintenance when sealing fuel tank areas, window frames, access panels, seams, and places where air, fuel, oil, or water must be kept from leaking through.
Derivation
Resilient comes from the Latin resilire, meaning to spring back. A resilient sealant springs back to shape after being flexed or compressed, which is exactly what is needed where parts move slightly against each other.
Why Pilots Care
Ensures fuel systems and pressurized areas remain leak-free despite the constant flexing and stress of flight.
Intuition Check
Do not read resilient here as “strong” in a general sense. In this term, resilient means the sealant remains flexible and can keep sealing while the aircraft parts move slightly.
Example Sentence 1
The integral fuel tank seams were sealed with a resilient sealant so they could flex with the wing during flight without leaking.
Example Sentence 2
Resilient sealant is preferred over rigid types in areas subject to vibration because it maintains integrity over time.