Definition
A registered trade name for a strong, thin, transparent polyester film used in aviation for items such as control-surface fabric coverings, balloon and airship envelopes, instrument diaphragms, and protective overlays on charts and placards.
Plain English
Mylar is a tough, lightweight plastic sheet. In aviation it shows up as a clear protective film, a covering material on some aircraft surfaces, and inside certain instruments.
Context Anchor
Seen in aircraft maintenance instructions, repair procedures, electrical work, and shop materials lists.
Derivation
Mylar is a brand name coined by the DuPont company in the 1950s for its biaxially-oriented polyethylene terephthalate (BoPET) film. Knowing it is a brand name (like Velcro or Kleenex) helps explain why the word is capitalized and why it refers to one specific manufactured product rather than a generic material.
Why Pilots Care
Provides a durable, lightweight covering option that resists tearing and environmental damage in homebuilt and ultralight aircraft.
Intuition Check
Mylar does not mean ordinary plastic wrap. In aircraft work, it means a specific tough polyester film used where its strength, thinness, or insulating qualities matter.
Example Sentence 1
The mechanic applied a Mylar covering to the wing during the recovering process.
Example Sentence 2
During the preflight, the pilot noticed a small tear in the Mylar covering near the wing root and scheduled a repair.