Definition
A highly flammable plastic-like material made by treating cellulose (plant fiber) with nitric acid, historically used as a clear coating (dope) on fabric-covered aircraft to tighten and protect the fabric, and as a base for early aircraft finishes.
Plain English
A treated plant-fiber material, often used as a clear liquid coating that dries into a tough film. It was painted onto fabric aircraft skins to make them tight and weatherproof. It catches fire very easily.
Context Anchor
Seen in aircraft fabric-covering, restoration, and maintenance discussions, especially on older or fabric-covered airplanes.
Derivation
Cellulose is the fibrous material that makes up plant cell walls. Nitrate refers to the chemical group added when cellulose is treated with nitric acid. Combining the two changes plain plant fiber into a tough, film-forming material that also happens to be very flammable.
Why Pilots Care
It allowed early airplanes to have strong, lightweight fabric skins, yet its high flammability caused many fires and led to safer modern dopes such as cellulose acetate butyrate.
Intuition Check
Do not think of cellulose nitrate as just ordinary paint. In aircraft use, it is a flammable fabric-coating material with specific handling and repair concerns.
Example Sentence 1
The fabric on the older trainer was finished with cellulose nitrate dope, so the mechanic kept all open flames well away from the hangar during recovering work.
Example Sentence 2
Because cellulose nitrate burns so readily, most current fabric-covered airplanes use a safer butyrate-based dope instead.