Definition
A solution of nitrocellulose dissolved in amyl acetate, used in aircraft fabric covering work as a thinner and adhesive carrier. It has a sweet, fruit-like odor resembling bananas, which is the source of its common name.
Plain English
A clear, sweet-smelling liquid used when working with fabric-covered aircraft surfaces. It thins out dope (the coating applied to fabric) and helps it spread or stick properly.
Context Anchor
Seen in aircraft fabric-covering, finishing, and coating discussions in airframe maintenance.
Derivation
Named for its smell, not its contents. The amyl acetate in the mixture has a strong banana-like odor, so shop workers nicknamed it 'banana oil.' It contains no actual banana and is not technically an oil in the lubricant sense.
Why Pilots Care
Mechanics and owners working on fabric-covered aircraft need to recognize the term in maintenance manuals and parts lists. The smell alone does not indicate the product — proper labeling and material safety information matter, since the solvent is flammable and the vapors require ventilation.
Intuition Check
Do not read “banana oil” literally. It is not made from bananas, and it is not an oil used for lubrication; it is a solvent used with certain coatings.
Example Sentence 1
The technician thinned the dope with banana oil before brushing it onto the fabric-covered wing.
Example Sentence 2
Work outdoors or under a fume hood when using banana oil to avoid breathing the concentrated vapors.