Definition
A small hand saw with a narrow, tapered blade used to cut curves, circles, and irregular shapes in thin material such as aircraft plywood, fabric-covered formers, or sheet metal patterns. The thin blade allows the saw to follow tight radii that a standard saw cannot.
Plain English
A small hand saw with a thin, pointed blade made for cutting curves and rounded shapes rather than straight lines.
Context Anchor
Seen in aircraft maintenance, repair, and fabrication work when a technician needs to cut an opening or curved shape by hand.
Derivation
Called a 'compass saw' because the narrow blade can swing in a tight arc, much like a drafting compass drawing a circle. The name highlights the tool's ability to cut curved shapes.
Why Pilots Care
If you are reading a maintenance description, knowing this term helps you understand that the work involves hand-cutting a shaped opening, not using a navigation instrument.
Analogy
It is like using a small kitchen knife instead of a large bread knife when you need to cut around a tight curve.
Intuition Check
Do not read “compass” here as the cockpit instrument that shows direction. In “compass saw,” it points to curved or circular cutting.
Example Sentence 1
The mechanic used a compass saw to cut the rounded lightening hole in the wooden former.
Example Sentence 2
In the tight corner of the inspection panel, only the compass saw could make the needed cut.