What does "clearance" refer to in aircraft drawings?

In the context of aircraft drawings, "clearance" specifically refers to the dimension for fits between moving parts. This means it involves the necessary space that allows components to move freely without interference. It ensures that moving parts can operate effectively without risk of binding or damage due to contact.

Proper clearance is crucial for maintaining the aircraft's functionality and safety, particularly in systems where parts have to rotate or slide relative to one another, such as in engine components or control surfaces.

The other options, while related to dimensions and sizes of parts, do not accurately define "clearance" as it specifically pertains to the gaps required for moving parts. Overall dimensions and maximum size pertain more to the size and scale of a part, while the distance from a part to an obstruction is concerned with spatial relationships but doesn't focus specifically on the allowances required for the operation of moving components.