What does "clearance" refer to in the context of aircraft drawings?

In the context of aircraft drawings, "clearance" refers to an allowable dimension between two parts. This term is critical in ensuring that components fit together properly while still providing necessary space to allow for safe operation and functionality. Clearances account for tolerances and variations during manufacturing, which can prevent parts from binding, rubbing, or experiencing undue stress.

In aerospace engineering, maintaining appropriate clearances is vital not only for mechanical operation but also for thermal expansion and contraction, ensuring that moving parts can function without interference. The concept serves as a key part of design specifications to guarantee that all components work harmoniously together within the constraints of an aircraft's structure and systems.