How is "tolerance" defined in the context of aircraft drawings?

In the context of aircraft drawings, "tolerance" refers to the permissible limits of variation in a physical dimension. It represents how much a particular dimension on a part can deviate from its specified measurement while still being acceptable for proper function and assembly. Therefore, tolerance is defined as the sum of plus and minus allowance figures for a dimension. This means if a part is designed to be a certain length, there is an upper and lower limit within which the actual length can vary, ensuring that parts can fit together correctly and operate as intended. Such precision is crucial in aviation to ensure safety, performance, and reliability.