Definition
A measurable extent of an object or space, such as length, width, height, diameter, or thickness. In aviation maintenance and engineering, dimensions are the specific measurements used to describe the size, shape, or position of a part or structure, typically expressed in inches, millimeters, or other standardized units.
Plain English
A size measurement of something — how long, wide, tall, or thick it is. When a manual gives you a dimension, it is telling you exactly how big a part or space should be.
Context Anchor
Seen on aircraft drawings, maintenance manuals, repair instructions, and parts information when a size, distance, angle, or location must be checked or built correctly.
Derivation
From the Latin dimensio, meaning a measuring out, from dimetiri (to measure off). The everyday sense of size or extent comes directly from this — a dimension is literally something that has been measured.
Why Pilots Care
Dimensions on a drawing or in a maintenance manual are not approximate. They define whether a part is airworthy, whether a repair is within tolerance, and whether a component fits its installation. Being off by a fraction can mean rejection during inspection.
Intuition Check
Do not read dimension as just a vague “size.” In aircraft work, a dimension is a specific measurement, often between exact points and sometimes with an allowed variation.
Example Sentence 1
The technician checked the dimension of the bushing against the tolerance listed in the maintenance manual before installing it.
Example Sentence 2
Maintenance recorded every wing dimension after the repair.