FAA Aviation Mechanic General (AMG)Aircraft Drawings, Weight and BalanceEasy
A technician reviewing an illustrated parts catalog sees a three-dimensional pictorial view of a landing gear strut in which the three principal axes are drawn 120° apart and all dimensions are drawn to true scale along those axes. What type of drawing is this?
- AOrthographic projection
- BIsometric drawing
- COblique drawing
- DSectional drawing
Show answer & explanationAnswer & explanation
Correct answer: B. Isometric drawing
An isometric drawing is a pictorial view drawn with the three axes spaced 120° apart, allowing true-scale measurements along each axis while giving a realistic 3-D appearance. It differs from orthographic multiview drawings, which show separate flat views rather than one pictorial view.
Why the other options are wrong
- A. Orthographic projection uses multiple separate flat views, not one pictorial view.
- C. Oblique drawings keep one face true shape but distort depth at an angle, not 120° axes.
- D. A sectional drawing shows interior detail by removing part of the object, not a pictorial axis layout.
Isometric Drawing
A pictorial drawing type with three axes spaced 120° apart, allowing true-to-scale measurement along each axis while presenting a 3-D appearance.
- Axes are 120° apart
- True dimensions along each axis
- Used for parts catalogs and assembly illustrations
Memory trick: Iso-120: three arms spread evenly like a peace sign.