A detail view shows only a part of the object but in greater detail and to a larger scale than the principal view. The part that is shown in detail elsewhere on the drawing is usually encircled by a heavy line on the principal view. Figure 2-15 is an example of the use of detail views.
The principal view shows the complete control wheel, while the detail view is an enlarged drawing of a portion of the control wheel.
A pictorial drawing [Figure 2-16] is similar to a photograph. It shows an object as it appears to the eye, but it is not satisfactory for showing complex forms and shapes. Pictorial drawings are useful in showing the general appearance of an object and are used extensively with orthographic projection drawings. Pictorial drawings are used in maintenance, overhaul, and part numbers. Three types of pictorial drawings are used frequently by aircraft engineers and technicians: (1) perspective, (2) isometric, and (3) oblique.
A perspective view [Figure 2-17(a)] shows an object as it appears to an observer. It most closely resembles the way an object would look in a photograph. Because of perspective, some of the lines of an object are not parallel and therefore the actual angles and dimensions are not accurate.
An isometric view [Figure 2-17(b)] uses a combination of the views of an orthographic projection and tilts the object forward so that portions of all three views can be seen in one view. This provides the observer with a three-dimensional view of the object. Unlike a perspective drawing where lines converge and dimensions are not true, lines in an isometric drawing are parallel and dimensioned as they are in an orthographic projection.
An oblique view [Figure 2-17(c)] is similar to an isometric view except for one distinct difference. In an oblique drawing, two of the three drawing axes are always at right angles to each other.
Exploded View Drawings
An exploded view drawing is a pictorial drawing of two or more parts that fit together as an assembly. The view shows the individual parts and their relative position to the other parts before they are assembled.