Supplied B1 Module 07A textbook: PDF pages 131–162.
Drawing purpose and types
A detail drawing defines a single part, including dimensions, material and finish. An assembly drawing shows the relationship between parts, while an installation drawing locates an assembly in the aircraft. Exploded views aid identification and sequence but are not necessarily dimensionally accurate. Use the applicable drawing type for the question being answered. A beautifully printed obsolete drawing is still unsuitable for a current task. Check revision and applicability before using any paper or electronic presentation.
Which drawing primarily shows how several parts relate to each other? An assembly drawing.
Title blocks and revision control
The title block identifies the drawing, part or assembly, drawing number, scale, units and responsible organisation. Revision information records authorised changes; notes may define general tolerances or processing requirements. Check sheet numbers and continuation references so the full instruction is available. Electronic, microfilm and microfiche copies require the same document control as paper copies. Do not add unofficial changes to a controlled drawing. If the drawing conflicts with another instruction, resolve the conflict through the approved technical process.
What should be checked before working from a drawing? Revision, applicability, units and notes.
Projections and views
Orthographic views represent the object from different directions. First-angle and third-angle projection place views differently; use the projection symbol rather than assuming a layout. An isometric view communicates three-dimensional form but does not replace specified dimensions. Section views reveal internal features by imagining the part cut at a indicated plane. Hatching identifies cut material. A detail view enlarges a local feature. Reading several views together prevents confusing a hole, recess or hidden feature with an external outline.
How should the projection convention be identified? From the drawing's projection symbol and standard.
Line conventions and dimensions
Visible outlines, hidden edges, centre lines and dimension lines communicate different information. Dimension values take precedence over measuring a print, especially after a document has been resized. A diameter symbol refers to a full circular size; a radius dimension refers to half the diameter. Read angular, surface-finish and geometrical tolerance symbols using the applicable standard. Do not assume that a displayed CAD image is a calibrated ruler. Datums establish references from which features and tolerances are related.
What governs a part size on a drawing? The stated dimension and tolerance.
ATA organisation and standards
ATA numbering organises aircraft maintenance information by system so a subject can be found consistently. ATA 24 concerns electrical power, 27 flight controls and 32 landing gear. Specification 100 is a historical document convention, with later electronic practices represented by iSpec 2200. ISO, AN, MS, NAS and MIL identifiers refer to standards or specifications, not permission to substitute hardware. Match the complete required specification and applicability when identifying a part. A similar diameter does not guarantee equivalent strength, finish or configuration.
Which ATA chapter concerns flight controls? 27.
Wiring diagrams versus schematics
A schematic emphasises how a circuit works using symbols and logical connections. A wiring diagram emphasises installed wires, identifiers, connectors, pin numbers and physical interconnections. Follow cross-references between sheets and distinguish connected junctions from crossing lines. Locate the power source, protective device, load and return path before tracing a fault. Record the exact connector and cavity; a connector's appearance is not enough to identify a terminal. Use the legend for symbols rather than importing a convention from another drawing.
Which document is most useful for installed connector and wire identification? A wiring diagram.
Apply the knowledge
Work through these examples before starting the quiz. Explain why the other choices would not meet the requirement.
A downloaded print has been scaled to fit the page. How should a hole diameter be established?
Read its stated dimension and tolerance — Resizing changes graphical scale but not the specified dimension.
Two circuits cross without the connection convention shown in the legend. What should be done?
Interpret the crossing using the drawing legend — Connection symbols depend on the controlled drawing convention.
A hardware item matches size but has a different standard number. What is correct?
Check approved interchangeability before substitution — Standards can differ in strength, finish, material and geometry.
The task refers to ATA 32. Which subject is expected?
Landing gear — ATA 32 identifies the landing-gear system.
A section view is needed to interpret an internal passage. What does it show?
Features exposed by an imaginary cutting plane — Section views communicate internal geometry.
A drawing states millimetres but a measurement is made in inches. What is essential?
Convert consistently before comparing with the limits — Units are part of the specified dimension.