AM Blueprint Reading & Interpretation 3

Question 1

On an aircraft wiring diagram, what does a circle with an 'X' inside typically represent?

Accepted Answer

A lamp or light bulb

Answer

In aircraft wiring diagrams, a circle with an X inside is the standard symbol for a lamp or light bulb.

Question 2

What is the meaning of the abbreviation 'REF' placed next to a dimension on an engineering drawing?

Accepted Answer

The dimension is for reference only and does not control manufacturing

Answer

A REF dimension is provided for information only; it is not used to inspect the part or control manufacturing tolerances.

Question 3

In aircraft blueprint reading, what does the term 'DATUM' refer to?

Accepted Answer

A fixed reference plane or point from which measurements are taken

Answer

A datum is an exact theoretical reference plane, axis, or point established on a drawing from which all feature locations are measured.

Question 4

An aircraft hydraulic schematic shows a triangle pointing toward a line. What does this symbol represent?

Accepted Answer

A check valve allowing flow in one direction only

Answer

A solid triangle (arrowhead) pointing in the direction of permitted flow represents a check valve in hydraulic and pneumatic schematics.

Question 5

What does 'CRES' stand for in aircraft material callouts on drawings?

Accepted Answer

Corrosion Resistant Steel

Answer

CRES is the abbreviation for Corrosion Resistant Steel, commonly used in aircraft structural and fluid system components.

(AM) Aircraft Maintenance Certification Practice Test