Airframe Mechanic Certification Aircraft Structures & Materials 5

Question 1

What is the primary difference between a truss-type fuselage and a monocoque fuselage?

Accepted Answer

Truss-type relies on an internal framework of tubes or beams; monocoque relies on stressed skin

Answer

A truss-type fuselage uses welded or bolted tubes/beams for the primary structure with a non-structural skin covering, while monocoque relies on the skin itself to carry loads.

Question 2

What is the significance of 'limit load' in aircraft structural certification?

Accepted Answer

The maximum load expected in service, which the structure must carry without permanent deformation

Answer

Limit load is the maximum load anticipated in normal service operations; the structure must sustain limit load without permanent deformation.

Question 3

What condition is indicated when an aluminum surface shows white, powdery deposits?

Accepted Answer

Active aluminum oxide (surface corrosion)

Answer

White, powdery deposits on aluminum indicate aluminum oxide forming from active surface corrosion, which must be removed and treated.

Question 4

Which fastener is most appropriate for joining composite panels where galvanic corrosion with aluminum must be avoided?

Accepted Answer

Titanium fasteners

Answer

Titanium fasteners are used with carbon fiber composites because titanium is galvanically compatible with carbon fiber, preventing the galvanic corrosion that would occur with aluminum or steel fasteners.

Question 5

What is the purpose of 'drain holes' in aircraft lower skin panels and fairings?

Accepted Answer

To allow moisture to drain out and prevent corrosion-causing water accumulation

Answer

Drain holes allow trapped moisture to escape from low points in the structure, preventing corrosive water accumulation in pockets and cavities.

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Practice Test

Airframe Mechanic Certification Aircraft Structures & Materials 5