ACS Airframe Systems & Structural Maintenance 3

Question 1

Which NDT method is BEST suited for detecting subsurface delaminations in a composite honeycomb sandwich structure?

Accepted Answer

Tap test or ultrasonic through-transmission

Answer

A coin tap test or ultrasonic through-transmission is used to detect subsurface delaminations in composite honeycomb panels, while dye penetrant only finds surface defects and magnetic particle requires ferrous material.

Question 2

What is the correct procedure when stop-drilling a crack in aluminum aircraft skin?

Accepted Answer

Drill the hole just ahead of the visible crack tip

Answer

The stop-drill hole must be placed just ahead of (beyond) the visible crack tip to eliminate the stress concentration at the crack tip and arrest crack propagation.

Question 3

When replacing aircraft transparent enclosures (acrylic), the fastener holes should be:

Accepted Answer

Oversized to allow for thermal expansion of the acrylic

Answer

Acrylic plastic has a high coefficient of thermal expansion, so fastener holes must be oversized to prevent cracking as the material expands and contracts.

Question 4

Which statement about aircraft control cable tension is correct?

Accepted Answer

Tension must be set at the temperature specified, with correction applied for ambient temperature using a rigging chart

Answer

Control cable tension varies with temperature; a rigging chart must be used to apply temperature corrections so final tension is correct across the operating temperature range.

Question 5

A mechanic finds exfoliation corrosion on an aluminum alloy wing spar cap. What action is required?

Accepted Answer

Clean, treat, and determine if remaining material meets minimum thickness per SRM

Answer

Exfoliation corrosion causes layer-by-layer material loss; the mechanic must clean, treat, measure the remaining material, and compare it to the SRM minimum thickness allowable to determine airworthiness.

(ACS) Airman Certification Standard Certified Mechanic Practice Test

(ACS) Airman Certification Standard Certified Mechanic Practice Test

ACS Airframe Systems & Structural Maintenance 3