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Hardness tester for fire-damaged steel

Aviation Mechanic General (AMG) practice question 10 of 21 on Inspection Concepts and Techniques. ACS element AM.I.K.K5 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONAfter exposure to fire, a steel structural part shows no visible damage. Which device does the handbook identify for determining possible damage to steel structures?

  1. AA Rockwell C hardness tester
  2. BAn eddy current conductivity tester
  3. CA resonance ultrasonic thickness gauge
Show the answer and explanation

Correct answer: A. A Rockwell C hardness tester

  • A — correct Because the strength of metals is related to hardness, the handbook states that possible damage to steel structures might be determined with a hardness tester such as a Rockwell C hardness tester.
  • B — incorrect A conductivity tester using eddy current is the device the handbook names for evaluating suspect aluminum structure after fire, not steel.
  • C — incorrect Resonance ultrasonic instruments measure thickness and locate corrosion or wear; they are not identified as the means of detecting heat damage in steel.

BACKGROUND

Inspection of aircraft structure that has been subjected to fire or intense heat is straightforward when visible damage is present, since visible damage requires repair or replacement. When no visible damage is present, structural integrity may still have been compromised, because most metallic components were heat-treated during manufacture and exposure to abnormal heat can severely degrade design strength. For aluminum structure that passes visual inspection but is still suspect, a conductivity tester using eddy current is used. Since the strength of metals is related to hardness, possible damage to steel structures might be determined with a hardness tester such as a Rockwell C hardness tester.

STUDY TIP

Match the metal to the tester: aluminum after fire is checked with an eddy current conductivity tester, steel with a Rockwell C hardness tester.

KEY POINTS

  • Visible fire damage requires repair or replacement.
  • Suspect aluminum structure is evaluated with an eddy current conductivity tester.
  • Suspect steel structure may be evaluated with a Rockwell C hardness tester.

SOURCES

  • FAA-H-8083-30B ch10 "Fire Damage"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-30B Aviation Maintenance Technician Handbook – General, 14 CFR part 43 and part 65. Regulations and handbooks are revised; confirm details against the current edition.