Engine Inspection Oral Exam Questions and Answers
Rehearse Engine Inspection, Powerplant subject AM.III.C, by explaining what an inspection result tells you and what information you need next. Use the prompts below to practice complete spoken answers about engine condition, diagnostic checks, and procedure applicability.
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What should my answer explain?
Begin with the engine and the inspection task: a reciprocating-cylinder compression check, a turbine-engine internal view, an operational ground check, or a mount inspection. Name the observation you are trying to make before naming a tool. Then explain how you would interpret that observation using the answer and its cited FAA page.
Keep your rehearsal focused on engine inspection rather than reciting a general list of nondestructive testing methods. Practice distinguishing a measurement from a conclusion, a trend from a single reading, and a handbook illustration from instructions for a particular engine. When you check an answer, notice qualifying words such as usually, can, and should as carefully as the part names.
For the wider exam, read the Powerplant oral questions overview. Use the ACS codes guide when reviewing the ACS codes on your Airman Knowledge Test Report (AKTR).
Which ACS elements do these questions practice?
The table identifies the elements used for the practice questions below. It is not a prediction of your assigned questions.
| ACS element | Study focus |
|---|---|
| AM.III.C.K7 | Engine component inspection, checking, and servicing. |
| AM.III.C.R1 | A compression test on a reciprocating engine. |
| AM.III.C.K3 | Special inspections. |
| AM.III.C.K8 | Engine mounts, mounting hardware, and the inspection and checking of each. |
Which oral exam questions can I practice?
These practice questions are built from ACS elements; they are not actual FAA test questions. The short explanations are study answers, not complete aircraft maintenance procedures.
1. What does a cylinder compression test determine?
ACS: AM.III.C.K7
The test determines whether the valves, piston rings, and pistons adequately seal the combustion chamber. Excessive pressure leakage prevents the cylinder from developing its full power. The purpose of testing cylinder compression is to determine whether cylinder replacement is necessary.
FAA-H-8083-32B, Powerplant, p. 10-39
2. Where can escaping air indicate cylinder leakage during a compression check?
ACS: AM.III.C.K7
For cylinders below the specified minimum compression, the handbook calls for further checking to locate leakage. Air you can hear leaking at the exhaust outlet points to the exhaust valve, air escaping at the air intake points to the intake valve, and air escaping at the engine breather outlets points to leakage past the piston rings.
FAA-H-8083-32B, Powerplant, p. 10-40 · FAA-H-8083-32B, Powerplant, p. 10-41
3. What compression-test precautions does the handbook give for ignition and propeller movement?
ACS: AM.III.C.R1
Before the test, make sure the ignition switch is in the OFF position so the engine cannot fire accidentally. When you close the shutoff valve on the tester, make sure the propeller path is clear of all objects: if the piston is not on top dead center, there is enough air pressure in the combustion chamber to rotate the propeller.
FAA-H-8083-32B, Powerplant, p. 10-39 · FAA-H-8083-32B, Powerplant, p. 10-40
4. Why review previous compression-check results before interpreting a new test?
ACS: AM.III.C.K7
The handbook directs the mechanic to review the maintenance records of the engine being tested. Previous compression-check results help determine progressive wear conditions and establish the necessary maintenance actions. Read the earlier results as part of that review rather than considering only the latest cylinder reading.
FAA-H-8083-32B, Powerplant, p. 10-39
5. What does the handbook mean by a borescope for turbine-engine inspection?
ACS: AM.III.C.K7
The Powerplant handbook’s glossary defines a borescope as an inspection tool for viewing inside a turbine engine without disassembling it. In that description, a light, mirror, and magnifying lens are mounted inside a small-diameter tube. The tube is inserted through the turbine engine’s borescope inspection ports.
FAA-H-8083-32B, Powerplant, p. G-4
6. What does the reciprocating-engine ground check evaluate, beyond a magneto check?
ACS: AM.III.C.K7
The ground check evaluates engine functioning by comparing power input, measured by manifold pressure, with power output, measured by rpm or torque. After the engine is thoroughly warm, it checks the powerplant and accessories by ear, visually, and through instrument readings, control movements, and switch reactions. A satisfactory magneto check can coexist with an unsatisfactory condition elsewhere.
FAA-H-8083-32B, Powerplant, p. 10-26
7. How does the handbook describe checking a turbofan engine at idle?
ACS: AM.III.C.K7
After the engine has started, attained idle rpm, and stabilized its instrument readings, the handbook says it should be checked for satisfactory operation at idle. Oil-pressure, tachometer, and exhaust-gas-temperature readings should be compared with the allowable ranges. Consult the manufacturer’s operating instructions; the handbook’s example procedures and values do not have general application.
FAA-H-8083-32B, Powerplant, p. 10-57
8. What is turbine-engine condition monitoring looking for over time?
ACS: AM.III.C.K7
Many turbine engines use an engine-condition program to help determine engine health in service. The handbook describes monitoring certain engine parameters daily and watching for shifts or changes. This is also called trend analysis performance monitoring. A shift in key parameters over time could be a warning that the engine has serious internal deterioration and should be overhauled.
FAA-H-8083-32B, Powerplant, p. 8-2
9. Why does sudden engine stoppage call for special attention to internal condition?
ACS: AM.III.C.K3
The handbook describes sudden stoppage as a very rapid and complete engine stoppage. It can be caused by engine seizure or by one or more propeller blades striking an object so that rpm goes to zero in less than one complete revolution of the propeller. The handbook says sudden stoppage can cause internal damage, giving examples such as cracked propeller-gear teeth, gear-train damage, crankshaft flyweights becoming detuned or misaligned, and damaged propeller bearings. When sudden stoppage occurs, the engine usually requires replacement or disassembly and inspection according to the manufacturer’s instructions.
FAA-H-8083-32B, Powerplant, p. 8-1
10. What frame and bolt-hole conditions should be checked during the pre-installation engine-mount inspection?
ACS: AM.III.C.K8
In its pre-installation external-unit inspection, the handbook says the engine mounting frame should be checked for steel-tubing distortion, with examples including bends, dents, flat spots, corrosion, or cracks, and it says to use dye penetrant inspection to reveal a crack, porous area, or other defects. The mounting bolts are usually checked for condition by magnetic particle inspection or other approved processes, and while the bolts are removed, their holes should be checked for elongation caused by movement of an improperly tightened bolt.
FAA-H-8083-32B, Powerplant, p. 8-5
How do I answer it out loud?
Use three passes through this practice set. First explain cylinder sealing, leakage paths, and compression-test precautions. Next rehearse the internal-inspection and operational-check questions. Finish with trend monitoring, sudden-stoppage inspection, and the engine-mount checks. Compare each spoken answer with the source-backed explanation before moving on.
How should I check my practice answer?
Make a four-column review sheet: inspection task, observation, interpretation, and next reference to consult. Use questions 1, 6, 8, and 10 as your first rows. Close the answers and explain each row out loud. Then say the compression-test precautions from question 3 in your own words.
Check the explanation in the handbook during study, then close it for the spoken rehearsal. The ACS states that reference material is not allowed for answering oral questions.
“the applicant is not allowed to use any reference material to answer the oral questions asked by the examiner.”
What else should I know?
Why test compression soon after shutdown, and must the engine be run first?
The handbook calls for testing as soon as possible after shutdown so the piston rings, cylinder walls, and other parts are still freshly lubricated. The handbook says prior engine operation is not necessary during engine buildup or for individually replaced cylinders; in those cases, it describes adding a small quantity of lubricating oil and turning the engine over several times before testing.
Does a satisfactory magneto check rule out other engine problems?
No. The handbook says a magneto check can be satisfactory while an unsatisfactory condition is present elsewhere in the engine. The ground check evaluates the engine by comparing manifold pressure with rpm or torque, rather than relying solely on the ignition-system check.
Are the handbook’s turbine-operating values universal limits?
No. The handbook says its example procedures, pressures, temperatures, and rpm primarily serve as a guide and do not have general application. It says the manufacturer’s operating instructions should be consulted before attempting to start and operate a turbine engine.
What does spectrometric engine-oil analysis measure?
It identifies and measures microscopic particles of metallic elements, called wear metals, in parts per million by weight. Expert analysts can use those measurements as one of many tools for determining engine condition. An increase in certain metals can signal component wear or pending engine failure.
How can I rehearse the spoken answer?
DMEReady is an AI voice examiner for A&P oral practice in your phone or computer browser. You answer out loud, and it asks follow-up questions the way a DME would. After each session, the report shows what you covered, what you missed, what a complete answer includes, and where to read in the FAA handbooks. The first drill is free with no sign-up. It is an AI examiner, not a human DME. DMEReady is independent and is not affiliated with or endorsed by the FAA; it does not predict or guarantee exam results.
Start your free drillWhich guide should I read next?
Which sources support these answers?
References show the printed handbook pages. The links open the corresponding PDF pages.
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