A&P POWERPLANT ORAL EXAM PREP
2026 – 150 QUESTIONS & ANSWERS
Aviation Mechanic Complete Test Bank
📋 EXAM OVERVIEW
| Detail | Information |
|:|:|
| Certification | FAA Airframe & Powerplant (A&P) Mechanic Certificate |
| Exam Type | Oral & Practical (O&P) Exam |
| Latest Update | |
| Key References | FAA-H-8083-32B, AC43.13-1B, Jeppesen, ASA |
| Topics | Reciprocating Engines, Turbine Engines, Ignition Systems, Fuel & Oil Systems,
Propellers, Engine Inspection |
SECTION 1: RECIPROCATING ENGINES – COMPONENTS & OPERATION (Questions 1–30)
QUESTION 1
What is the purpose of a crankshaft dynamic damper?
A) To increase engine power output
B) To reduce engine vibration
C) To improve fuel efficiency
D) To control engine temperature
Correct Answer: B
Rationale: Dynamic dampers on crankshafts reduce engine vibration. They are designed to
counteract torsional vibrations that can damage the crankshaft and other engine components.
QUESTION 2
What types of connecting rods are commonly found in radial engines?
A) Single-piece connecting rods only
,B) Master and articulated rod assemblies
C) Fork and blade connecting rods
D) H-beam and I-beam rods
Correct Answer: B
Rationale: Radial engines commonly use master and articulated rod assemblies. The master
rod connects directly to the crankshaft, while articulated rods connect to the master rod via
knuckle pins.
QUESTION 3
What are the different types of piston rings?
A) Compression rings only
B) Oil control rings only
C) Compression, oil control, and oil scraper rings
D) Sealing and scraper rings
Correct Answer: C
Rationale: The different types of piston rings are compression, oil control, and oil scraper rings.
Compression rings seal the combustion chamber, while oil control and scraper rings regulate oil
distribution on the cylinder walls.
QUESTION 4
What is the purpose of oil control rings?
A) To seal the combustion chamber
B) To regulate the thickness of the oil film on the cylinder wall
C) To prevent oil from entering the combustion chamber
D) To reduce friction between piston and cylinder
Correct Answer: B
Rationale: Oil control rings regulate the thickness of the oil film on the cylinder wall. They also
scrape excess oil from the cylinder walls during the piston's downward stroke.
QUESTION 5
What is the purpose of valve overlap?
A) To increase engine compression
,B) It permits better volumetric efficiency and lowers the cylinder operating temperature
C) To reduce engine noise
D) To increase fuel economy
Correct Answer: B
Rationale: Valve overlap permits better volumetric efficiency and lowers the cylinder operating
temperature. It occurs when both the intake and exhaust valves are open simultaneously at the
end of the exhaust stroke and beginning of the intake stroke.
QUESTION 6
What is the running valve clearance on engines equipped with hydraulic valve lifters?
A) 0.010 inches
B) 0.015 inches
C) Zero
D) 0.005 inches
Correct Answer: C
Rationale: The running valve clearance on engines equipped with hydraulic valve lifters is zero.
Hydraulic lifters automatically maintain zero lash, eliminating the need for manual valve
adjustments.
QUESTION 7
When troubleshooting a running engine malfunction, what does a cold cylinder indicate?
A) Fuel starvation
B) Lack of combustion in the cylinder
C) Excessive oil consumption
D) Overheating
Correct Answer: B
Rationale: A cold cylinder indicates a lack of combustion in the cylinder. This can be caused by
a faulty spark plug, ignition lead, fuel injector, or mechanical problem.
QUESTION 8
What types of bearings are in general use in reciprocating engines?
A) Ball bearings only
, B) Roller bearings only
C) Plain, ball, and roller bearings
D) Tapered bearings only
Correct Answer: C
Rationale: Plain, ball, and roller bearings are in general use in reciprocating engines. Plain
bearings (also called journal bearings) are commonly used for crankshaft and connecting rod
bearings.
QUESTION 9
Name at least one inspection that should be made after a propeller strike (not sudden
stoppage).
A) Inspect the engine mounts, crankcase, and nose section for damage
B) Inspect the oil and oil screens/filters for metal particles
C) Inspect the propeller drive shaft or crankshaft for misalignment
D) All of the above
Correct Answer: D
Rationale: After a propeller strike, the following inspections should be made: (1) Inspect the
engine mounts, crankcase, and nose section for damage; (2) Inspect the oil and oil
screens/filters for metal particles; (3) Inspect the propeller drive shaft or crankshaft for
misalignment.
QUESTION 10
How is a cylinder barrel inspected for out of roundness?
A) By visual inspection only
B) Using a cylinder bore gauge, telescopic gauge and micrometer, or inside micrometer
C) By measuring piston diameter
D) By checking ring gap only
Correct Answer: B
Rationale: A cylinder bore gauge (or a telescopic gauge and micrometer, or an inside
micrometer) can be used to measure at the top of the cylinder and also at the skirt. Two
readings should be taken, 90° to each other.
QUESTION 11
2026 – 150 QUESTIONS & ANSWERS
Aviation Mechanic Complete Test Bank
📋 EXAM OVERVIEW
| Detail | Information |
|:|:|
| Certification | FAA Airframe & Powerplant (A&P) Mechanic Certificate |
| Exam Type | Oral & Practical (O&P) Exam |
| Latest Update | |
| Key References | FAA-H-8083-32B, AC43.13-1B, Jeppesen, ASA |
| Topics | Reciprocating Engines, Turbine Engines, Ignition Systems, Fuel & Oil Systems,
Propellers, Engine Inspection |
SECTION 1: RECIPROCATING ENGINES – COMPONENTS & OPERATION (Questions 1–30)
QUESTION 1
What is the purpose of a crankshaft dynamic damper?
A) To increase engine power output
B) To reduce engine vibration
C) To improve fuel efficiency
D) To control engine temperature
Correct Answer: B
Rationale: Dynamic dampers on crankshafts reduce engine vibration. They are designed to
counteract torsional vibrations that can damage the crankshaft and other engine components.
QUESTION 2
What types of connecting rods are commonly found in radial engines?
A) Single-piece connecting rods only
,B) Master and articulated rod assemblies
C) Fork and blade connecting rods
D) H-beam and I-beam rods
Correct Answer: B
Rationale: Radial engines commonly use master and articulated rod assemblies. The master
rod connects directly to the crankshaft, while articulated rods connect to the master rod via
knuckle pins.
QUESTION 3
What are the different types of piston rings?
A) Compression rings only
B) Oil control rings only
C) Compression, oil control, and oil scraper rings
D) Sealing and scraper rings
Correct Answer: C
Rationale: The different types of piston rings are compression, oil control, and oil scraper rings.
Compression rings seal the combustion chamber, while oil control and scraper rings regulate oil
distribution on the cylinder walls.
QUESTION 4
What is the purpose of oil control rings?
A) To seal the combustion chamber
B) To regulate the thickness of the oil film on the cylinder wall
C) To prevent oil from entering the combustion chamber
D) To reduce friction between piston and cylinder
Correct Answer: B
Rationale: Oil control rings regulate the thickness of the oil film on the cylinder wall. They also
scrape excess oil from the cylinder walls during the piston's downward stroke.
QUESTION 5
What is the purpose of valve overlap?
A) To increase engine compression
,B) It permits better volumetric efficiency and lowers the cylinder operating temperature
C) To reduce engine noise
D) To increase fuel economy
Correct Answer: B
Rationale: Valve overlap permits better volumetric efficiency and lowers the cylinder operating
temperature. It occurs when both the intake and exhaust valves are open simultaneously at the
end of the exhaust stroke and beginning of the intake stroke.
QUESTION 6
What is the running valve clearance on engines equipped with hydraulic valve lifters?
A) 0.010 inches
B) 0.015 inches
C) Zero
D) 0.005 inches
Correct Answer: C
Rationale: The running valve clearance on engines equipped with hydraulic valve lifters is zero.
Hydraulic lifters automatically maintain zero lash, eliminating the need for manual valve
adjustments.
QUESTION 7
When troubleshooting a running engine malfunction, what does a cold cylinder indicate?
A) Fuel starvation
B) Lack of combustion in the cylinder
C) Excessive oil consumption
D) Overheating
Correct Answer: B
Rationale: A cold cylinder indicates a lack of combustion in the cylinder. This can be caused by
a faulty spark plug, ignition lead, fuel injector, or mechanical problem.
QUESTION 8
What types of bearings are in general use in reciprocating engines?
A) Ball bearings only
, B) Roller bearings only
C) Plain, ball, and roller bearings
D) Tapered bearings only
Correct Answer: C
Rationale: Plain, ball, and roller bearings are in general use in reciprocating engines. Plain
bearings (also called journal bearings) are commonly used for crankshaft and connecting rod
bearings.
QUESTION 9
Name at least one inspection that should be made after a propeller strike (not sudden
stoppage).
A) Inspect the engine mounts, crankcase, and nose section for damage
B) Inspect the oil and oil screens/filters for metal particles
C) Inspect the propeller drive shaft or crankshaft for misalignment
D) All of the above
Correct Answer: D
Rationale: After a propeller strike, the following inspections should be made: (1) Inspect the
engine mounts, crankcase, and nose section for damage; (2) Inspect the oil and oil
screens/filters for metal particles; (3) Inspect the propeller drive shaft or crankshaft for
misalignment.
QUESTION 10
How is a cylinder barrel inspected for out of roundness?
A) By visual inspection only
B) Using a cylinder bore gauge, telescopic gauge and micrometer, or inside micrometer
C) By measuring piston diameter
D) By checking ring gap only
Correct Answer: B
Rationale: A cylinder bore gauge (or a telescopic gauge and micrometer, or an inside
micrometer) can be used to measure at the top of the cylinder and also at the skirt. Two
readings should be taken, 90° to each other.
QUESTION 11
