A&P - POWERPLANT ORAL (JEPPESEN)
NEWEST 2025 COMPLETE 260
QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) |
ALREADY GRADED A+
Core Domains
• Reciprocating Engine Theory and Construction
• Reciprocating Engine Systems: Lubrication, Cooling, Ignition, Fuel,
Exhaust
• Turbine Engine Theory and Construction
• Turbine Engine Systems: Fuel, Lubrication, Ignition, Starting, Exhaust
• Propellers and Propeller Systems
• Engine Inspection, Maintenance, Troubleshooting, and Overhaul
• Engine Electrical Systems, Fire Protection, and Instrumentation
Introduction
The A&P Powerplant Oral examination evaluates a candidate's comprehensive
knowledge of aircraft powerplant systems, including reciprocating and
turbine engines, propellers, and related accessories. The assessment covers
engine theory, construction, lubrication, cooling, ignition, fuel metering,
exhaust, electrical systems, and fire protection. The oral format requires
candidates to demonstrate both foundational knowledge and applied
troubleshooting skills, with FAA-designated examiners (DPEs) posing
scenario-based questions that mirror real-world maintenance situations.
Candidates must be prepared to explain not just what to do, but why,
,referencing manufacturer specifications, FAA regulations, and accepted
industry practices.
Section One: Questions 1–260
Question 1
What is the purpose of dynamic dampers on crankshafts?
A. To increase engine horsepower
B. To reduce engine vibration
C. To balance the propeller
D. To increase oil pressure
B. To reduce engine vibration
RATIONALE: Dynamic dampers are weighted devices attached to the
crankshaft that counteract torsional vibration by absorbing and dissipating
the energy of vibration, thereby reducing the amplitude of oscillation and
preventing crankshaft fatigue failure.
Question 2
What types of bearings are generally found in reciprocating engines?
A. Plain, ball, and roller bearings
B. Needle and thrust bearings only
C. Sleeve and journal bearings only
D. Ceramic and composite bearings
A. Plain, ball, and roller bearings
RATIONALE: Reciprocating aircraft engines use plain (sleeve) bearings
for main and connecting rod journals, ball bearings for some accessory drives,
and roller bearings where high radial loads are encountered.
Question 3
Are the connecting rods used in each cylinder of a radial engine the same?
Explain.
,A. Yes, all connecting rods are identical
B. No, radial engines use master and articulating rod assemblies
C. Yes, except for the number of bolts
D. No, each cylinder has a unique rod design
B. No, radial engines use master and articulating rod assemblies
RATIONALE: In a radial engine, one master rod connects directly to the
crankshaft, while the remaining cylinders use articulating rods that attach to
the master rod. This design accommodates the radial arrangement of
cylinders around a single crankpin.
Question 4
Name the different types of piston rings.
A. Compression, oil control, and oil scraper
B. Intake, exhaust, and sealing
C. Upper, middle, and lower
D. Primary, secondary, and tertiary
A. Compression, oil control, and oil scraper
RATIONALE: Piston rings are classified as compression rings (seal
combustion gases), oil control rings (regulate oil film on cylinder walls), and
oil scraper rings (scrape excess oil from cylinder walls back to the sump).
Question 5
Where should piston ring gaps be installed relative to each other, and why?
A. Aligned to allow blow-by
B. Staggered so they do not align, to prevent excessive blow-by
C. Aligned to allow oil passage
D. Randomly placed without regard to position
B. Staggered so they do not align, to prevent excessive blow-by
, RATIONALE: Compression ring gaps must be staggered so they do not
align; if gaps are aligned, combustion gases can escape directly past the rings,
causing excessive blow-by and loss of compression.
Question 6
What could result from incorrectly installed piston rings?
A. Excessive oil consumption
B. Increased compression
C. Lower oil temperature
D. Higher fuel economy
A. Excessive oil consumption
RATIONALE: Incorrectly installed piston rings—particularly oil control
rings installed upside down or with gaps aligned—can cause excessive oil
consumption as oil is not properly scraped from cylinder walls.
Question 7
What purpose do oil control rings serve?
A. They seal combustion gases
B. They regulate the thickness of the oil film on cylinder walls
C. They increase compression ratio
D. They reduce valve clearance
B. They regulate the thickness of the oil film on cylinder walls
RATIONALE: Oil control rings maintain a proper oil film on cylinder walls
for lubrication while preventing excess oil from entering the combustion
chamber, thereby controlling oil consumption.
Question 8
What is used to prevent valve surge or floating in an aircraft engine?
A. Stronger valve springs
B. Two or more springs on each valve
NEWEST 2025 COMPLETE 260
QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) |
ALREADY GRADED A+
Core Domains
• Reciprocating Engine Theory and Construction
• Reciprocating Engine Systems: Lubrication, Cooling, Ignition, Fuel,
Exhaust
• Turbine Engine Theory and Construction
• Turbine Engine Systems: Fuel, Lubrication, Ignition, Starting, Exhaust
• Propellers and Propeller Systems
• Engine Inspection, Maintenance, Troubleshooting, and Overhaul
• Engine Electrical Systems, Fire Protection, and Instrumentation
Introduction
The A&P Powerplant Oral examination evaluates a candidate's comprehensive
knowledge of aircraft powerplant systems, including reciprocating and
turbine engines, propellers, and related accessories. The assessment covers
engine theory, construction, lubrication, cooling, ignition, fuel metering,
exhaust, electrical systems, and fire protection. The oral format requires
candidates to demonstrate both foundational knowledge and applied
troubleshooting skills, with FAA-designated examiners (DPEs) posing
scenario-based questions that mirror real-world maintenance situations.
Candidates must be prepared to explain not just what to do, but why,
,referencing manufacturer specifications, FAA regulations, and accepted
industry practices.
Section One: Questions 1–260
Question 1
What is the purpose of dynamic dampers on crankshafts?
A. To increase engine horsepower
B. To reduce engine vibration
C. To balance the propeller
D. To increase oil pressure
B. To reduce engine vibration
RATIONALE: Dynamic dampers are weighted devices attached to the
crankshaft that counteract torsional vibration by absorbing and dissipating
the energy of vibration, thereby reducing the amplitude of oscillation and
preventing crankshaft fatigue failure.
Question 2
What types of bearings are generally found in reciprocating engines?
A. Plain, ball, and roller bearings
B. Needle and thrust bearings only
C. Sleeve and journal bearings only
D. Ceramic and composite bearings
A. Plain, ball, and roller bearings
RATIONALE: Reciprocating aircraft engines use plain (sleeve) bearings
for main and connecting rod journals, ball bearings for some accessory drives,
and roller bearings where high radial loads are encountered.
Question 3
Are the connecting rods used in each cylinder of a radial engine the same?
Explain.
,A. Yes, all connecting rods are identical
B. No, radial engines use master and articulating rod assemblies
C. Yes, except for the number of bolts
D. No, each cylinder has a unique rod design
B. No, radial engines use master and articulating rod assemblies
RATIONALE: In a radial engine, one master rod connects directly to the
crankshaft, while the remaining cylinders use articulating rods that attach to
the master rod. This design accommodates the radial arrangement of
cylinders around a single crankpin.
Question 4
Name the different types of piston rings.
A. Compression, oil control, and oil scraper
B. Intake, exhaust, and sealing
C. Upper, middle, and lower
D. Primary, secondary, and tertiary
A. Compression, oil control, and oil scraper
RATIONALE: Piston rings are classified as compression rings (seal
combustion gases), oil control rings (regulate oil film on cylinder walls), and
oil scraper rings (scrape excess oil from cylinder walls back to the sump).
Question 5
Where should piston ring gaps be installed relative to each other, and why?
A. Aligned to allow blow-by
B. Staggered so they do not align, to prevent excessive blow-by
C. Aligned to allow oil passage
D. Randomly placed without regard to position
B. Staggered so they do not align, to prevent excessive blow-by
, RATIONALE: Compression ring gaps must be staggered so they do not
align; if gaps are aligned, combustion gases can escape directly past the rings,
causing excessive blow-by and loss of compression.
Question 6
What could result from incorrectly installed piston rings?
A. Excessive oil consumption
B. Increased compression
C. Lower oil temperature
D. Higher fuel economy
A. Excessive oil consumption
RATIONALE: Incorrectly installed piston rings—particularly oil control
rings installed upside down or with gaps aligned—can cause excessive oil
consumption as oil is not properly scraped from cylinder walls.
Question 7
What purpose do oil control rings serve?
A. They seal combustion gases
B. They regulate the thickness of the oil film on cylinder walls
C. They increase compression ratio
D. They reduce valve clearance
B. They regulate the thickness of the oil film on cylinder walls
RATIONALE: Oil control rings maintain a proper oil film on cylinder walls
for lubrication while preventing excess oil from entering the combustion
chamber, thereby controlling oil consumption.
Question 8
What is used to prevent valve surge or floating in an aircraft engine?
A. Stronger valve springs
B. Two or more springs on each valve
