A&P Powerplant Oral Exam Prep
Test Bank | Complete Questions
and Answers Study Pack
• What types of bearings are generally found in reciprocating engines?
Answer: Plain, ball and roller bearings.
• Are the connecting rods used in each cylinder of a radial engine the
same? Explain. Answer: No.
Radial engines use master and articulating rod assemblies.
• Name the different types of piston rings. Answer: Oil control
Compression
Oil scraper
• Where should piston ring gaps be installed relative to each other, and
why? Answer: Compression ring gaps should be staggered so they do
not align.
This prevents excessive blow-by.
• What could result from incorrectly installed piston rings? Answer:
Excessive oil consumption.
,• What purpose do oil control rings serve? Answer: They regulate the
thickness of the oil film on the cylinder walls.
• What is used to prevent valve surge or floating in an aircraft engine?
Answer: Two or more springs that are used on each valve.
• On engines equipped with hydraulic valve lifters, what should the
running valve clearance be? Answer: Zero
• What is the purpose of valve overlap? Answer: The allows for better
volumetric efficiency and lowers cylinder operating temperatures.
• What indications are given in the event of a leaking or open primer
while the engine is running? Answer: The engine will not idle properly.
• A cold cylinder is found when troubleshooting a running engine. What
does this indicate? Answer: No combustion in that cylinder.
• When pulling a propeller through, a hissing sound is heard, indicating
valve blow-by. What procedure should be performed next? Answer: A
compression check should be done to identify the faulty cylinder.
• What is the purpose of performing a compression test? Answer: To
determine if the valves, pistons, and rings are sealing properly
,• When an engine is overhauled, how is the total time affected? When a
engine is rebuilt, how is the operating history affected? Answer: The
total time on the engine must be continued and the time since major
overhaul is entered into the engine log.
If the manufacturer rebuilds the engine, fit is granted a zero-time status
and is considered to have no previous operating history.
• What inspections should be performed after a propeller strike without
sudden stoppage? Answer: 1. Inspect the engine mounts, crankcase, and
nose section for damage.
2. Inspect the oil and oil filters/screens for metal particles.
3. Inspect the crankshaft for cracks and misalignment.
• Name some of the precautions that should be performed prior to engine
removal. Answer: Disconnect the battery
Turn off the fuel valves
Chock the wheels
If necessary install a tail stand
• When inspecting a piston, where are cracks most likely to be found?
Answer: In those areas that are highly stressed;
Usually at the base of the piston bosses.
Inside at the junction of the bore and the walls.
The ring lands. (Grooves in the piston rings sit in)
, • What does it mean if an engine part is within "serviceable limits"?
Answer: It means that the part is within the manufacturers limits and can
be used in an engine (does not require replacement).
• What tools or instruments are used to inspect a cylinder barrel for out-
of-roundness? Answer: A dial indicator or inside micrometer is usually
used to measure the top of the cylinder and a the skirt.
A telescopic guage and micrometer can also be used.
TWO READINGS SHOULD BE TAKEN AT 90° TO EACH OTHER.
• How can a loose stud in an engine crankcase be repaired? Answer:
Remove the loose stud and inspect the hold for size and thread
condition. It may be necessary to use an oversize stud Heli-Coil insert.
• What publication is used to check an engine for normal operation?
Answer: Manufacturer's maintenance manual.
• A weak cylinder is found during a compression check. What must be
inspected? Answer: The piston rings, the valves for proper seating, a
leak or crack on the cylinder barrel.
• What purpose does an oil analysis serve? Answer: Metal particles in
the oil show Norma and abnormal wear of the engine. This helps in
evaluating the engine's internal condition.
Test Bank | Complete Questions
and Answers Study Pack
• What types of bearings are generally found in reciprocating engines?
Answer: Plain, ball and roller bearings.
• Are the connecting rods used in each cylinder of a radial engine the
same? Explain. Answer: No.
Radial engines use master and articulating rod assemblies.
• Name the different types of piston rings. Answer: Oil control
Compression
Oil scraper
• Where should piston ring gaps be installed relative to each other, and
why? Answer: Compression ring gaps should be staggered so they do
not align.
This prevents excessive blow-by.
• What could result from incorrectly installed piston rings? Answer:
Excessive oil consumption.
,• What purpose do oil control rings serve? Answer: They regulate the
thickness of the oil film on the cylinder walls.
• What is used to prevent valve surge or floating in an aircraft engine?
Answer: Two or more springs that are used on each valve.
• On engines equipped with hydraulic valve lifters, what should the
running valve clearance be? Answer: Zero
• What is the purpose of valve overlap? Answer: The allows for better
volumetric efficiency and lowers cylinder operating temperatures.
• What indications are given in the event of a leaking or open primer
while the engine is running? Answer: The engine will not idle properly.
• A cold cylinder is found when troubleshooting a running engine. What
does this indicate? Answer: No combustion in that cylinder.
• When pulling a propeller through, a hissing sound is heard, indicating
valve blow-by. What procedure should be performed next? Answer: A
compression check should be done to identify the faulty cylinder.
• What is the purpose of performing a compression test? Answer: To
determine if the valves, pistons, and rings are sealing properly
,• When an engine is overhauled, how is the total time affected? When a
engine is rebuilt, how is the operating history affected? Answer: The
total time on the engine must be continued and the time since major
overhaul is entered into the engine log.
If the manufacturer rebuilds the engine, fit is granted a zero-time status
and is considered to have no previous operating history.
• What inspections should be performed after a propeller strike without
sudden stoppage? Answer: 1. Inspect the engine mounts, crankcase, and
nose section for damage.
2. Inspect the oil and oil filters/screens for metal particles.
3. Inspect the crankshaft for cracks and misalignment.
• Name some of the precautions that should be performed prior to engine
removal. Answer: Disconnect the battery
Turn off the fuel valves
Chock the wheels
If necessary install a tail stand
• When inspecting a piston, where are cracks most likely to be found?
Answer: In those areas that are highly stressed;
Usually at the base of the piston bosses.
Inside at the junction of the bore and the walls.
The ring lands. (Grooves in the piston rings sit in)
, • What does it mean if an engine part is within "serviceable limits"?
Answer: It means that the part is within the manufacturers limits and can
be used in an engine (does not require replacement).
• What tools or instruments are used to inspect a cylinder barrel for out-
of-roundness? Answer: A dial indicator or inside micrometer is usually
used to measure the top of the cylinder and a the skirt.
A telescopic guage and micrometer can also be used.
TWO READINGS SHOULD BE TAKEN AT 90° TO EACH OTHER.
• How can a loose stud in an engine crankcase be repaired? Answer:
Remove the loose stud and inspect the hold for size and thread
condition. It may be necessary to use an oversize stud Heli-Coil insert.
• What publication is used to check an engine for normal operation?
Answer: Manufacturer's maintenance manual.
• A weak cylinder is found during a compression check. What must be
inspected? Answer: The piston rings, the valves for proper seating, a
leak or crack on the cylinder barrel.
• What purpose does an oil analysis serve? Answer: Metal particles in
the oil show Norma and abnormal wear of the engine. This helps in
evaluating the engine's internal condition.
