A&P Powerplant Oral Exam Prep
Test Bank | Comprehensive
Questions and Answers Guide
‣ What types of bearings are generally found in reciprocating engines? -
✓✓Plain, ball and roller bearings.
‣ Are the connecting rods used in each cylinder of a radial engine the
same? Explain. -✓✓No. Radial engines use master and articulating rod
assemblies.
‣ Name the different types of piston rings. -✓✓Oil control, compression,
and oil scraper.
‣ Where should piston ring gaps be installed relative to each other, and
why? -✓✓Compression ring gaps should be staggered so that they do
not align. This prevents excessive blow-by.
‣ What could result from incorrectly installed piston rings? -
✓✓Excessive oil consumption.
‣ What purpose do oil control rings serve? -✓✓They regulate the
thickness of the oil film on the cylinder walls.
,‣ What is used to help prevent valve surge or floating in an aircraft
engine? -✓✓Two or more springs are used on each valve.
‣ On engines equipped with hydraulic valve lifters, what should the
running valve clearance be? -✓✓Zero.
‣ What is the purpose of valve overlap? -✓✓It allows 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? -✓✓The engine will not idle properly.
‣ A cold cylinder is found when troubleshooting a running engine. What
does this indicate? -✓✓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? -✓✓A
compression check should be performed to identify the faulty cylinder.
‣ What is the purpose of performing a compression test? -✓✓To
determine if the valves, pistons, and rings are sealing properly
‣ When an engine is overhauled, how is the total time affected? When an
engine is rebuilt, how is its operating history affected? -✓✓The total
time on the engine must be continued and the time since major overhaul
, is entered into the engine log. It the manufacturer rebuilds the engine, it
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? -✓✓1.Inspect engine mounts, the crankcase, and the
nose section for damage.
2.Inspect the oil and oil filters/screens for metal particles.
3.Inspect the crankshaft or driveshaft for cracks and misalignment.
‣ Name some of the precautions that should be performed prior to engine
removal. -✓✓Disconnect the battery, turn off the fuel valves, chock the
wheels, and if necessary, install a tail stand.
‣ When inspecting a piston, where are cracks most likely to be found? -
✓✓In those areas that are highly stressed; usually the base of the piston
bosses, inside at the junction of the bore and the walls, and the ring
lands.
‣ What does it mean if an engine part is within "serviceable limits"? -
✓✓It means that the part is within the manufacturer's 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? -✓✓A dial indicator or an inside micrometer is usually
used to measure the top of the cylinder and at the skirt. A telescopic
Test Bank | Comprehensive
Questions and Answers Guide
‣ What types of bearings are generally found in reciprocating engines? -
✓✓Plain, ball and roller bearings.
‣ Are the connecting rods used in each cylinder of a radial engine the
same? Explain. -✓✓No. Radial engines use master and articulating rod
assemblies.
‣ Name the different types of piston rings. -✓✓Oil control, compression,
and oil scraper.
‣ Where should piston ring gaps be installed relative to each other, and
why? -✓✓Compression ring gaps should be staggered so that they do
not align. This prevents excessive blow-by.
‣ What could result from incorrectly installed piston rings? -
✓✓Excessive oil consumption.
‣ What purpose do oil control rings serve? -✓✓They regulate the
thickness of the oil film on the cylinder walls.
,‣ What is used to help prevent valve surge or floating in an aircraft
engine? -✓✓Two or more springs are used on each valve.
‣ On engines equipped with hydraulic valve lifters, what should the
running valve clearance be? -✓✓Zero.
‣ What is the purpose of valve overlap? -✓✓It allows 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? -✓✓The engine will not idle properly.
‣ A cold cylinder is found when troubleshooting a running engine. What
does this indicate? -✓✓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? -✓✓A
compression check should be performed to identify the faulty cylinder.
‣ What is the purpose of performing a compression test? -✓✓To
determine if the valves, pistons, and rings are sealing properly
‣ When an engine is overhauled, how is the total time affected? When an
engine is rebuilt, how is its operating history affected? -✓✓The total
time on the engine must be continued and the time since major overhaul
, is entered into the engine log. It the manufacturer rebuilds the engine, it
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? -✓✓1.Inspect engine mounts, the crankcase, and the
nose section for damage.
2.Inspect the oil and oil filters/screens for metal particles.
3.Inspect the crankshaft or driveshaft for cracks and misalignment.
‣ Name some of the precautions that should be performed prior to engine
removal. -✓✓Disconnect the battery, turn off the fuel valves, chock the
wheels, and if necessary, install a tail stand.
‣ When inspecting a piston, where are cracks most likely to be found? -
✓✓In those areas that are highly stressed; usually the base of the piston
bosses, inside at the junction of the bore and the walls, and the ring
lands.
‣ What does it mean if an engine part is within "serviceable limits"? -
✓✓It means that the part is within the manufacturer's 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? -✓✓A dial indicator or an inside micrometer is usually
used to measure the top of the cylinder and at the skirt. A telescopic
