A&P POWERPLANT ORAL LATEST ACTUAL
EXAM 2025-2026 GRADED A+ WITH
COMPLETE QUESTIONS AND CORRECT
ANSWERS
What is the running valve clearance on engines equipped with
hydraulic valve lifters Correct Answer Zero
When troubleshooting a running engine malfunction, what does a
cold cylinder indicate? Correct Answer Lack of combustion in that
cylinder.
What factors about the condition of an engine can be learned by
studying the results of a compression test? Correct Answer The
results of a compression test determine if the valves, piston rings,
and pistons are adequately sealing.
What should be done to repair a loose stud in an engine
crankcase? Correct Answer Remove the loose stud, and inspect
the hole for size and the condition of the threads. It may be
necessary to use a suitable oversize stud.
What procedure should be followed when valve blow-by is
indicated by a hissing sound on a reciprocating engine when
pulling the propeller through? Correct Answer Perform a cylinder
compression test to identify the faulty cylinder
,How is a cylinder barrel inspected for out of roundness? Correct
Answer A dial indicator can be used to measure at the top of the
cylinder and also at the skirt. Two readings should be taken, 90
degrees to each other.
What type of connecting rods are commonly found in redial
engines? Correct Answer Master and articulated rod assemblies.
What are the different types of piston rings? Correct Answer
Compression, oil control, and oil scraper.
What is the purpose of oil control rings? Correct Answer Oil
control rings regulate the thickness of the oil film on the cylinder
wall.
What types of bearings are in general use in reciprocating
engines? Correct Answer Plain, ball, and roller.
Where are cracks most likely to be found in a piston? Correct
Answer Highly stressed areas; the base of the pin bosses, inside
at the junction of the head and walls, and the ring lands.
Which statements is true regarding bearings used in high-
powered reciprocating aircraft engines? Correct Answer There is
,rolling friction when ball bearings are used than when roller
bearings are employed
A condition that can occur in radial engines but is unlikely to occur
in horizontally opposed engines is Correct Answer hydraulic lock
Which condition would be caused by failed or failing engine
bearings? Correct Answer Excessive oil consumption and High oil
temperatures
What is the principal advantage of using propeller reduction
gears? Correct Answer To enable the engine RPM to be
increased with increase in power and allow the propeller to
remain at a lower, more efficient RPM
What will decrease volumetric efficienct in a reciprocating engine?
Correct Answer improper valve timing, sharp bends in the
induction system, and high carburetor air temperatures
Characteristic of a thrust bearing used in most radial engines?
Correct Answer Deep-groove ball bearing
What bearing is least likely to be a roller or ball bearing? Correct
Answer Master rod bearing (radial engine)
, The operating temperature valve clearance of a radial engine as
compared to cold valve clearance is Correct Answer greater
A nine-cylinder engine with a bore of 5.5 inches and a stroke of 6
inches will have a total piston displacement of Correct Answer
1,283 cubic inches
The five events of a four-stroke cycle engine in the order of their
occurrence are Correct Answer intake, compression, ignition,
power, exhaust
The primary concern in establishing the firing order for an
opposed engine is to Correct Answer provide for balance and
eliminate vibration to the greatest extent possible
If fuel/air ratio is proper and ignition timing is correct, the
combustion process should be completed Correct Answer just
after top center at the beginning of the power stroke
Grinding the valves of a reciprocating engine to a feather edge is
likely to result in Correct Answer preignition and burned valves
Which statement is correct regarding engine crankshafts? Correct
Answer Moveable counterweights serve to reduce the torsional
vibrations in an aircraft reciprocating engine
EXAM 2025-2026 GRADED A+ WITH
COMPLETE QUESTIONS AND CORRECT
ANSWERS
What is the running valve clearance on engines equipped with
hydraulic valve lifters Correct Answer Zero
When troubleshooting a running engine malfunction, what does a
cold cylinder indicate? Correct Answer Lack of combustion in that
cylinder.
What factors about the condition of an engine can be learned by
studying the results of a compression test? Correct Answer The
results of a compression test determine if the valves, piston rings,
and pistons are adequately sealing.
What should be done to repair a loose stud in an engine
crankcase? Correct Answer Remove the loose stud, and inspect
the hole for size and the condition of the threads. It may be
necessary to use a suitable oversize stud.
What procedure should be followed when valve blow-by is
indicated by a hissing sound on a reciprocating engine when
pulling the propeller through? Correct Answer Perform a cylinder
compression test to identify the faulty cylinder
,How is a cylinder barrel inspected for out of roundness? Correct
Answer A dial indicator can be used to measure at the top of the
cylinder and also at the skirt. Two readings should be taken, 90
degrees to each other.
What type of connecting rods are commonly found in redial
engines? Correct Answer Master and articulated rod assemblies.
What are the different types of piston rings? Correct Answer
Compression, oil control, and oil scraper.
What is the purpose of oil control rings? Correct Answer Oil
control rings regulate the thickness of the oil film on the cylinder
wall.
What types of bearings are in general use in reciprocating
engines? Correct Answer Plain, ball, and roller.
Where are cracks most likely to be found in a piston? Correct
Answer Highly stressed areas; the base of the pin bosses, inside
at the junction of the head and walls, and the ring lands.
Which statements is true regarding bearings used in high-
powered reciprocating aircraft engines? Correct Answer There is
,rolling friction when ball bearings are used than when roller
bearings are employed
A condition that can occur in radial engines but is unlikely to occur
in horizontally opposed engines is Correct Answer hydraulic lock
Which condition would be caused by failed or failing engine
bearings? Correct Answer Excessive oil consumption and High oil
temperatures
What is the principal advantage of using propeller reduction
gears? Correct Answer To enable the engine RPM to be
increased with increase in power and allow the propeller to
remain at a lower, more efficient RPM
What will decrease volumetric efficienct in a reciprocating engine?
Correct Answer improper valve timing, sharp bends in the
induction system, and high carburetor air temperatures
Characteristic of a thrust bearing used in most radial engines?
Correct Answer Deep-groove ball bearing
What bearing is least likely to be a roller or ball bearing? Correct
Answer Master rod bearing (radial engine)
, The operating temperature valve clearance of a radial engine as
compared to cold valve clearance is Correct Answer greater
A nine-cylinder engine with a bore of 5.5 inches and a stroke of 6
inches will have a total piston displacement of Correct Answer
1,283 cubic inches
The five events of a four-stroke cycle engine in the order of their
occurrence are Correct Answer intake, compression, ignition,
power, exhaust
The primary concern in establishing the firing order for an
opposed engine is to Correct Answer provide for balance and
eliminate vibration to the greatest extent possible
If fuel/air ratio is proper and ignition timing is correct, the
combustion process should be completed Correct Answer just
after top center at the beginning of the power stroke
Grinding the valves of a reciprocating engine to a feather edge is
likely to result in Correct Answer preignition and burned valves
Which statement is correct regarding engine crankshafts? Correct
Answer Moveable counterweights serve to reduce the torsional
vibrations in an aircraft reciprocating engine
