ASA POWERPLANT ORAL STUDYGUIDE
EXAM (ACTUAL EXAM) WITH CORRECT
QUESTIONS AND WELL ANSWERED
ANSWERS LATEST WELL GRADED A+ 2025
– 2026
What are the two types of thrust reversers that are used on
turbojet engines? - ANSWERS-The mechanical blockage-type
and the aerodynamic blockage-type
What is meant by trimming a turbojet engine? - ANSWERS-
Adjusting the fuel control to get the correct idling and
maximum-thrust RPM
What determines whether or not a 100-hour inspection is
required for an aircraft? - ANSWERS-100-hour inspections
are required only on aircraft that carry persons for hire or
are used to give flight instruction for hire
,Where can you find a list of items that should be inspected
on a 100-hour and an annual inspection of an aircraft
engine? - ANSWERS-in Appendix D of 14 CFR Part 43
In what publication can a mechanic find the operating
limitations for an aircraft engine? - ANSWERS-In the TCDS
for the engine
Who is authorized to perform the powerplant inspection
that is required for an annual inspection? - ANSWERS-An
A&P mechanic who holds an IA
What are two types of compression checks that can be
performed on an aircraft reciprocating engine? - ANSWERS-
A differential compression check and a direct compression
check
At what speed does the camshaft turn, relative to the
crankshaft speed in a horizontally opposed engine? -
ANSWERS-The camshaft turns at one half of the crankshaft
speed
,What kind of main bearings are used in a horizontally
opposed engine? - ANSWERS-Steel-backed, lead-alloy
bearing inserts
On what stroke is the piston of a reciprocating engine when
the intake valve begins to open? - ANSWERS-On the exhaust
stroke
On what stroke is the piston of a reciprocating engine when
the exhaust valve begins to open? - ANSWERS-On the power
stroke
Why are both the hot and cold valve clearances give for
most radial engine? - ANSWERS-The hot clearance is given
for valve timing purposes. The timing is adjusted with the
valves in cylinder number one, set with the hot clearance.
When the timing is set, all of the valves are adjusted to their
cold clearance.
What is meant by a cam-ground piston? - ANSWERS-A
piston that is not perfectly round. Its dimension parallel
with the wrist pin is several thousandths of an inch less than
its dimension perpendicular to the wrist pin. When the
piston reaches operating temperature, the metal in the
, piston pin boss expands enough that the piston becomes
perfectly round
Where is the piston in a reciprocating engine when the
ignition spark occurs? - ANSWERS-About 30 degrees of
crankshaft rotation before the piston reaches top center on
the compression stroke
What is meant by a full-floating wrist pin? - ANSWERS-A
wrist pin that is not clamped in either the piston or the
connecting rod. Full-floating wrist pins are kept from scoring
the cylinder walls by soft metal plugs in their ends
Why do most aircraft reciprocating engines use more than
one spring on each valve? - ANSWERS-By using more than
one spring and having the wire diameter and pitch of the
springs different, valve float is minimized. The springs have
different resonant frequencies, so at least one spring will
always be exerting a force on the valve
What is the main advantage of a horizontally opposed
engine over a radial engine for powering modern aircraft? -
ANSWERS-The horizontally opposed engine has a much
smaller frontal area and is easier to streamline than a radial
engine
EXAM (ACTUAL EXAM) WITH CORRECT
QUESTIONS AND WELL ANSWERED
ANSWERS LATEST WELL GRADED A+ 2025
– 2026
What are the two types of thrust reversers that are used on
turbojet engines? - ANSWERS-The mechanical blockage-type
and the aerodynamic blockage-type
What is meant by trimming a turbojet engine? - ANSWERS-
Adjusting the fuel control to get the correct idling and
maximum-thrust RPM
What determines whether or not a 100-hour inspection is
required for an aircraft? - ANSWERS-100-hour inspections
are required only on aircraft that carry persons for hire or
are used to give flight instruction for hire
,Where can you find a list of items that should be inspected
on a 100-hour and an annual inspection of an aircraft
engine? - ANSWERS-in Appendix D of 14 CFR Part 43
In what publication can a mechanic find the operating
limitations for an aircraft engine? - ANSWERS-In the TCDS
for the engine
Who is authorized to perform the powerplant inspection
that is required for an annual inspection? - ANSWERS-An
A&P mechanic who holds an IA
What are two types of compression checks that can be
performed on an aircraft reciprocating engine? - ANSWERS-
A differential compression check and a direct compression
check
At what speed does the camshaft turn, relative to the
crankshaft speed in a horizontally opposed engine? -
ANSWERS-The camshaft turns at one half of the crankshaft
speed
,What kind of main bearings are used in a horizontally
opposed engine? - ANSWERS-Steel-backed, lead-alloy
bearing inserts
On what stroke is the piston of a reciprocating engine when
the intake valve begins to open? - ANSWERS-On the exhaust
stroke
On what stroke is the piston of a reciprocating engine when
the exhaust valve begins to open? - ANSWERS-On the power
stroke
Why are both the hot and cold valve clearances give for
most radial engine? - ANSWERS-The hot clearance is given
for valve timing purposes. The timing is adjusted with the
valves in cylinder number one, set with the hot clearance.
When the timing is set, all of the valves are adjusted to their
cold clearance.
What is meant by a cam-ground piston? - ANSWERS-A
piston that is not perfectly round. Its dimension parallel
with the wrist pin is several thousandths of an inch less than
its dimension perpendicular to the wrist pin. When the
piston reaches operating temperature, the metal in the
, piston pin boss expands enough that the piston becomes
perfectly round
Where is the piston in a reciprocating engine when the
ignition spark occurs? - ANSWERS-About 30 degrees of
crankshaft rotation before the piston reaches top center on
the compression stroke
What is meant by a full-floating wrist pin? - ANSWERS-A
wrist pin that is not clamped in either the piston or the
connecting rod. Full-floating wrist pins are kept from scoring
the cylinder walls by soft metal plugs in their ends
Why do most aircraft reciprocating engines use more than
one spring on each valve? - ANSWERS-By using more than
one spring and having the wire diameter and pitch of the
springs different, valve float is minimized. The springs have
different resonant frequencies, so at least one spring will
always be exerting a force on the valve
What is the main advantage of a horizontally opposed
engine over a radial engine for powering modern aircraft? -
ANSWERS-The horizontally opposed engine has a much
smaller frontal area and is easier to streamline than a radial
engine
