Powerplant ASA-Baker’s FAA Oral
Questions
2025/2026
Exam Prep Guide
(Actual Verified Questions and
Answers)
A+ Grade Guarantee
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
1. What is the main advantage of a horizontally The horizontally opposed engine has a
opposed engine over a radial engine for pow- much smaller frontal area and is easier
ering modern aircraft? to streamline than a radial engine.
2. How many throws are there in the crank- six
shaft of a six-cylinder horizontally opposed
engine?
3. What kind of connecting rod arrangement is A master rod connects the single throw
used in a radial engine? of the crankshaft with a piston. All other
pistons are connected to the master rod
with link rods.
4. Of what material are most piston rings gray cast iron
made?
5. What is the reason for using hydraulic valve Hydraulic lifters keep all the clearance
lifters in an aircraft engine? out of the valve operating mechanism.
This decreases the wear of the valve
train components.
6. At what speed does the camshaft turn in re- one half the speed of the crankshaft
lation to the crankshaft?
7. What kind of main bearings are used in a steel backed, lead-alloy inserts
horizontally opposed engine?
8. On what stroke is the piston when the intake exhaust stroke
valve begins to open?
9. On what stroke is the piston when the ex- power stroke
haust valve begins to close?
10.
www.stuvia.com
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
Why are both hot and cold clearances given The hot clearance is given for valve tim-
for radial engines? ing purposes. The timing is adjusted
with the valves in the number one pis-
ton adjusted with the hot clearance.
When the timing is set, all of the valves
are adjusted to their cold clearance.
11. What is meant by "cam-ground" piston? A piston that is not perfectly round.
When the piston reaches operating
temperature, the metal in the piston pin
boss expands enough that the piston
becomes perfectly round.
12. Where is the piston when the ignition spark 30 degrees before TDC
occurs?
13. What is a "full-floating" wrist pin? a wrist pin that is not clamped in either
the piston or the connecting rod. soft
metal plugs keep the floating pin from
scoring the cylinder wall.
14. Why do most engines use more than one Different springs with different diam-
spring on each valve? eter and pitch have different resonant
frequencies which minimize valve float.
15. Would excessive valve clearance cause the open late and close early
valves to open early or late?
16. What is the purpose of valve overlap? (2) Exhaust gas inertia leaving the cylinder
helps the fresh induction charge flow
into the cylinder leading to 1) better
volumetric efficiency 2) lower cylinder
temperatures.
www.stuvia.com
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
17. What types of piston rings are installed on compression rings, oil control rings, oil
the pistons? wiper rings
18. Why are some exhaust valves partially filled It melts at operating temperature.
with metallic sodium? Sloshing back and forth, it picks up
heat, transfers heat to the valve stem
which in turn transfers it to the cylinder
head.
19. What causes detonation? Excessive heat and pressure in the
cylinder causes the fuel-air mixture to
reach its critical pressure and temper-
ature which causes an explosion rather
than a controlled burn.
20. Why is a compression check important in de- The compression check determines the
termining the condition of an engine? condition of the seal between the piston
rings and the cylinder walls, and the
seal between the valves and their seats.
21. What is meant by compression ratio? The compression ratio is the volume of
the cylinder with the piston at the bot-
tom of its stroke to the top of its stroke.
22. What cylinder is engine-to magneto-timing number one cylinder
based on?
23. What are the main causes of the cylinder hav- broken rings, rings that do not seat
ing low compression? (4) properly, burnt valves, poorly seating
valves
24. What should be done to a nosewheel plane support the tail
before removing the engine?
www.stuvia.com
Questions
2025/2026
Exam Prep Guide
(Actual Verified Questions and
Answers)
A+ Grade Guarantee
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
1. What is the main advantage of a horizontally The horizontally opposed engine has a
opposed engine over a radial engine for pow- much smaller frontal area and is easier
ering modern aircraft? to streamline than a radial engine.
2. How many throws are there in the crank- six
shaft of a six-cylinder horizontally opposed
engine?
3. What kind of connecting rod arrangement is A master rod connects the single throw
used in a radial engine? of the crankshaft with a piston. All other
pistons are connected to the master rod
with link rods.
4. Of what material are most piston rings gray cast iron
made?
5. What is the reason for using hydraulic valve Hydraulic lifters keep all the clearance
lifters in an aircraft engine? out of the valve operating mechanism.
This decreases the wear of the valve
train components.
6. At what speed does the camshaft turn in re- one half the speed of the crankshaft
lation to the crankshaft?
7. What kind of main bearings are used in a steel backed, lead-alloy inserts
horizontally opposed engine?
8. On what stroke is the piston when the intake exhaust stroke
valve begins to open?
9. On what stroke is the piston when the ex- power stroke
haust valve begins to close?
10.
www.stuvia.com
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
Why are both hot and cold clearances given The hot clearance is given for valve tim-
for radial engines? ing purposes. The timing is adjusted
with the valves in the number one pis-
ton adjusted with the hot clearance.
When the timing is set, all of the valves
are adjusted to their cold clearance.
11. What is meant by "cam-ground" piston? A piston that is not perfectly round.
When the piston reaches operating
temperature, the metal in the piston pin
boss expands enough that the piston
becomes perfectly round.
12. Where is the piston when the ignition spark 30 degrees before TDC
occurs?
13. What is a "full-floating" wrist pin? a wrist pin that is not clamped in either
the piston or the connecting rod. soft
metal plugs keep the floating pin from
scoring the cylinder wall.
14. Why do most engines use more than one Different springs with different diam-
spring on each valve? eter and pitch have different resonant
frequencies which minimize valve float.
15. Would excessive valve clearance cause the open late and close early
valves to open early or late?
16. What is the purpose of valve overlap? (2) Exhaust gas inertia leaving the cylinder
helps the fresh induction charge flow
into the cylinder leading to 1) better
volumetric efficiency 2) lower cylinder
temperatures.
www.stuvia.com
, PowerplantPowerplant
ASA/Baker's School
ASA-Baker's List
School ofofFAA
List OralQuestions
FAA Oral Questions
Study online at https://quizlet.com/_hsgwz1
17. What types of piston rings are installed on compression rings, oil control rings, oil
the pistons? wiper rings
18. Why are some exhaust valves partially filled It melts at operating temperature.
with metallic sodium? Sloshing back and forth, it picks up
heat, transfers heat to the valve stem
which in turn transfers it to the cylinder
head.
19. What causes detonation? Excessive heat and pressure in the
cylinder causes the fuel-air mixture to
reach its critical pressure and temper-
ature which causes an explosion rather
than a controlled burn.
20. Why is a compression check important in de- The compression check determines the
termining the condition of an engine? condition of the seal between the piston
rings and the cylinder walls, and the
seal between the valves and their seats.
21. What is meant by compression ratio? The compression ratio is the volume of
the cylinder with the piston at the bot-
tom of its stroke to the top of its stroke.
22. What cylinder is engine-to magneto-timing number one cylinder
based on?
23. What are the main causes of the cylinder hav- broken rings, rings that do not seat
ing low compression? (4) properly, burnt valves, poorly seating
valves
24. What should be done to a nosewheel plane support the tail
before removing the engine?
www.stuvia.com
