Powerplant FAA Question Bank with all Correct & 100%
Verified Answers |Actual Complete Exam |Already
Graded A+
1. (8001) Which statement is true regarding bearings used in high-powered reciprocating
aircraft engines? ✔Correct Answer-There is less rolling friction when ball bearings are used
than when roller bearings are employed.
2. (8002) A condition that can occur in radial engines but is unlikely to occur in horizontally
opposed engines is ✔Correct Answer-hydraulic lock.
3. (8003) Which condition would be the least likely to be caused by failed or failing engine
bearings? ✔Correct Answer-Low oil temperatures.
4. (8004) What is the principal advantage of using propeller reduction gears? ✔Correct
Answer-To enable the engine RPM to be increased with an accompanying increase in power and
allow the propeller to remain at a lower, more efficient RPM.
5. (8005) Which of the following will decrease volumetric efficiency in a reciprocating engine?
✔Correct Answer-3, 4, and 5.
6. (8006) Which of the following is a characteristic of a thrust bearing used in most radial
engines? ✔Correct Answer-Deep-groove ball.
7. (8007) Which bearing is least likely to be a roller or ball bearing? ✔Correct Answer-Master
rod bearing (radial engine).
8. (8008) The operating temperature valve clearance of a radial engine as compared to cold
valve clearance is ✔Correct Answer-greater.
9. (8009) 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.
10. (8010) The five events of a four-stroke cycle engine in the order of their occurrence are
✔Correct Answer-intake, compression, ignition, power, exhaust.
11. (8011) 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.
12. (8012) 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.
,13. (8013) Grinding the valves of a reciprocating engine to a feather edge is likely to result in
✔Correct Answer-preignition and burned valves.
14. (8014) Which statement is correct regarding engine crankshafts? ✔Correct Answer-
Moveable counterweights serve to reduce the torsional vibrations in an aircraft reciprocating
engine.
15. (8015) On which strokes are both valves on a four-stroke cycle reciprocating aircraft engine
open? ✔Correct Answer-Exhaust and intake.
16. (8016) Master rod bearings are generally what type? ✔Correct Answer-Plain.
17. (8017) The actual power delivered to the propeller of an aircraft engine is called ✔Correct
Answer-brake horsepower.
18. (8018) Cam-ground pistons are installed in some aircraft engines to ✔Correct Answer-
provide a better fit at operating temperatures.
19. (8019) Using the following information, determine how many degrees the crankshaft will
rotate with both the intake and exhaust valves seated. ✔Correct Answer-245°.
20. (8020) Some aircraft engine manufacturers equip their product with choked or taper-ground
cylinders in order to ✔Correct Answer-provide a straight cylinder bore at operating
temperatures.
21. (8021) An aircraft reciprocating engine using hydraulic valve lifters is observed to have no
clearance in its valve-operating mechanism after the minimum inlet oil and cylinder head
temperatures for takeoff have been reached. When can this condition be expected? ✔Correct
Answer-During normal operation.
22. (8022) What tool is generally used to measure the crankshaft rotation in degrees?
✔Correct Answer-Timing disk.
23. (8023) If an engine with a stroke of 6 inches is operated at 2,000 RPM, the piston movement
within the cylinder will be ✔Correct Answer-at maximum velocity 90° after TDC.
24. (8024) If the intake valve is opened too early in the cycle of operation of a four-stroke cycle
engine, it may result in ✔Correct Answer-backfiring into the induction system.
25. (8025) Some cylinder barrels are hardened by ✔Correct Answer-nitriding.
26. (8026) Which statement is correct regarding a four-stroke cycle aircraft engine? ✔Correct
Answer-The intake valve closes on the compression stroke.
,27. (8027) On which part of the cylinder walls of a normally operating engine will the greatest
amount of wear occur? ✔Correct Answer-Near the top of the cylinder.
28. (8028) During overhaul, reciprocating engine exhaust valves are checked for stretch
✔Correct Answer-with a contour or radius gauge.
29. (8029) When is the fuel/air mixture ignited in a conventional reciprocating engine?
✔Correct Answer-Shortly before the piston reaches the top of the compression stroke.
30. (8030) Ignition occurs at 28° BTDC on a certain four-stroke cycle engine, and the intake valve
opens at 15° BTDC. How many degrees of crankshaft travel after ignition does the intake valve
open? (Consider one cylinder only.) ✔Correct Answer-373°.
31. (8031) What is the purpose of the safety circlet installed on some valve stems? ✔Correct
Answer-To prevent valves from falling into the combustion chamber.
32. (8032) Valve overlap is defined as the number of degrees of crankshaft travel ✔Correct
Answer-during which both valves are off their seats.
33. (8033) The valve clearance of an engine using hydraulic lifters, when the lifters are
completely flat, or empty, should not exceed ✔Correct Answer-a specified amount above
zero.
34. (8034) If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just
closed, the piston is on the ✔Correct Answer-compression stroke.
35. (8035) How many of the following are factors in establishing the maximum compression
ratio limitations of an aircraft engine? ✔Correct Answer-Three.
36. (8036) Full-floating piston pins are those which allow motion between the pin and
✔Correct Answer-both the piston and the small end of the connecting rod.
37. (8037) The primary purpose in setting proper valve timing and overlap is to ✔Correct
Answer-obtain the best volumetric efficiency and lower cylinder operating temperatures.
38. (8038) If the hot clearance is used to set the valves when the engine is cold, what will occur
during operation of the engine? ✔Correct Answer-The valves will open late and close early.
39. (8039) The purpose of two or more valve springs in aircraft engines is to ✔Correct
Answer-eliminate valve spring surge.
40. (8040) During overhaul, the disassembled parts of an engine are usually degreased with
some form of mineral spirits solvent rather than water-mixed degreasers primarily because
, ✔Correct Answer-water-mixed degreaser residues may cause engine oil contamination in the
overhauled engine.
41. (8041) Why does the smoothness of operation of an engine increase with a greater number
of cylinders? ✔Correct Answer-The power impulses are spaced closer together.
42. (8042) Compression ratio is the ratio between the ✔Correct Answer-cylinder volume with
piston at bottom dead center and at top dead center.
43. (8043) If the crankshaft runout readings on the dial indicator are plus .002 inch and
minus .003 inch, the runout is ✔Correct Answer-.005 inch.
44. (8044) (1) Cast iron piston rings may be used in chrome-plated cylinders. ✔Correct
Answer-both No. 1 and No. 2 are true.
45. (8045) How is proper end-gap clearance on new piston rings assured during the overhaul of
an engine? ✔Correct Answer-By placing the rings in the cylinder and measuring the end-gap
with a feeler gauge.
46. (8046) The volume of a cylinder equals 70 cubic inches when the piston is at bottom center.
When the piston is at the top of the cylinder, the volume equals 10 cubic inches. What is the
compression ratio? ✔Correct Answer-7:1
47. (8047) When cleaning aluminum and magnesium engine parts, it is inadvisable to soak them
in solutions containing soap because ✔Correct Answer-some of the soap will become
impregnated in the surface of the material and subsequently cause engine oil contamination
and foaming.
48. (8048) What is the purpose of a power check on a reciprocating engine? ✔Correct
Answer-To determine satisfactory performance.
49. (8049) What will be the likely result if the piston ring gaps happen to be aligned when
performing a differential-pressure compression check on a cylinder? ✔Correct Answer-A worn
or defective ring(s) indication.
50. (8050) Which of the following will be caused by excessive valve clearance of a cylinder on a
reciprocating aircraft engine? ✔Correct Answer-Reduced valve overlap period.
51. (8051) The floating control thermostat, used on some reciprocating engine installations,
helps regulate oil temperature by ✔Correct Answer-controlling air flow through the oil cooler.
52. (8052) Which of the following would indicate a general weak-engine condition when
operated with a fixed-pitch propeller or test club? ✔Correct Answer-Lower than normal static
RPM, full throttle operation.
Verified Answers |Actual Complete Exam |Already
Graded A+
1. (8001) Which statement is true regarding bearings used in high-powered reciprocating
aircraft engines? ✔Correct Answer-There is less rolling friction when ball bearings are used
than when roller bearings are employed.
2. (8002) A condition that can occur in radial engines but is unlikely to occur in horizontally
opposed engines is ✔Correct Answer-hydraulic lock.
3. (8003) Which condition would be the least likely to be caused by failed or failing engine
bearings? ✔Correct Answer-Low oil temperatures.
4. (8004) What is the principal advantage of using propeller reduction gears? ✔Correct
Answer-To enable the engine RPM to be increased with an accompanying increase in power and
allow the propeller to remain at a lower, more efficient RPM.
5. (8005) Which of the following will decrease volumetric efficiency in a reciprocating engine?
✔Correct Answer-3, 4, and 5.
6. (8006) Which of the following is a characteristic of a thrust bearing used in most radial
engines? ✔Correct Answer-Deep-groove ball.
7. (8007) Which bearing is least likely to be a roller or ball bearing? ✔Correct Answer-Master
rod bearing (radial engine).
8. (8008) The operating temperature valve clearance of a radial engine as compared to cold
valve clearance is ✔Correct Answer-greater.
9. (8009) 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.
10. (8010) The five events of a four-stroke cycle engine in the order of their occurrence are
✔Correct Answer-intake, compression, ignition, power, exhaust.
11. (8011) 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.
12. (8012) 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.
,13. (8013) Grinding the valves of a reciprocating engine to a feather edge is likely to result in
✔Correct Answer-preignition and burned valves.
14. (8014) Which statement is correct regarding engine crankshafts? ✔Correct Answer-
Moveable counterweights serve to reduce the torsional vibrations in an aircraft reciprocating
engine.
15. (8015) On which strokes are both valves on a four-stroke cycle reciprocating aircraft engine
open? ✔Correct Answer-Exhaust and intake.
16. (8016) Master rod bearings are generally what type? ✔Correct Answer-Plain.
17. (8017) The actual power delivered to the propeller of an aircraft engine is called ✔Correct
Answer-brake horsepower.
18. (8018) Cam-ground pistons are installed in some aircraft engines to ✔Correct Answer-
provide a better fit at operating temperatures.
19. (8019) Using the following information, determine how many degrees the crankshaft will
rotate with both the intake and exhaust valves seated. ✔Correct Answer-245°.
20. (8020) Some aircraft engine manufacturers equip their product with choked or taper-ground
cylinders in order to ✔Correct Answer-provide a straight cylinder bore at operating
temperatures.
21. (8021) An aircraft reciprocating engine using hydraulic valve lifters is observed to have no
clearance in its valve-operating mechanism after the minimum inlet oil and cylinder head
temperatures for takeoff have been reached. When can this condition be expected? ✔Correct
Answer-During normal operation.
22. (8022) What tool is generally used to measure the crankshaft rotation in degrees?
✔Correct Answer-Timing disk.
23. (8023) If an engine with a stroke of 6 inches is operated at 2,000 RPM, the piston movement
within the cylinder will be ✔Correct Answer-at maximum velocity 90° after TDC.
24. (8024) If the intake valve is opened too early in the cycle of operation of a four-stroke cycle
engine, it may result in ✔Correct Answer-backfiring into the induction system.
25. (8025) Some cylinder barrels are hardened by ✔Correct Answer-nitriding.
26. (8026) Which statement is correct regarding a four-stroke cycle aircraft engine? ✔Correct
Answer-The intake valve closes on the compression stroke.
,27. (8027) On which part of the cylinder walls of a normally operating engine will the greatest
amount of wear occur? ✔Correct Answer-Near the top of the cylinder.
28. (8028) During overhaul, reciprocating engine exhaust valves are checked for stretch
✔Correct Answer-with a contour or radius gauge.
29. (8029) When is the fuel/air mixture ignited in a conventional reciprocating engine?
✔Correct Answer-Shortly before the piston reaches the top of the compression stroke.
30. (8030) Ignition occurs at 28° BTDC on a certain four-stroke cycle engine, and the intake valve
opens at 15° BTDC. How many degrees of crankshaft travel after ignition does the intake valve
open? (Consider one cylinder only.) ✔Correct Answer-373°.
31. (8031) What is the purpose of the safety circlet installed on some valve stems? ✔Correct
Answer-To prevent valves from falling into the combustion chamber.
32. (8032) Valve overlap is defined as the number of degrees of crankshaft travel ✔Correct
Answer-during which both valves are off their seats.
33. (8033) The valve clearance of an engine using hydraulic lifters, when the lifters are
completely flat, or empty, should not exceed ✔Correct Answer-a specified amount above
zero.
34. (8034) If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just
closed, the piston is on the ✔Correct Answer-compression stroke.
35. (8035) How many of the following are factors in establishing the maximum compression
ratio limitations of an aircraft engine? ✔Correct Answer-Three.
36. (8036) Full-floating piston pins are those which allow motion between the pin and
✔Correct Answer-both the piston and the small end of the connecting rod.
37. (8037) The primary purpose in setting proper valve timing and overlap is to ✔Correct
Answer-obtain the best volumetric efficiency and lower cylinder operating temperatures.
38. (8038) If the hot clearance is used to set the valves when the engine is cold, what will occur
during operation of the engine? ✔Correct Answer-The valves will open late and close early.
39. (8039) The purpose of two or more valve springs in aircraft engines is to ✔Correct
Answer-eliminate valve spring surge.
40. (8040) During overhaul, the disassembled parts of an engine are usually degreased with
some form of mineral spirits solvent rather than water-mixed degreasers primarily because
, ✔Correct Answer-water-mixed degreaser residues may cause engine oil contamination in the
overhauled engine.
41. (8041) Why does the smoothness of operation of an engine increase with a greater number
of cylinders? ✔Correct Answer-The power impulses are spaced closer together.
42. (8042) Compression ratio is the ratio between the ✔Correct Answer-cylinder volume with
piston at bottom dead center and at top dead center.
43. (8043) If the crankshaft runout readings on the dial indicator are plus .002 inch and
minus .003 inch, the runout is ✔Correct Answer-.005 inch.
44. (8044) (1) Cast iron piston rings may be used in chrome-plated cylinders. ✔Correct
Answer-both No. 1 and No. 2 are true.
45. (8045) How is proper end-gap clearance on new piston rings assured during the overhaul of
an engine? ✔Correct Answer-By placing the rings in the cylinder and measuring the end-gap
with a feeler gauge.
46. (8046) The volume of a cylinder equals 70 cubic inches when the piston is at bottom center.
When the piston is at the top of the cylinder, the volume equals 10 cubic inches. What is the
compression ratio? ✔Correct Answer-7:1
47. (8047) When cleaning aluminum and magnesium engine parts, it is inadvisable to soak them
in solutions containing soap because ✔Correct Answer-some of the soap will become
impregnated in the surface of the material and subsequently cause engine oil contamination
and foaming.
48. (8048) What is the purpose of a power check on a reciprocating engine? ✔Correct
Answer-To determine satisfactory performance.
49. (8049) What will be the likely result if the piston ring gaps happen to be aligned when
performing a differential-pressure compression check on a cylinder? ✔Correct Answer-A worn
or defective ring(s) indication.
50. (8050) Which of the following will be caused by excessive valve clearance of a cylinder on a
reciprocating aircraft engine? ✔Correct Answer-Reduced valve overlap period.
51. (8051) The floating control thermostat, used on some reciprocating engine installations,
helps regulate oil temperature by ✔Correct Answer-controlling air flow through the oil cooler.
52. (8052) Which of the following would indicate a general weak-engine condition when
operated with a fixed-pitch propeller or test club? ✔Correct Answer-Lower than normal static
RPM, full throttle operation.
