Airframe and Powerplant (A&P) Oral and
Practical EXAM STUDY GUIDE 2026/2027
ACCURATE QUESTIONS WITH CORRECT
DETAILED SOLUTIONS ||
100% GUARANTEED PASS
<NEWEST VERSION>
1. What is the purpose of dynamic dampers on crankshafts? - ANSWER ✔
They reduce engine vibration.
2. What types of bearings are generally found in reciprocating engines? -
ANSWER ✔ Plain, ball and roller bearings.
3. Are the connecting rods used in each cylinder of a radial engine the same?
Explain. - ANSWER ✔ No. Radial engines use master and articulating rod
assemblies.
4. Name the different types of piston rings. - ANSWER ✔ Oil control,
compression, and oil scraper.
5. Where should piston ring gaps be installed relative to each other, and why? -
ANSWER ✔ Compression ring gaps should be staggered so that they do
not align. This prevents excessive blow-by.
6. What could result from incorrectly installed piston rings? - ANSWER ✔
Excessive oil consumption.
7. What purpose do oil control rings serve? - ANSWER ✔ They regulate the
thickness of the oil film on the cylinder walls.
,8. What is done to ensure that each generator shares the load in a multiple
generator system? - ANSWER ✔ The generators are paralleled.
9. Where would you find generator rating and performance data? - ANSWER
✔ On the data plate attached to the generator.
10.How is the voltage of a DC generator controlled? - ANSWER ✔ By
varying the field current strength
11.What is the most common type of alternator used in most aircraft AC
systems? - ANSWER ✔ The three phase alternator.
12.How does the voltage regulator control the voltage of an alternator? -
ANSWER ✔ By regulating the voltage output of the DC exciter.
13.What does the speed of rotation and number of poles of an alternator
determine? - ANSWER ✔ The frequency of the alternator output.
14.What are some of the methods used to maintain 400 Hertz alternator output
frequency on large turbojet or turbofan engines? - ANSWER ✔ Constant
speed drives, integrated drive generators, and variable speed constant
frequency (VSCF) power systems.
15.Name the major parts of a DC motor. - ANSWER ✔ The armature, field,
brushes, and frame assembly.
16.Name the components of a direct cranking electric starter system. -
ANSWER ✔ An electric motor, reduction gears, and an automatic
engaging and disengaging mechanism.
17.Name three types of DC motors. - ANSWER ✔ Series, shunt and
compound.
18.What type of DC motor is commonly used for a reciprocating engine starter
and why? - ANSWER ✔ A series wound motor is commonly used because
it has a high starting torque under heavy load conditions.
,19.What are the operating modes of a turbine engine starter generator? -
ANSWER ✔ It operates first as a starter, then as a generator once the
engine is running.
20.What is a possible indication when a starter drags? - ANSWER ✔ A dirty
or worn starter commutator.
21.Where would wire with high temperature insulation material be used? -
ANSWER ✔ When they run close to high temperature areas such as
exhaust stacks or heating ducts.
22.What is the size standard for electrical wire used in US manufactured
aircraft? - ANSWER ✔ The American Wire Gauge (AWG).
23.How are wire sizes represented? - ANSWER ✔ By a numbered gauge size.
The smaller wires are represented by larger numbers. The smallest size wire
normally used in aircraft is 22-gauge.
24.What is the maximum slack allowed between the supports of a single wire or
bundle installation? - ANSWER ✔ Not over 1/2 inch deflection.
25.Why are wires bonded on powerplant installations? - ANSWER ✔ To
provide a current return path for electrical accessories, and to prevent static
discharge.
26.A reciprocating engine is found to have excessive oil consumption without
evidence of any oil leaks. What is the likely cause? - ANSWER ✔ The
piston rings are worn or broken.
27.What are the functions of lubricating oil in reciprocating engines? -
ANSWER ✔ To reduce friction between moving parts and remove heat.
28.What type of transparent plastic material is used for most aircraft
windshields? - ANSWER ✔ Acrylic plastic.
29.How should sheets of transparent plastic material be stored? - ANSWER ✔
Leave the protective paper on the material and store it tilted approximately
10° from the vertical.
, 30.How tight should the screws be tightened when installing an acrylic
windshield in a channel? - ANSWER ✔ Tighten the screw to a firm fit and
back it off one full turn.
31.What is meant by crazing of transparent plastic material? - ANSWER ✔
Tiny hair-like cracks that may not extend all of the way to the surface.
Crazing is caused by stresses or chemical fumes.
32.What type of material is used to remove surface damage to a piece of acrylic
resin? - ANSWER ✔ Micro-Mesh® abrasive sheets.
33.What are the two fuel gases most generally used for gas welding? -
ANSWER ✔ Oxygen and acetylene.
34.What fuel gases are used for welding aluminum? - ANSWER ✔ Oxygen
and hydrogen.
35.What are two types of torches used in gas welding? - ANSWER ✔
Balanced-pressure torches and injector torches.
36.What color lenses are used for gas welding steel? - ANSWER ✔ Green or
brown.
37.What color lenses are used for gas welding aluminum? - ANSWER ✔
Blue.
38.Why is it important that the pressure of the gas in acetylene cylinder be kept
low? - ANSWER ✔ Acetylene gas becomes unstable when it is kept under
pressure of more than about 15 psi.
39.What determines the amount of heat that is put into a weld by an oxy-
acetylene torch? - ANSWER ✔ The size of the orfice in the torch tip.
40.What is the difference in the appearance of an oxidizing flame, a neutral
flame, and a reducing flame produced by an oxy-acetylene torch? -
ANSWER ✔ An oxidizing flame has a pointed inner cone, and the torch
makes a hissing noise. A neutral flame has a rounded inner cone, and there is
Practical EXAM STUDY GUIDE 2026/2027
ACCURATE QUESTIONS WITH CORRECT
DETAILED SOLUTIONS ||
100% GUARANTEED PASS
<NEWEST VERSION>
1. What is the purpose of dynamic dampers on crankshafts? - ANSWER ✔
They reduce engine vibration.
2. What types of bearings are generally found in reciprocating engines? -
ANSWER ✔ Plain, ball and roller bearings.
3. Are the connecting rods used in each cylinder of a radial engine the same?
Explain. - ANSWER ✔ No. Radial engines use master and articulating rod
assemblies.
4. Name the different types of piston rings. - ANSWER ✔ Oil control,
compression, and oil scraper.
5. Where should piston ring gaps be installed relative to each other, and why? -
ANSWER ✔ Compression ring gaps should be staggered so that they do
not align. This prevents excessive blow-by.
6. What could result from incorrectly installed piston rings? - ANSWER ✔
Excessive oil consumption.
7. What purpose do oil control rings serve? - ANSWER ✔ They regulate the
thickness of the oil film on the cylinder walls.
,8. What is done to ensure that each generator shares the load in a multiple
generator system? - ANSWER ✔ The generators are paralleled.
9. Where would you find generator rating and performance data? - ANSWER
✔ On the data plate attached to the generator.
10.How is the voltage of a DC generator controlled? - ANSWER ✔ By
varying the field current strength
11.What is the most common type of alternator used in most aircraft AC
systems? - ANSWER ✔ The three phase alternator.
12.How does the voltage regulator control the voltage of an alternator? -
ANSWER ✔ By regulating the voltage output of the DC exciter.
13.What does the speed of rotation and number of poles of an alternator
determine? - ANSWER ✔ The frequency of the alternator output.
14.What are some of the methods used to maintain 400 Hertz alternator output
frequency on large turbojet or turbofan engines? - ANSWER ✔ Constant
speed drives, integrated drive generators, and variable speed constant
frequency (VSCF) power systems.
15.Name the major parts of a DC motor. - ANSWER ✔ The armature, field,
brushes, and frame assembly.
16.Name the components of a direct cranking electric starter system. -
ANSWER ✔ An electric motor, reduction gears, and an automatic
engaging and disengaging mechanism.
17.Name three types of DC motors. - ANSWER ✔ Series, shunt and
compound.
18.What type of DC motor is commonly used for a reciprocating engine starter
and why? - ANSWER ✔ A series wound motor is commonly used because
it has a high starting torque under heavy load conditions.
,19.What are the operating modes of a turbine engine starter generator? -
ANSWER ✔ It operates first as a starter, then as a generator once the
engine is running.
20.What is a possible indication when a starter drags? - ANSWER ✔ A dirty
or worn starter commutator.
21.Where would wire with high temperature insulation material be used? -
ANSWER ✔ When they run close to high temperature areas such as
exhaust stacks or heating ducts.
22.What is the size standard for electrical wire used in US manufactured
aircraft? - ANSWER ✔ The American Wire Gauge (AWG).
23.How are wire sizes represented? - ANSWER ✔ By a numbered gauge size.
The smaller wires are represented by larger numbers. The smallest size wire
normally used in aircraft is 22-gauge.
24.What is the maximum slack allowed between the supports of a single wire or
bundle installation? - ANSWER ✔ Not over 1/2 inch deflection.
25.Why are wires bonded on powerplant installations? - ANSWER ✔ To
provide a current return path for electrical accessories, and to prevent static
discharge.
26.A reciprocating engine is found to have excessive oil consumption without
evidence of any oil leaks. What is the likely cause? - ANSWER ✔ The
piston rings are worn or broken.
27.What are the functions of lubricating oil in reciprocating engines? -
ANSWER ✔ To reduce friction between moving parts and remove heat.
28.What type of transparent plastic material is used for most aircraft
windshields? - ANSWER ✔ Acrylic plastic.
29.How should sheets of transparent plastic material be stored? - ANSWER ✔
Leave the protective paper on the material and store it tilted approximately
10° from the vertical.
, 30.How tight should the screws be tightened when installing an acrylic
windshield in a channel? - ANSWER ✔ Tighten the screw to a firm fit and
back it off one full turn.
31.What is meant by crazing of transparent plastic material? - ANSWER ✔
Tiny hair-like cracks that may not extend all of the way to the surface.
Crazing is caused by stresses or chemical fumes.
32.What type of material is used to remove surface damage to a piece of acrylic
resin? - ANSWER ✔ Micro-Mesh® abrasive sheets.
33.What are the two fuel gases most generally used for gas welding? -
ANSWER ✔ Oxygen and acetylene.
34.What fuel gases are used for welding aluminum? - ANSWER ✔ Oxygen
and hydrogen.
35.What are two types of torches used in gas welding? - ANSWER ✔
Balanced-pressure torches and injector torches.
36.What color lenses are used for gas welding steel? - ANSWER ✔ Green or
brown.
37.What color lenses are used for gas welding aluminum? - ANSWER ✔
Blue.
38.Why is it important that the pressure of the gas in acetylene cylinder be kept
low? - ANSWER ✔ Acetylene gas becomes unstable when it is kept under
pressure of more than about 15 psi.
39.What determines the amount of heat that is put into a weld by an oxy-
acetylene torch? - ANSWER ✔ The size of the orfice in the torch tip.
40.What is the difference in the appearance of an oxidizing flame, a neutral
flame, and a reducing flame produced by an oxy-acetylene torch? -
ANSWER ✔ An oxidizing flame has a pointed inner cone, and the torch
makes a hissing noise. A neutral flame has a rounded inner cone, and there is
