A&P Power plant Oral Questions, ASA-
OEG-AMT2 with correct Answers
In what position should the crankshaft be when a magneto is being timed to the engine?
- Answer -The piston and cylinder number one should be in the correct position for
ignition to occur. This is normally about 30° before top center on the compression
stroke.
What is the purpose of a cold cylinder check? - Answer -A cold cylinder check
determines which cylinder is not firing. Run the engine for a few minutes at the speed,
and on the magneto, at which it runs roughest. Shut it down and feel the exhaust stack
near the cylinder head. The cylinder with the stack that is not as hot as the others is the
cylinder that has not been firing
What is checked on engine run out to determine the operational condition of the
engine? - Answer -Idling rpm and manifold pressure, engine acceleration, maximum
static RPM and manifold pressure, magneto drop, ignition switch safety check, propeller
pitch change, propeller feathering, oil pressure, fuel pressure, and fuel flow
How can you determine the firing order of an 18 cylinder radial engine? - Answer -Begin
with cylinder 1, add 11 and subtract 7, whichever will keep the numbers between 1 and
18. 1-12 - 5-16 - 9-2 - 13-6 - 17-10 - 3-14 - 7-18 - 11-4 - 15-8
What are two main causes of a cylinder having low compression? - Answer -Piston
rings not seating or broken, valves not seating or burned.
What is a hydraulic lock in an aircraft engine? - Answer -Oil has drained past the piston
rings and filled the combustion chamber of cylinders that are below the center line of the
engine. If the crankshaft is turned over with this oil in the cylinder it will lock, and there is
a probability that the piston, cylinder, or connecting rod will be damaged.
How is hydraulic lock removed from an aircraft engine? - Answer -Remove a spark plug
from the locked cylinder and drain all of the oil out. Clean the spark plug and replace it.
What is a low tension ignition system? - Answer -It is an ignition system using a
magneto with a brush type distributor and a coil that has no secondary wiring. Low
voltage is directed from the magneto to a transformer mounted on the cylinder head.
,Here the low-voltage is boosted to a high-voltage and is directed through a very short
high tension lead to the spark plug. There is one transformer for each spark plug.
What is a floating cam ring in a large radial engine? - Answer -It is a cam ring that rides
on a shelf type bearing with a large amount of clearance between the bearing in the
ring. When adjusting the valves on an engine with a floating cam ring, the pressure of
the valve springs on the opposite side of the engine must be removed so the cam ring
will be tight against the bearing for the valves to be adjusted.
Why is valve clearance adjusted on radial engines, but not on most horizontally
opposed engines? - Answer -Most horizontally opposed engines have hydraulic valve
lifters that keep all of the clearance out of the valve train. Radial engines have solid
lifters
Why are both the hot and cold valve clearances given for most radial engines? - Answer
-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 must be inspected to determine the airworthiness of an engine installation? -
Answer -The propeller, lubrication system, ignition system, fuel metering system,
cooling system, and the exhaust system.
What check should be made to determine the proper operation of a reciprocating engine
installation? - Answer -Idle RPM and mixture, static RPM, propeller pitch change
operation, magneto check, ignition switch safety check, and carburetor heat check.
Where can you find the correct grade of fuel and amount of engine lubricating oil for an
aircraft engine? - Answer -In the type certificate data sheets for the aircraft.
What are the basic steps and troubleshooting an engine installation? - Answer -A. Know
how the system should operate.
B. Observe how the system is operating.
C. Divide the system to find the trouble.
D. Look for the obvious problems first.
Where do you find the procedures to follow when correcting a defective condition in an
aircraft engine? - Answer -In the engine maintenance manual.
Where do you find instructions for removing an engine from an aircraft? - Answer -In the
aircraft maintenance manual.
What must normally be done to a nosewheel airplane before removing an engine? -
Answer -The tail of the airplane must be supported.
, What should be done to the cylinders to protect them from rust and corrosion when
preparing the engine for long time storage? - Answer -Spray a preservative oil inside the
cylinders and replace the spark plugs with desiccant plugs.
What should be used to cover the ends of fuel and oil lines that have been disconnected
from the engine? - Answer -The correct plugs or caps. Never cover the end of a line
with tape.
What is meant by a QEC engine assembly? - Answer -An engine that has been
prepared for a quick engine change. The engine is on its mount and all of the
accessories are installed. A minimum of time is required to change engines. All that is
needed is for the controls, wiring, and fluid lines to be connected to the firewall.
What is meant by rigging the engine controls so they have some "cushion"? - Answer -
The control on the engine component must contact its stop before the control handle in
the cockpit reaches its stop. This causes the control handle to spring back a slight
amount when it is moved to the extent of its travel.
What are two ways of pre-oiling an engine? - Answer -A. Before the spark plugs are
installed and after the oil tank or sump is filled, turn the engine over with the starter until
oil runs out of the fitting to which the oil pressure gauge connects.
B. Use a pre-oiler tank. Air pressure forces oil through all of the passages until some of
it flows from the oil pressure gauge fitting.
What is meant by a hot section inspection? - Answer -An inspection of the hot section of
a turbine engine. The hot section includes the combustors, the turbine, and the exhaust
system.
What is meant by on condition maintenance of the turbine engine? - Answer -The
monitoring of the engine performance at regular intervals and determining when
maintenance is required based on certain operating parameters specified by the engine
manufacturer.
What checks of a turbine engine are necessary to verify preflight condition? - Answer -•
inspection of the cowling and all air inlet areas and attachment of the engine to the
airframe.
• inspection of the inlet guide veins in the first stage of the compressor or fan blades.
• check for unusual noise when the compressor is rotated.
• inspection of the rear turbine, and exhaust system.
• check the quantity of the lubricating oil for the engine and the constant speed drive
unit.
• check the ignition system for operation by listening for the sparks.
What is meant by trimming a turbine engine? - Answer -Adjusting the fuel control so the
engine develops the correct idle and trim speed RPM.
OEG-AMT2 with correct Answers
In what position should the crankshaft be when a magneto is being timed to the engine?
- Answer -The piston and cylinder number one should be in the correct position for
ignition to occur. This is normally about 30° before top center on the compression
stroke.
What is the purpose of a cold cylinder check? - Answer -A cold cylinder check
determines which cylinder is not firing. Run the engine for a few minutes at the speed,
and on the magneto, at which it runs roughest. Shut it down and feel the exhaust stack
near the cylinder head. The cylinder with the stack that is not as hot as the others is the
cylinder that has not been firing
What is checked on engine run out to determine the operational condition of the
engine? - Answer -Idling rpm and manifold pressure, engine acceleration, maximum
static RPM and manifold pressure, magneto drop, ignition switch safety check, propeller
pitch change, propeller feathering, oil pressure, fuel pressure, and fuel flow
How can you determine the firing order of an 18 cylinder radial engine? - Answer -Begin
with cylinder 1, add 11 and subtract 7, whichever will keep the numbers between 1 and
18. 1-12 - 5-16 - 9-2 - 13-6 - 17-10 - 3-14 - 7-18 - 11-4 - 15-8
What are two main causes of a cylinder having low compression? - Answer -Piston
rings not seating or broken, valves not seating or burned.
What is a hydraulic lock in an aircraft engine? - Answer -Oil has drained past the piston
rings and filled the combustion chamber of cylinders that are below the center line of the
engine. If the crankshaft is turned over with this oil in the cylinder it will lock, and there is
a probability that the piston, cylinder, or connecting rod will be damaged.
How is hydraulic lock removed from an aircraft engine? - Answer -Remove a spark plug
from the locked cylinder and drain all of the oil out. Clean the spark plug and replace it.
What is a low tension ignition system? - Answer -It is an ignition system using a
magneto with a brush type distributor and a coil that has no secondary wiring. Low
voltage is directed from the magneto to a transformer mounted on the cylinder head.
,Here the low-voltage is boosted to a high-voltage and is directed through a very short
high tension lead to the spark plug. There is one transformer for each spark plug.
What is a floating cam ring in a large radial engine? - Answer -It is a cam ring that rides
on a shelf type bearing with a large amount of clearance between the bearing in the
ring. When adjusting the valves on an engine with a floating cam ring, the pressure of
the valve springs on the opposite side of the engine must be removed so the cam ring
will be tight against the bearing for the valves to be adjusted.
Why is valve clearance adjusted on radial engines, but not on most horizontally
opposed engines? - Answer -Most horizontally opposed engines have hydraulic valve
lifters that keep all of the clearance out of the valve train. Radial engines have solid
lifters
Why are both the hot and cold valve clearances given for most radial engines? - Answer
-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 must be inspected to determine the airworthiness of an engine installation? -
Answer -The propeller, lubrication system, ignition system, fuel metering system,
cooling system, and the exhaust system.
What check should be made to determine the proper operation of a reciprocating engine
installation? - Answer -Idle RPM and mixture, static RPM, propeller pitch change
operation, magneto check, ignition switch safety check, and carburetor heat check.
Where can you find the correct grade of fuel and amount of engine lubricating oil for an
aircraft engine? - Answer -In the type certificate data sheets for the aircraft.
What are the basic steps and troubleshooting an engine installation? - Answer -A. Know
how the system should operate.
B. Observe how the system is operating.
C. Divide the system to find the trouble.
D. Look for the obvious problems first.
Where do you find the procedures to follow when correcting a defective condition in an
aircraft engine? - Answer -In the engine maintenance manual.
Where do you find instructions for removing an engine from an aircraft? - Answer -In the
aircraft maintenance manual.
What must normally be done to a nosewheel airplane before removing an engine? -
Answer -The tail of the airplane must be supported.
, What should be done to the cylinders to protect them from rust and corrosion when
preparing the engine for long time storage? - Answer -Spray a preservative oil inside the
cylinders and replace the spark plugs with desiccant plugs.
What should be used to cover the ends of fuel and oil lines that have been disconnected
from the engine? - Answer -The correct plugs or caps. Never cover the end of a line
with tape.
What is meant by a QEC engine assembly? - Answer -An engine that has been
prepared for a quick engine change. The engine is on its mount and all of the
accessories are installed. A minimum of time is required to change engines. All that is
needed is for the controls, wiring, and fluid lines to be connected to the firewall.
What is meant by rigging the engine controls so they have some "cushion"? - Answer -
The control on the engine component must contact its stop before the control handle in
the cockpit reaches its stop. This causes the control handle to spring back a slight
amount when it is moved to the extent of its travel.
What are two ways of pre-oiling an engine? - Answer -A. Before the spark plugs are
installed and after the oil tank or sump is filled, turn the engine over with the starter until
oil runs out of the fitting to which the oil pressure gauge connects.
B. Use a pre-oiler tank. Air pressure forces oil through all of the passages until some of
it flows from the oil pressure gauge fitting.
What is meant by a hot section inspection? - Answer -An inspection of the hot section of
a turbine engine. The hot section includes the combustors, the turbine, and the exhaust
system.
What is meant by on condition maintenance of the turbine engine? - Answer -The
monitoring of the engine performance at regular intervals and determining when
maintenance is required based on certain operating parameters specified by the engine
manufacturer.
What checks of a turbine engine are necessary to verify preflight condition? - Answer -•
inspection of the cowling and all air inlet areas and attachment of the engine to the
airframe.
• inspection of the inlet guide veins in the first stage of the compressor or fan blades.
• check for unusual noise when the compressor is rotated.
• inspection of the rear turbine, and exhaust system.
• check the quantity of the lubricating oil for the engine and the constant speed drive
unit.
• check the ignition system for operation by listening for the sparks.
What is meant by trimming a turbine engine? - Answer -Adjusting the fuel control so the
engine develops the correct idle and trim speed RPM.
