RECIPROCATING ENGINES RECIPROCATING ENGINES
What are the basic types or configurations of Inline, Opposed, V-Type, and Radial
reciprocating engines?
The piston in cylinder number 1 should be in the correct position for ignition to occur.
In what position should the crankshaft be This is normally about 30 degrees before top center on the compression stroke.
when a magneto is being timed to the
engine?
Idling RPM and manifold pressure, engine acceleration, maximum static RPM and
What is checked on engine runup to manifold pressure, magneto drop, ignition switch safety check, propeller pitch change
determine the operational condition of the propeller feathering, oil pressure, fuel pressure, and fuel flow.
engine?
Oil has drained past the piston rings and filled the combustion chamber of cylinders
that are below the center of the engine. If the crankshaft is turned over with this oil in
What is hydraulic lock in an aircraft engine? the cylinder it will lock, and there is a probability that the piston, cylinder, or connecting
rod will be damaged.
How is a hydraulic lock removed from an Remove a spark plug from the locked cylinder and drain all of the oil out. Clean the
aircraft engine? sprak plug and replace it.
Intake, Compression, Power, and Exhaust
What are the strokes of a 4-stroke
reciprocating engine?
Piston rings not seating or broken, and valves not seating or burned.
What are the two main causes of a cylinder
having low compression?
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
What is a low-tension ignition system? directed through a very short high-tension lead to a spark plug. There is one
transformer for each spark plug.
What are some advantages of a horizontally Low power-to-weight ratio, ideal for installation on aircraft wings, and low vibration
opposed engine? characteristics.
How can you determine the firing order of an Begin with cylinder 1, and add 11 or subtract 7, whichever will keep the numbers
18-cylinder radial engine? between 1 and 18. 1-12-5-16-9-2-13-6-17-10-3-14-7-18-11-4-15-8.
It is a cam ring that rides on a shelf-type bearing with a large amount of clearance
between the bearing and 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
What is aa floating cam ring on a large radial must be removed so the cam ring will be tight against the bearing for the valves being
engine? adjusted.
Most horizontally opposed engines have hydraulic valve lifters that keep all of the
Why is valve clearance adjusted on radial clearance out of the valve train. Radial engines have solid lifters.
engines, but not on most horizontally
opposed engines?
The hot clearance is given for valve timing purposes. The timing is adjusted with the
Why are both the hot and cold valve valves in cylinder number one, set with the hot clearance. When the timing is set, all of
clearances given for most radial engines? the valves are adjusted to their cold clearance.
Moisture will accumulate in the engine, initiating the corrosion process which can ruin
Why is it important to preserve engines that the engine.
will not be operated for an extended period
of time?
30 to 90 days.
Preservation for temporary storage is valid
for engines that will be out of service for how
many days?
, Spray a preservative oil inside the cylinders and replace the spark plugs with desiccant
What should be done to the cylinders to plugs.
protect them from rust and corrosion when
preparing the engine for long-time storage?
Indicated Horsepower = (PLANK)/33,000
Where:
P = Indicated mean effective pressure, in psi
L = Length of stroke, in feet or in fractions of a foot
What is the formula for calculating indicated A = Area of the piston head or cross-sectional area of the cylinder, in square inches
horsepower on a 4-stroke engine? N = Number of power strokes per minute: RPM/2
K = Number of cylinders
SFC is a measure of the economical use of fuel, which is the fuel weight in pounds per
hour per horsepower:
What is specific fuel consumption (SFC)? SFC = (pounds fuel/hour)/horsepower
What must be inspected to determine the The propeller, lubrication system, ignition system, fuel metering system, cooling
airworthiness of an engine installation? system, and the exhaust system.
In the Type Certificate Data Sheets for the aircraft.
Where can you find the correct grade of fuel
and the amount of engine lubricating oil for
an aircraft engine?
a. Know how the system should operate.
b. Observe how the system is operating.
What are the basic steps in troubleshooting c. Divide the system into smaller parts to find the trouble.
an engine installation? d. Look for the obvious problem first.
In the aircraft maintenance manual
Where do you find instructions for removing
an engine from an aircraft?
The tail of the airplane must be supported.
What must normally be done to a nose-
wheel airplane before removing an engine?
The correct plugs or caps. Never cover the end of a line with tape.
What should be used to cover the ends of
fuel and oil lines that have been
disconnected from the engine?
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
What is meant by a QEC engine assembly? engines. All that is needed is for the controls, wiring, and fluid lines to be connected to
the firewall.
The control on the engine component must contact its stop before the control handle in
What is meant by rigging the engine controls the flight deck reaches its stop. This causes the control handle to spring back a slight
so they have some "cushion"? amount when it is moved to the extent of its travel.
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 gage
connects.
What are two ways of pre-oiling an engine? b. Use a pre-oiler tank. Air pressure forces oil through all of the passages until some of
it flows from the oil pressure gage fitting.
Idle RPM and mixture, static RPM, propeller pitch change operation, magneto check,
What checks should be made to determine ignition switch safety check, and carburetor heat check.
the proper operation of a reciprocating
engine installation?
, 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
What is the purpose of a cold cylinder feel the exhaust stack near the cylinder head. The cylinder with the stack that is not as
check? hot as the others is the cylinder that has not been firing.
If the ignition switch is on, or a magneto ground wire is faulty the engine can start if the
impulse coupling is fired when the propeller is turned. Maintenance personnel should
What are the risks of moving a propeller by always verify the magneto switch is off and stay clear of the propeller arc any time the
hand during aircraft maintenance? propeller is moved.
Improper procedures during ground runs can cause damage to the aircraft and injury
What precautions should be taken prior to personnel. The maintenance manual and operational checklists should always be used
and during ground operations of an engine? when operating an engine and aircraft on the ground.
Improper procedures can lead to further damage to the engine and aircraft. If the
engine backfires and causes a fire in the induction system, the starter motor should
continue to run while mixture control is pulled to idle cutoff to prevent more fuel from
entering the engine. If the fire is outside of the engine, pull the mixture control to idle
What are the risks associated with incorrect cutoff and close the fuel firewall shutoff valve to stop the flow of fuel into the engine
procedures in the event of a reciprocating
compartment. After aircraft maintenance, it is good practice to have a spotter standing
engine fire?
by with a fire extinguisher.
The risks of using other procedures is that important steps and procedures can be
What risks are associated with using missed, causing damage to the engine, aircraft, or personnel. The manufacturer's
procedures other than those developed by procedures were carefully developed to maintain the type design configuration and
the manufacturer? safety of the aircraft.
TURBINE ENGINES TURBINE ENGINES
Intake = air inlet section, Compression = compressor section, Ignition and power =
How are the four strokes of a reciprocating combustion and turbine sections, Exhaust = exhaust section.
engine similar to the sections of a turbine
engine?
High-bypass turbofan engines.
What type of turbojet engine is commonly
used in commercial aviation due to lower
noise and better fuel consumption?
What four types of gas turbine engines are Turbofan, turboprop, turboshaft, and turbojet.
used in aircraft?
Centrifugal flow and Axial flow
What are the two types of turbine
compressors?
Adjusting the fuel control so the engine develops the correct idle and trim speed RPM.
What is meant by trimming a turbine engine?
A JetCal analyzer/trimmer has all of the instrumentation and cables to determine the
What type of equipment should be used to EGT, EPR, and other parameters specified by the engine manufacturer.
determine that a turbine engine is
performing up to the standards specified by
the engine manufacturer?
An inspection of the hot section of a turbine engine. The hot section includes the
What is meant by a hot-section inspection? combustors, the turbine, and the exhaust system.
The monitoring of of the engine performance at regular intervals and determining when
What is meant by on-condition maintenance maintenance is required based on certain operating parameters specified by the
of a turbine engine? engine manufacturer.
What are the basic types or configurations of Inline, Opposed, V-Type, and Radial
reciprocating engines?
The piston in cylinder number 1 should be in the correct position for ignition to occur.
In what position should the crankshaft be This is normally about 30 degrees before top center on the compression stroke.
when a magneto is being timed to the
engine?
Idling RPM and manifold pressure, engine acceleration, maximum static RPM and
What is checked on engine runup to manifold pressure, magneto drop, ignition switch safety check, propeller pitch change
determine the operational condition of the propeller feathering, oil pressure, fuel pressure, and fuel flow.
engine?
Oil has drained past the piston rings and filled the combustion chamber of cylinders
that are below the center of the engine. If the crankshaft is turned over with this oil in
What is hydraulic lock in an aircraft engine? the cylinder it will lock, and there is a probability that the piston, cylinder, or connecting
rod will be damaged.
How is a hydraulic lock removed from an Remove a spark plug from the locked cylinder and drain all of the oil out. Clean the
aircraft engine? sprak plug and replace it.
Intake, Compression, Power, and Exhaust
What are the strokes of a 4-stroke
reciprocating engine?
Piston rings not seating or broken, and valves not seating or burned.
What are the two main causes of a cylinder
having low compression?
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
What is a low-tension ignition system? directed through a very short high-tension lead to a spark plug. There is one
transformer for each spark plug.
What are some advantages of a horizontally Low power-to-weight ratio, ideal for installation on aircraft wings, and low vibration
opposed engine? characteristics.
How can you determine the firing order of an Begin with cylinder 1, and add 11 or subtract 7, whichever will keep the numbers
18-cylinder radial engine? between 1 and 18. 1-12-5-16-9-2-13-6-17-10-3-14-7-18-11-4-15-8.
It is a cam ring that rides on a shelf-type bearing with a large amount of clearance
between the bearing and 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
What is aa floating cam ring on a large radial must be removed so the cam ring will be tight against the bearing for the valves being
engine? adjusted.
Most horizontally opposed engines have hydraulic valve lifters that keep all of the
Why is valve clearance adjusted on radial clearance out of the valve train. Radial engines have solid lifters.
engines, but not on most horizontally
opposed engines?
The hot clearance is given for valve timing purposes. The timing is adjusted with the
Why are both the hot and cold valve valves in cylinder number one, set with the hot clearance. When the timing is set, all of
clearances given for most radial engines? the valves are adjusted to their cold clearance.
Moisture will accumulate in the engine, initiating the corrosion process which can ruin
Why is it important to preserve engines that the engine.
will not be operated for an extended period
of time?
30 to 90 days.
Preservation for temporary storage is valid
for engines that will be out of service for how
many days?
, Spray a preservative oil inside the cylinders and replace the spark plugs with desiccant
What should be done to the cylinders to plugs.
protect them from rust and corrosion when
preparing the engine for long-time storage?
Indicated Horsepower = (PLANK)/33,000
Where:
P = Indicated mean effective pressure, in psi
L = Length of stroke, in feet or in fractions of a foot
What is the formula for calculating indicated A = Area of the piston head or cross-sectional area of the cylinder, in square inches
horsepower on a 4-stroke engine? N = Number of power strokes per minute: RPM/2
K = Number of cylinders
SFC is a measure of the economical use of fuel, which is the fuel weight in pounds per
hour per horsepower:
What is specific fuel consumption (SFC)? SFC = (pounds fuel/hour)/horsepower
What must be inspected to determine the The propeller, lubrication system, ignition system, fuel metering system, cooling
airworthiness of an engine installation? system, and the exhaust system.
In the Type Certificate Data Sheets for the aircraft.
Where can you find the correct grade of fuel
and the amount of engine lubricating oil for
an aircraft engine?
a. Know how the system should operate.
b. Observe how the system is operating.
What are the basic steps in troubleshooting c. Divide the system into smaller parts to find the trouble.
an engine installation? d. Look for the obvious problem first.
In the aircraft maintenance manual
Where do you find instructions for removing
an engine from an aircraft?
The tail of the airplane must be supported.
What must normally be done to a nose-
wheel airplane before removing an engine?
The correct plugs or caps. Never cover the end of a line with tape.
What should be used to cover the ends of
fuel and oil lines that have been
disconnected from the engine?
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
What is meant by a QEC engine assembly? engines. All that is needed is for the controls, wiring, and fluid lines to be connected to
the firewall.
The control on the engine component must contact its stop before the control handle in
What is meant by rigging the engine controls the flight deck reaches its stop. This causes the control handle to spring back a slight
so they have some "cushion"? amount when it is moved to the extent of its travel.
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 gage
connects.
What are two ways of pre-oiling an engine? b. Use a pre-oiler tank. Air pressure forces oil through all of the passages until some of
it flows from the oil pressure gage fitting.
Idle RPM and mixture, static RPM, propeller pitch change operation, magneto check,
What checks should be made to determine ignition switch safety check, and carburetor heat check.
the proper operation of a reciprocating
engine installation?
, 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
What is the purpose of a cold cylinder feel the exhaust stack near the cylinder head. The cylinder with the stack that is not as
check? hot as the others is the cylinder that has not been firing.
If the ignition switch is on, or a magneto ground wire is faulty the engine can start if the
impulse coupling is fired when the propeller is turned. Maintenance personnel should
What are the risks of moving a propeller by always verify the magneto switch is off and stay clear of the propeller arc any time the
hand during aircraft maintenance? propeller is moved.
Improper procedures during ground runs can cause damage to the aircraft and injury
What precautions should be taken prior to personnel. The maintenance manual and operational checklists should always be used
and during ground operations of an engine? when operating an engine and aircraft on the ground.
Improper procedures can lead to further damage to the engine and aircraft. If the
engine backfires and causes a fire in the induction system, the starter motor should
continue to run while mixture control is pulled to idle cutoff to prevent more fuel from
entering the engine. If the fire is outside of the engine, pull the mixture control to idle
What are the risks associated with incorrect cutoff and close the fuel firewall shutoff valve to stop the flow of fuel into the engine
procedures in the event of a reciprocating
compartment. After aircraft maintenance, it is good practice to have a spotter standing
engine fire?
by with a fire extinguisher.
The risks of using other procedures is that important steps and procedures can be
What risks are associated with using missed, causing damage to the engine, aircraft, or personnel. The manufacturer's
procedures other than those developed by procedures were carefully developed to maintain the type design configuration and
the manufacturer? safety of the aircraft.
TURBINE ENGINES TURBINE ENGINES
Intake = air inlet section, Compression = compressor section, Ignition and power =
How are the four strokes of a reciprocating combustion and turbine sections, Exhaust = exhaust section.
engine similar to the sections of a turbine
engine?
High-bypass turbofan engines.
What type of turbojet engine is commonly
used in commercial aviation due to lower
noise and better fuel consumption?
What four types of gas turbine engines are Turbofan, turboprop, turboshaft, and turbojet.
used in aircraft?
Centrifugal flow and Axial flow
What are the two types of turbine
compressors?
Adjusting the fuel control so the engine develops the correct idle and trim speed RPM.
What is meant by trimming a turbine engine?
A JetCal analyzer/trimmer has all of the instrumentation and cables to determine the
What type of equipment should be used to EGT, EPR, and other parameters specified by the engine manufacturer.
determine that a turbine engine is
performing up to the standards specified by
the engine manufacturer?
An inspection of the hot section of a turbine engine. The hot section includes the
What is meant by a hot-section inspection? combustors, the turbine, and the exhaust system.
The monitoring of of the engine performance at regular intervals and determining when
What is meant by on-condition maintenance maintenance is required based on certain operating parameters specified by the
of a turbine engine? engine manufacturer.
