What are the two major differences between the three types of jet fuels?

Specific gravity and flash points.

Why do jet fuels tend to ice up at higher altitudes?

Because of the extremely low temperatures and the higher viscosity of jet fuels, which prevent adequate settling of water droplets at low temperatures.

What did the development of the automatic MFC do for jet engine operators?

Relieve them of all direct control over engine acceleration and deceleration rate.

How does the fuel control reduce the possibility of a flameout?

By allowing the engine to accelerate and decelerate at a safe rate.

What are the two purposes for the fuel/oil cooler?

Cool the oil and heat the fuel, which aids vaporization and combustion

How are the thrust and RPM output controlled in many centrifugal and single-spool axial-flow engines?

TIT is allowed to vary inversely with CIT.

What are the two types of fuel controls that are used on most modern aircraft?

Hydromechanical and electrohydromechanical.

Name the four units that make up the unified control system.

Unified control, augmenter pump controller, rear compressor (N2) sensor, and fan exit temperature sensor

Describe the closed loop design of fuel control systems.

The engine sends signals to the fuel control and the electronic control so the fuel control and the EEC know how the engine responded to what the fuel control did.

If you determine that an unauthorized adjustment has been made to a fuel system part, what should you do?

Send the part to the authorized depot.

From what four basic sources does the F100 engine DEEC receive signals?

Engine, MFC, AFC, and airframe.

What drives the impeller on the F100 engine AFP?

13th stage air acting on the turbine.

When classified as to structure, what three types of pumps are used most often in jet engine oil systems? Which of these three is the most common?

Gear, gerotor, and sliding vane, with the gear-type being the most common.

How do air/oil coolers cool the oil?

By passing hot engine oil through the core of the cooler and having ram air pass over the core.

How do fuel/oil coolers cool the oil?

By having fuel flowing into the tubes of the cooler and oil flowing around the fuel-filled cooler tubes.

What are the two types of oil nozzles?

Restrictive tube and internal passage.

Name three general types of oil seals used in jet engines

Synthetic, labyrinth, and carbon.

Why should you use extreme care when working with labyrinth seals?

They are made of soft metal and could be damaged easily.

What is the common method of preloading a carbon seal?

Using spring pressure to push the stationary carbon rubbing surface against the rotating seal plate surface.

What is the purpose of the bypass valve located in the filter assembly?

To permit oil to bypass the coolers on cold weather starts.

Which component directs oil through the augmentor section of the fuel/oil cooler?

The augmenter fuel-flow control valve.

What’s the difference between a hot tank system and a cold tank system?

These terms basically refer to where and at what point the oil is cooled. In a hot tank design, the oil cooler is placed in the pressure subsystem. The cold tank design places the oil cooler in the scavenge subsystem

What indicates a need for maintenance on the F100 engine oil filter?

Pop-out button device (delta P indicator).

What two variables cause the F100 engine oil pressure to vary?

Rear compressor rotor speed (N2) and engine oil temperature.

How is the no. 2 and 3 bearing compartment vented to the gearbox?

Through the gearbox tower shaft cavity.

How does AFTLA receive a sample of each new batch of MIL-PRF–7808 oil?

Automatically from the manufacturer.

What happens to batches of oil not meeting AFTLA requirements?

They are not released for use by the Air Force.

How are users notified if a quality problem arises with a particular oil product?

The Air Force Petroleum Office’s Weapon System Support Branch will send messages via the Defense Messaging System to the MAJCOMs. MAJCOMs will then notify all users of the unsatisfactory product and have it removed from service.

Why should jet engine oil be washed from a person’s skin as soon as possible?

Jet engine oil can contain additives and/or properties that are harmful, including causing skin rashes.

What effect does synthetic oil have on paint, rubber, and some synthetic seals?

Its corrosive properties tend to soften or dissolve them.

Name the three major benefits of the OAP.

Improved safety, reduced maintenance costs, and increased equipment availability.

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Volume 3

CDCs 2a651s

Question	Answer
What are the two major differences between the three types of jet fuels?	Specific gravity and flash points.
Do jet fuels have higher or lower viscosity than aviation gasoline?	Higher.
Why do jet fuels tend to ice up at higher altitudes?	Because of the extremely low temperatures and the higher viscosity of jet fuels, which prevent adequate settling of water droplets at low temperatures.
What did the development of the automatic MFC do for jet engine operators?	Relieve them of all direct control over engine acceleration and deceleration rate.
How does the fuel control reduce the possibility of a flameout?	By allowing the engine to accelerate and decelerate at a safe rate.
What are the two purposes for the fuel/oil cooler?	Cool the oil and heat the fuel, which aids vaporization and combustion
How are the thrust and RPM output controlled in many centrifugal and single-spool axial-flow engines?	TIT is allowed to vary inversely with CIT.
On a dual-spool axial-flow compressor engine, how does the fuel control determine the thrust output of the engine?	By controlling the TIT.
What are the two types of fuel controls that are used on most modern aircraft?	Hydromechanical and electrohydromechanical.
Name the four units that make up the unified control system.	Unified control, augmenter pump controller, rear compressor (N2) sensor, and fan exit temperature sensor
Describe the closed loop design of fuel control systems.	The engine sends signals to the fuel control and the electronic control so the fuel control and the EEC know how the engine responded to what the fuel control did.
If you determine that an unauthorized adjustment has been made to a fuel system part, what should you do?	Send the part to the authorized depot.
What controls engine operation in the primary mode? Secondary mode?	DEEC. MFC.
From what four basic sources does the F100 engine DEEC receive signals?	Engine, MFC, AFC, and airframe.
In what two modes is the F100 engine MFC capable of operating?	Primary or secondary.
If the fuel filter should become clogged on the F100 engine, what component will allow fuel to bypass the filter?	Pressure relief valve.
What drives the impeller on the F100 engine AFP?	13th stage air acting on the turbine.
What component regulates F100 engine AFP speed and fuel flow?	AFPC
What F100 engine component controls the AFC?	DEEC
(401) What is the composition of JP–8 fuel?
(401) At room temperature, how many times longer will it take water to settle out of JP–8 than out of gasoline?
(401) Jet aircraft operating at moderately high altitudes increase the fuel system’s susceptibility to an icing condition, further aggravated by the
(402) The main fuel control allows the jet engine to safely accelerate, reducing the possibility of
(402) During a visual inspection, how can you tell when a fuel filter is clogged?
(403) On a dual-spool, axial-flow engine, what controls thrust production of the engine?
(403) During jet engine deceleration, a hydromechanical fuel control schedules fuel flow as a function of
(403) What type of fuel control uses items such as thermocouples, relays, amplifiers, and solenoids to help control a jet engine?
(403) Which term describes a jet engine fuel metering device that is really two fuel controls in one component?
(403) The F100 UFC senses certain variables from the engine through the use of
(403) If the safety seals on a fuel system component are broken or removed, and you suspect the factory adjustment was altered, you should
(403) Calibration and/or adjustment screws that require setting during an engine trim procedure must be
(404) When in the primary mode, what controls the operation of the F100-PW–220 engine?
(404) On an F100-PW–220 engine, the DEEC is cooled by
(404) For actuation of the variable vane systems on an F100-PW–220 engine, the MFC provides both the CIVV and
(404) Which F100-PW–220 engine fuel system component controls pressurization of the core engine fuel system?
(404) Which stage of compressor air drives the augmenter fuel pump on an F100-PW–220 engine?
(404) On the F100-PW–220 engine, which component controls the augmentor fuel control?
(404) Core engine fuel flow sequence on an F100-PW–220 engine starts at the main fuel pump and then goes through the
What is the most common type of oil tank used in late-model jet engines?	The saddle (form-fitted).
When classified as to function, what two basic types of pumps are used in a jet engine oil system?	Pressure and scavenge.
When classified as to structure, what three types of pumps are used most often in jet engine oil systems? Which of these three is the most common?	Gear, gerotor, and sliding vane, with the gear-type being the most common.

What is the purpose of oil coolers that are installed in oil systems?	To reduce oil temperature.
How do air/oil coolers cool the oil?	By passing hot engine oil through the core of the cooler and having ram air pass over the core.
How do fuel/oil coolers cool the oil?	By having fuel flowing into the tubes of the cooler and oil flowing around the fuel-filled cooler tubes.
What two methods are used for controlling oil cooler bypass valves?	Thermostats and springs.
What are the two types of oil nozzles?	Restrictive tube and internal passage.
What is the purpose of oil system seals?	To prevent the loss of fluid.
Name three general types of oil seals used in jet engines	Synthetic, labyrinth, and carbon.
What two items should you check on new replacement synthetic seals?	The cure date and part number.
Why should you use extreme care when working with labyrinth seals?	They are made of soft metal and could be damaged easily.
What is the common method of preloading a carbon seal?	Using spring pressure to push the stationary carbon rubbing surface against the rotating seal plate surface.
How does oil get from the oil tank to the main pressure stage of the oil pump assembly?	It is gravity fed.
What is the purpose of the bypass valve located in the filter assembly?	To permit oil to bypass the coolers on cold weather starts.
Which component directs oil through the augmentor section of the fuel/oil cooler?	The augmenter fuel-flow control valve.
What type of sump system is sometimes used on a small gas turbine engine?	Wet sump.
What’s the difference between a hot tank system and a cold tank system?	These terms basically refer to where and at what point the oil is cooled. In a hot tank design, the oil cooler is placed in the pressure subsystem. The cold tank design places the oil cooler in the scavenge subsystem
What indicates a need for maintenance on the F100 engine oil filter?	Pop-out button device (delta P indicator).
How many air/oil coolers are provided on the F100–220 for heat absorption of hot engine oil?	Two.
What two variables cause the F100 engine oil pressure to vary?	Rear compressor rotor speed (N2) and engine oil temperature.
How is the no. 2 and 3 bearing compartment vented to the gearbox?	Through the gearbox tower shaft cavity.
How does AFTLA receive a sample of each new batch of MIL-PRF–7808 oil?	Automatically from the manufacturer.
What happens to batches of oil not meeting AFTLA requirements?	They are not released for use by the Air Force.
How are users notified if a quality problem arises with a particular oil product?	The Air Force Petroleum Office’s Weapon System Support Branch will send messages via the Defense Messaging System to the MAJCOMs. MAJCOMs will then notify all users of the unsatisfactory product and have it removed from service.
Why should jet engine oil be washed from a person’s skin as soon as possible?	Jet engine oil can contain additives and/or properties that are harmful, including causing skin rashes.
What effect does synthetic oil have on paint, rubber, and some synthetic seals?	Its corrosive properties tend to soften or dissolve them.
What should you do with lubricating oil in excess of what is needed for immediate servicing?	Dispose of it.
Name the three major benefits of the OAP.	Improved safety, reduced maintenance costs, and increased equipment availability.
Who is responsible for serving as the contact point between maintenance and the OAP laboratory?	OAP project monitor.
What form must accompany all oil samples sent to OAP testing facilities?	DD Form 2026.
Where will you find wear metal guidelines for your particular engine?	In the 33-1-37 series TOs.
Define wear metals.	Small particles of metal worn off contacting surfaces by friction. They can be microscopic in size and suspended in the lubricating fluids.
What is the rate of production of wear metals under normal conditions?	Constant and quite low.
What could be the result of improperly taking an oil sample?	Unsatisfactory system evaluation and possible loss of aircraft.
What type of oil sample would the OAP laboratory ask for if the first sample showed an abnormal wear trend?	An immediate check (red tagged) sample.
Name the two places on the engine that are used for taking oil samples.	Oil tank filler neck and oil tank drain.
On what two factors does the integrity of an oil sample depend?	Whether the oil has circulated in the system long enough to accumulate wear metal concentrations that will indicate the condition of the system, and whether the oil sample truly represents the oil circulating in the system.
At what two times should you not take oil samples?	Less than five hours after an oil change and immediately after oil has been added.
What is an advantage of shorter oil sampling intervals?	The greater probability that initial evidence of failures will be detected.
An aircraft is on a 25-hour oil sample schedule. It’s scheduled to fly a six-hour mission tomorrow. The last sample was taken at 9,232 aircraft hours and the aircraft now has 9,254 hours. When should the sample be taken?	Either before or as soon as possible after engine/equipment shutdown after flight and before any fluid is added. Both times would fall within the ±10 percent of required sampling schedule.
How does an organization normally receive notification that an oil sample reflects a discrepancy?	By telephone.
Generally, when should special oil samples be taken?	Whenever you suspect something is wrong with an oil system, or as directed by the TO when some abnormal condition exists within the engine.
Why should great care be taken during sampling to avoid contact between the sampling tube and any other surfaces?	To prevent contamination.
What is SEM/EDX and what equipment is it comprised of?	An Engine Health monitoring tool developed for automated chemical and structural microanalysis of multiple debris particles; consists of a laboratory standard Scanning Electron Microscope fully integrated with X-ray and image analysis software.
What is SEM/EDX used for?	To identify and monitor material characteristics that can give an indication of accelerated wear or impending failure of typical oil wetted parts and components.
What is the major difference between SEM/EDX and the oil analysis process?	The debris particles being analyzed must be free of oil.
What kind of information do the results of the JetSCAN provide?	Number of particles in each material class, size of each particle, composition of each particle, calculated risk and recommended actions.
(405) When classified as to structure, which of the following is not a type of an oil pump?
(405) Which type of oil pump consists of a gear and rotor within a housing?
(405) One micron is a metric linear measurement that is equal to
(405) Chip detectors have an electrical connection for making which type of check?
(405) Which type of valve permits oil flow in only one direction?
(405) Which type of oil cooler operates on the same principle as a radiator in an automobile?
(405) The purpose of an oil-temperature control valve used with air/oil coolers is to
(405) What type of oil seal has soft metal as its basic composition and allows a small amount of airflow to prevent oil seepage?
(405) Use extreme care when working with labyrinth seals because of their
(405) When an engine is not operating, static preload for a carbon oil seal is provided by
(405) Carbon seals should be cleaned by soaking them in clean, warm
(406) The F100-PW–100 engine oil pressure varies with N2, engine inlet oil temperature, and
(406) What term is used to indicate that air is being mixed with the oil in the oil pump to create pockets of air?
(406) The number1, 4, and 5 bearing compartments are capped on the F100-PW–100 engine oil system. Which oil subsystem (or subsystems) do these compartments breathe through?
(406) Which type of oil system stores the oil in a tank fitted to the side of the engine?
(406) Which type of oil system design places the oil cooler in the pressure subsystem?
(406) Which type of oil tank design do most fighter aircraft engines incorporate to help with weight savings?
(407) On an F100 engine, the breather pressurizing valve is internally mounted in the
(407) If the red button on an F100-PW–220 engine oil filter pops out and remains extended, the
(407) On an F100-PW–220 engine, the air/oil coolers are mounted on the fan duct and use
(407) On an F100-PW–220 engine, what component permits oil to bypass the oil filter during cold weather starts?
(407) On an F100-PW–220 engine, which bearing compartments drain into the gearbox by the tower shaft cavity?
(408) How does the AFTLA obtain oil samples for analysis?
(408) The hazardous property of modern jet engine oil the journeyman must be aware of is
(408) Which action concerning open oil containers is correct?
(409) Through the use of spectrometric oil analysis, aircraft will have a higher in-commission rate because there will be
(409) For bases that do not have an OAP laboratory, who designates the facility to which oil samples are sent?
(409) Who is responsible for ensuring that the OAP operates properly?
(409) What are microscopic metallic particles in the oil system called?
(409) Increased friction between moving parts in the oil system
(409) During an OAP sample collection, using your mouth to draw oil up into the plastic tube could result in
(409) Before taking an oil sample from a drain, drain enough fluid into a container in order to
(409) Oil sampling intervals should not vary by more than
(409) The SEM/EDX analysis process differs from conventional oil analysis in that the SEM/EDX
How is voltage produced?	By electrical phenomenon induction. For example: moving a conductor through a stationary magnetic field, or by varying the strength of a magnetic field that links a conductor.
What is the basic difference between DC and AC?	Direct current is the flow of current in one direction; alternating current reverses its direction at regular intervals.
What device can be used to temporarily store electricity?	A capacitor.
In what position is the rotating loop in a generator when no voltage is being produced?	Vertical
How is AC developed within a generator changed to DC? PAGE 3-38 #5 VOL 3	Each half of a commutator is connected to one terminal of the loop in the generator. Two brushes ride against the commutator segments and carry the current produced by the generated voltage to the external circuit. These brushes are set so each half of th
What is the purpose of the CSD?	To drive the AC generator at a constant speed regardless of engine RPM.
List the two functions of the CSD governor system.	To control the drive output speed and thereby, the generator frequency; and equalize the load between generators operating in parallel.
What unit senses variations from the desired CSD output speed?	The basic speed governor.
What method does the CSD use to adjust the basic speed governor? Explain.	By magnetic force. A trim coil that is mounted directly above the flyweights receives the signals from the frequency-and-load controller. This coil then uses magnetic force to add to or subtract from the centrifugal force of the governor flyweights.
Why is there a “necked-down” section on the CSD drive shaft spline?	To protect the engine from damage in the event of major failure of the CSD, drive shaft, or adapter.
What is the purpose of the CSD drive shaft?	To transmit power from the engine to drive the CSD.
What unit makes up for differences in the alignment of the CSD and engine adapter?	The CSD driveshaft.
What does the suffix N of wire D–2822N, which leaves the master warning box, mean?	It is a ground wire.
If the pneumatic pressure switch were placed in the NO position, how would current flow be affected?	It would stop.
When the thermocouples in an EGT system are hooked up in parallel, what type of circuit is this?	Averaging.
What is the purpose of the resistor in the EGT system?	To calibrate the EGT indicator in the flight station.
You receive a work order with the following information: The pilot reports radio interference during engine starting. Which component in the ignition unit is most likely malfunctioning?	The radio filter.
What three places does the AC generator send power?	The electrical current is distributed to the high main and augmenter ignition systems and the DEC.
Where is the T2 sensor mounted?	The sensor is mounted on the front frame at approximately 5:00 as viewed from the front of the engine with a sensor element projecting into the air stream between IGVs.
Where does the fan speed send its signal?	The fan speed sensor generates an electrical signal, proportional to fan speed, which is transmitted to the DEC.
What component consists of one alumel and one chromel wire welded together?	T5.6 thermocouple consists of one chromel wire and one alumel wire welded together
Approximately how many volts does the AC ignition system deliver to the igniter plugs?	20,000 VAC.
What are the three main parts of an AC ignition system?	Ignition relay, transformer, and igniter plug.
What are the three main parts of a DC ignition system?	Vibrator, transformer, and igniter plug
What function does the vibrator unit in the DC ignition system perform?	It changes direct current to pulsating current.
Where does the exciter get its power on an F100 engine?	From the engine generator
What is the discharge rate for the main (core) igniter plug on a F100 engine?	One to five sparks per second.
What is the basic requirement for a jet engine starter to be effective?	It must be able to rotate the engine compressor to a predetermined speed, enabling the engine to accelerate even after the starter is disengaged.
Name the two types of jet engine starters discussed in this lesson.	Air turbine (impingement), pneumatic, and cartridge-pneumatic.
Match the type of starter in column B with its description in column A. Column B entries may be used more than once. DELETE
Where does the JFS receive its fuel supply?	From the aircraft.
List three advantages of a JFS.	Quick engine starts, the capability for motoring or starting the engine without the use of any ground support equipment, and the capability for starting the engine while in flight at altitudes of up to approximately 20,000 feet.
What type of combustion section does the JFS have?	Reverse flow, annular type.
The compressor inlet gearbox housing of the JFS provides drive pads and mounting flange for what assemblies?	Fuel control, two-speed switch assembly, and CGB.
What is the main purpose of the JFS power turbine assembly?	To provide energy for driving the JFS/CGB/AMAD system gearboxes, engine starting, and aircraft accessories.
What four items comprise the JFS fuel system?	Fuel-flow bypass, fuel filter assembly, fuel control assembly, and fuel atomizer and tubes assemblies.
What system maintains positive pressure within the fuel control during periods of shutdown?	Bypass flow system.
What drives the JFS fuel control?	The gas generator.
What is the purpose of the JFS fuel control?	To control the amount of fuel flowing into the combustion chamber.
What component does the JFS system depend upon for its oil lubrication?	CGB.
Name the three items that comprise the JFS ignition system.	Ignition unit, igniter plug, and a high-voltage ignition lead.
The JFS drain system consists of what two items?	Combustion chamber drain valve and fuel drain support assembly.
Name the four major assemblies that make up the F-15 SPS.	JFS, CGB, left AMAD gearbox, and right AMAD gearbox.
How are the JFS and CGB connected?	By a V-band clamp.
If the JFS power turbine should accelerate to a 110 percent overspeed condition, what item would provide a safety cutoff?	Power turbine overspeed switch.
Name the four basic constructional features of an AMAD.	Housing assembly, geartrain, lubrication system, and a 50-percent engine cutout switch assembly.
What constructional feature is part of LH AMAD only?	The manual decoupler.
What is the purpose of the 50-percent engine cutout switch assembly?	To stop the engine starting cycle when the engine has accelerated to starter cutout speed.
After the JFS has reached self-sustaining speed, how is the hydraulic start motor disengaged?	By an overrunning clutch
At what point during the start sequence is the JFS ready for engine starting?	After the JFS stabilizes at idle.
What must be done to shut down the JFS after the second engine has been started?	Nothing, the JFS shuts down automatically after the engine arrives at starter cutout speed.
(410) What is the term for the process of producing voltage in a conductor when it passes through a magnetic field?
(410) The difference between DC and AC is that DC
(410) On a simple AC generator, which item takes the current from the slip rings to operate the electrical device?
(410) Which part of a generator acts as an automatic switching device, changing alternating current to direct current?
(411) One function of the CSD governor system is to
(411) Which component ensures the CSD output speed is always at the desired RPM to adjust and maintain the desired 400 Hz?
(411) What provides the PTO shaft that is used to drive the CSD?
(412) How are the thermocouples connected in an averaging type of EGT circuit?
(412) The slide-type resistor in the EGT circuit is used to
(412) What is the primary input power to the main ignition system?
(413) How many sets of imbedded magnets does the rotor contain?
(413) What does the EGT/T5.6 thermocouple consist of?
(414) Which unit of an AC ignition system develops 20,000 volts?
(414) A simple DC ignition system consists of vibrator,
(415) How many independent circuits are within an F100-PW–100 engine ignition system?
(415) An F100-PW–100 engine augmentor igniter plug ionizes at a minimum rate of how many sparks per second?
(416) Which statement best describes the air turbine (impingement) starter?
(416) The two air source requirements for a pneumatic starter to operate properly are sufficient
(417) The JFS is basically a
(417) Which item initially rotates the JFS?
(417) Which type of combustion chamber does the JFS use?
(417) What engine section houses the JFS combustion section?
(417) Which item on the JFS provides pads for mounting the fuel atomizer assembly?
(418) The F-15 secondary power system does not include the
(418) Which component provides an electrical safety cutoff for the JFS if the power turbine accelerates to a 110 percent overspeed condition?
(418) On the F-15 secondary power system CGB, how are the isolation decouplers extended?
(418) Oil is supplied to the F-15 JFS through the
(418) On an F-15, the power to start the engines begins with the JFS and continues through the CGB to the
(418) On the F-15 secondary power system, what is used to stop the JFS starting cycle when the aircraft engine has accelerated to starter cutout speed?
The engine anti-icing system is designed to prevent ice formation by using what as a heat source?	Engine compressor discharge air.
What are the effects of ice buildup on an engine inlet?	Loss of thrust that is detected on certain axial-flow engines by a drop in turbine discharge pressure or engine pressure ratio if the condition is sufficiently severe.
What is usually the first indication of ice formation at the engine inlet?	A compressor stall.
Why is the anti-ice valve held open during engine start?	To help bleed the compressor in order to help prevent a compressor stall.
Compressor bleed air is extracted from what stator exit stage?	The 5th stage.
Air is ducted into the fan flow path through how many exit slots?	13.
What two methods are used to control airflow through an engine compressor?	Restricting the airflow by the use of VSVs or dumping off excess air at the appropriate time through a bleed valve or bleed strap arrangement.
Where are variable vanes usually positioned in a compressor to control airflow most effectively?	In the first few stages of compression.
Briefly explain the difference between the bleed system and the variable vane system.	VSVs control air before it gets into the compressor; the bleed system lets all the air in, but bleeds off a certain amount of air at a particular stage of compression.
Where is a bleed strap located on an engine? How is it controlled?	Wrapped around the compressor case. It is controlled by some type of actuator.
What is considered a critical range of operation for dual-rotor compressor engines?	That point where the low-speed N1 air supply is more than the high-speed N2 can use.
Why is air bled from the N1 compressor?	To prevent stalls through the critical ranges of engine operation.
What is the potential outcome if airflow is not properly controlled during engine operation?	Compressor stall.
List the six conditions that could cause a compressor stall.	Reduction or restriction of the air inlet Excessive fuel scheduling Restriction of the turbine noz discharge area. Restriction of the exhaust noz area Damaged or dirty compressor rotor blades Malfunction of the variable geometry sys or bleed air sys
From which stages of compressor airflow do the turbine nozzle vanes receive cooling airflow to help them survive the heated environment?	The last few stages.
What two types of stress act on the turbine rotor blades?	Heat and rotational forces.
Where does cooling airflow go after it has cooled the turbine section?	Back into the gas stream to exit the engine along with the exhaust gases.
What part of the IGV is fixed and serves as an integral part of the front frame?	Forward position.
The fan IGV flap position is scheduled by what component?	Digital electronic control.
What is the position of VSVs when the corrected core engine speed is below 45 percent?	Fully closed (cambered).
What components provide the required force to move the VSVs?	Core compressor VSV actuators.
What two variables determine the position of the 3-D cam?	Core engine speed and fan discharge temperature signals
(419) Discharge air used for aircraft engine anti-icing to heat-critical areas is taken from which engine area?
(419) What is one of the first indications of ice formation at aircraft engine inlets?
(420) On an F110-GE–129 engine, the anti-icing system prevents detrimental formation and accumulation of ice on front frame struts, forward centerbody, and
(420) On an F110-GE–129 engine, compressor bleed air is used for anti-icing, customer bleed, and
(421) What law does the C-D supersonic inlet use to slow down the airflow?
(421) The bleed air system is different from the variable vane system in that it
(421) The compressor bleed system reduces the probability of compressor stall in a dual-rotor engine by
(422) The cooling air for turbine nozzle vanes comes from
(422) Once the cooling airflow has done its job of cooling the turbine section, where does it go?
(423) The F110-GE–129 engine controls airflow through the engine with the
(423) Below what percentage of core engine speed are the VSV fully closed (cambered) on an F110-GE–129 engine?
(423) On an F110-GE–129 engine, the MEC schedules the variable vane positions by the
(423) What is the function of the flexible feedback cable on the F110-GE–129 engine variable vane system?
How is the oil pressure displayed?	The oil pressure indicator system displays the amount of oil pressure in psi.
What type of information does the EDU store?	Historical information, engine events and abnormalities, and diagnostic/faults isolation data.
What two signals does the OPT receive?	Breather (air) and direct oil pressure (fluid).
What powers the EDU?	Aircraft electrical system
How is N2 speed displayed?	Indicator displays the percent of maximum-rated RPM of the rear compressor (core) not actual RPM.
What does the ENPT do?	Transmits an electrical signal to the nozzle position indicator in the cockpit
What is the unit of measure for FTIT?	Degrees centigrade.
Where is FTIT measured from?	Behind the high pressure turbines.
How is fuel flow measured?	pph
Where does the EMSC receive aircraft data from?	DEC.
The EMSC performs diagnostics to fault isolate what?	LRUs.
What is the purpose of the FADEC in the engine monitoring system?	They provide engine fault events/fault detection, fault isolation and fault accommodation for the engine. Additionally, they provide fault and engine data to the CEDU and air vehicle processors.
Where does the CEDU receive its primary power?	The engine-driven generator and backup power from the airframe.
Name the four fundamental parts of an augmentor.	(1) Augmentor duct. (2) Spraybars. (3) Flameholder. (4) Exhaust nozzle.
What does the augmentor duct contain? What does it support?	The augmentor combustion chamber liner; the augmentor nozzle and actuators.
Which part of the augmentor reduces the velocity of the gases so that the flame stability is maintained during augmentor operation?	The flameholder.
What is the primary purpose of a typical variable-nozzle system?	To provide the correct nozzle area for proper engine operation in both augmentor and nonaugmentor operation.
Name the four types of variable-nozzle systems.	(1) Flap. (2) Iris. (3) Convergent-divergent. (4) Vectoring.
What is used to operate the flaps in the flap-type nozzle system?	Air pressure acting on a series of pistons.
How many positions does a typical iris-type nozzle system have?	Two
What is the most important advantage gained from using a C-D variable-nozzle system?	Increased life expectancy of the engine and augmentor due to the system’s positive temperature control.
What is the purpose of augmentor ignition systems?	To develop the spark necessary to ignite the fuel in the augmentor
What are the two methods of igniting the augmentor fuel?	Torch igniter and pilot burner ring.
How does the torch igniter initiate afterburning?	A small combustion chamber shell, extending into the augmentor duct, is used to ignite the fuel with the fuel, air, and an electric spark supplied to the torch igniter.
What causes ignition on the pilot burner ring system?	Combination of atomized fuel and the sparking igniter plug.
What types of materials are used to construct the augmentor nozzle?	Titanium, honeycomb, and corrugated sheet metal.
How are the convergent nozzle segments protected from heat?	By seals that have a heat-resistant coating.
The divergent exhaust nozzle is what kind of system?	Free-floating.
The divergent nozzle’s design allows it to achieve what type of optimum performance.	Subsonic and supersonic.
What positions the ballscrew actuators as requested by the DEEC?	CENC.
What power settings does the throttle lever position display?	Off, idle, mil, and max power settings.
What is the purpose of the cables in this system?	Transmit movement signals from the flight station to remote areas of the aircraft.
What motion does the sector box provide?	Linear motion.
Where is the sector box located?	Adjacent to the main fuel control.
What component contains a separate rotor and stator?	Stator generator.
What component controls and monitors the engine performance in primary mode?	DEEC.
(424) What component in the F100 monitoring system provides the operator information concerning how much (in percentage) the augmentor nozzle is opened or closed?
(424) Where is the fuel flow transmitter located in the F-15?
(425) What component in the F110 monitoring system performs diagnostics and fault isolates to line replaceable units?
(426) What component or components make up the engine monitoring system on the F119 engine itself? a. DEC.
(426) What component in the F119 engine monitoring system processes and stores vibration signals, oil debris signals, oil level signals, condition monitoring and fault information data in resident memory?
(427) What is the basic function of an augmentor (afterburner) when it is not operating?
(427) What is used to open and close flap-type and iris-type variable-exhaust nozzle systems?
(427) The most important advantage of using a C-D nozzle system is the
(427) What component heats augmentor fuel to provide better vaporization and combustion?
(427) Which system employs a small combustion chamber to ignite the fuel in the augmentor (afterburner) duct?
(427) What are the two main types of augmentor (afterburner) ignition systems?
(428) On the F100 engine augmentor, the divergent and convergent nozzle segments complete a four-bar linkage arrangement that controls the
(428) The F100 engine augmentor’s primary nozzle actuator is driven by cables from the
(428) The F100 engine augmentor’s exhaust nozzle is variable to control engine
429 What component in the electronic/mechanical controls is a fuel cooled digital computer that provides signals to the MFC for control of the front compressor speed (N1), rear compressor speed (N2), eng airflow, comb chamber pressure (Pb4) & FTIT

Created by: comso9o

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