Volume 3 (Engine Systems, Troubleshooting, Operation, Testing, Damage Analysis and Small Gas Turbine) Flashcards
Which subsystem is not included in the oil system?
Monitoring
What could be a cause of a compressor stall when there is a reduction or restriction of air at the air inlet?
Icing of the aircraft or the engine inlet
On the TF33 engine, where on the intermediate compressor case is the oil tank mounted?
Right
What type oil pump is on the TF33 engine?
Two section, single stage, gear driven
Which subsystem is not part of the oil indicating system?
Scavenge
What happens if the generator frequency becomes unstable?
Accuracy of electronic equipment is affected
A generator’s voltage output is roughly proportional to its
revolutions per minute
How many electrical phases does a TF33 engine driven generator produce?
3
The generator control unit provides system protection and control, and
voltage regulation
During the TF34 engine start, all fuel, up to a flow rate of how many pounds per square inch, will bypass the oil cooler?
350
The TF34 fuel pump consists of a low and high pressure stage, relief valve, and a
pressure regulating valve
How many pounds per square inch does the TF34 fuel pump boost stage increase the fuel inlet pressure?
80
When the red warning button is popped out on the fuel filter housing it indicates
fuel is bypassing the filter element
The splined coupling engine shaft transmits a signal of the core engine speed (the high pressure compressor and high pressure turbine speeds) to what fuel system component?
Main fuel control
Where is the excess metered fuel, from the servo and fuel pump discharge fuel, bypassed back to?
Inlet of the primary main pumping element
Metered fuel is supplied to the fuel distributor through the
quick engine change fuel flow transmitter and oil cooler
On engine shutdown, as fuel pressure decreases to below 40-60 pounds per square inch, the drain valve in the fuel distributor moves to the left
opening the drain, shutting off fuel flow to the distributor
On the TF34-100A engine, injector 13 is configured differently to
provide clearance between the injector and fuel control
Under hot fuel conditions at the combustor inlet, the altitude starting capability of the TF34-100A engine
is diminished
During start up, all fuel flow up to how many pounds per hour, is forced through the bypass line around the oil cooler?
350
Which type of fuel system is used in the TF34-100A engine to prevent spontaneous combustion of residual fuel after engine shutdown?
Shutdown drain system
The F108-CF-201 engine monitoring system data that is incorporated as part of the flight data recorder is used to determine
the need for maintenance before an engine failure occurs
Data that is recorded for each engine is downloaded and distributed via the
computer card
All of the options listed below are proper troubleshooting practices except
inspecting other areas after isolating trouble between points
In what format do technical orders present aircraft power plant and engine intermediate maintenance troubleshooting procedures?
Troubleshooting charts
To become an expert troubleshooter, you must
understand the function of each component within each system
On an F108 engine, which manifold is the anti-ice air supplied from?
Pneumatic
On an F108 engine, during which engine operation can the anti-ice valve be manually locked?
Shutdown or idling
The inlet duct used on multi engine subsonic aircraft (like the C-5 or C-17) has a diameter that progressively
increases from the front to the back
The compressor bleed system reduces the probability of a compressor stall in a dual-rotor engine by
reducing the amount of air available to the high-pressure compressor
What stage of the compressor airflow provides the cooling air for the turbine nozzle vanes?
First
On an F108-CF-100 engine, the direction of the variable bleed valve rotation is controlled by the
fuel gear motor
On an F108-CF-100 engine, which cable relays the variable bleed valve position to the main engine control as the valve approaches the commanded closed position?
Feedback
One type of aerodynamic blockage thrust reverser uses
vanes inside the duct to create swirling gases
How many core blocker doors are on the F117-PW-100 engine?
7
The function of the fuel pump on a F117 is to provide fuel directly to the fuel
control
What two components operate together to provide the thrust management system for the F117?
Electronic engine control and fuel control unit
A typical jet engine exhaust gas temperature indicating system contains thermocouples, thermocouple leads, an indicator, and a
resistor
What fuel-flow system component of a jet engine operates by using a water wheel concept?
Transmitter
Two units that work together to indicate the oil system is operating correctly is the oil pressure
transmitter and indicator
An oil pressure transmitter contains a mechanical section and a
synchronous unit
Where is the tachometer drive located that operates the high pressure compressor rotor tachometer generator?
Engine accessory section
What switch is pushed during an operational check of the fire warning system?
TEST
The test cell exhaust gas temperature (EGT) selector allows selection of
individual thermocouple inputs or an average of these inputs
Within how many revolutions per minute is the accuracy of the test cell low and high pressure compressor speed indicators?
2
What type of vibration causes unnecessary engine removals and unwarranted repairs?
Externally excited
During vibration analysis, frequency is usually measured in
cycles per second
Which type of vibration transducer is made up of certain ceramic compounds and natural crystals?
Piezoelectric accelerometer
The filter selector switch on the vibration analyzer
allows selection of the necessary filter to remove the natural vibration frequencies of a specific engine
What supports the fan and low-pressure turbine of a jet engine?
Bearings
Written instructions for safe flight-line vehicle operations are found in
Air Force Occupational, Safety, and Health Standard 91-100
Where are the two pressure gauges connected when conducting a jet engine oil system pressure check?
Output side of the main oil pump and the vent system
Which monitoring check allows you to start the auxiliary power unit without advancing the jet engine throttle to idle?
Dry
Where do the primary air silencers, that are designed to reduce the high-frequency turbine whine of a jet engine, fit on an aircraft?
On the aircraft fuselage
What forms most of the test bay portion sidewalks of a hush house?
Air inlet modules
What hush house piece of equipment allows for positioning of the removed engine directly in front of the augmentor tube?
Thrust stand
What establishes the time intervals for visual inspections and periodic maintenance requirements for the hush house?
Technical orders
What is the first step in engine testing?
Determine the type of engine maintenance performed before coming into the test facility
What are the two types of engine test cells currently used in the Air Force?
Fixed and portable
Engines are mounted in the fixed test cell on a thrust stand or are suspended
from a cradle mount
In the fixed test cell, where does the engine intake air come from?
Ceiling
On the portable test cell, the swivel pass at the bottom of the leveling jacks on the engine thrust trailer provide for all of the following except
support the thrust trailer at a high of 80 inches
The noise suppressor on a portable test cell is not equipped with
a fuel trailer
In what condition should an engine arrive at the engine test cell?
Operable with all known discrepancies corrected
What must be quickly moved to the “OFF” position should an unsatisfactory engine start occur in the engine test cell?
Engine throttle
What can an improperly rigged throttle linkage cause during an engine test cell run?
Engine overspeed
What action should be taken when making engine model and serial number entries on the test cell engine log sheet?
Verify these numbers against the engine data plate
What happens to jet engine efficiency as the operational hours increase?
Deteriorates due to wear
When making adjustments to any of the engine systems to bring them to a specification during a test cell run, adjust the device
up, not down to the required limit
How can the turbine outlet pressure total at station number 7 be varied during an engine test cell trim?
Adjusting the fuel control
When adjusting the fuel control during an engine test run, you can get the temperature and barometric pressure from equipment at the test cell site or from
the base air traffic control tower
What item is used with the applicable technical order to inspect a test facility?
Periodic inspection checklists
How often are service inspections conducted on an engine test cell?
Daily
Primary job aids that outline minimum inspection requirements are called
inspection work cards
Which inspection is a flight preparedness check?
Pre-flight
A basic post-flight inspection is completed
after the last flight of the flying period
What type inspection is completed on aircraft parts that require infrequent inspections?
Periodic
What inspection is completed on all newly assigned aircraft and engines?
Acceptance
Which inspection is conducted by maintenance personnel after an occurrence of a specific or unusual condition?
Special
A cold compressor stall that occurs at low revolutions per minute and is accomplished by a slight over temperature is called
an incipient
Where is a compressor blade most likely to fail?
Near the blade root
Turbine rotor blade failure usually occurs near what part of the blade?
Middle
What is the cause of most bearing failures?
Complete loss of lubrication
The pneumatic bleed air from a small gas turbine engine cannot be used to
inflate aircraft tires
On a gas turbine compressor power unit 165, where is the air compressed by the single-stage centrifugal compressor assembly discharged into?
Vaned deswirl assembly
How are the impeller wheel and two turbine wheels in the turbine section of the gas turbine compressor power unit 165 engine connected?
Couplings on a common shaft
What controls the turbine discharge temperature during a loaded condition on a gas turbine compressor power unit 165 engine?
Pneumatic thermostat
What component provides the shaft drives for the accessories group that is located in the forward housing of a gas turbine compressor power unit 165 engine?
Housing assembly set gear
Which signals are used by the fuel control unit to control engine operation on a gas turbine compressor power unit 165 engine?
Engine speed and pneumatic thermostat (load control) air pressure
Which component shuts the engine down if the oil pressure drops below the safe minimum operating limit on a gas turbine compressor power unit 165 engine?
Oil pressure switch
Where is air for the load control system extracted from on a gas turbine compressor power unit 165 engine?
Turbine plenum assembly
