At what point in an axial-flow turbojet engine will thw highest gas pressures occur? At the turbine entrance. Within the burner section. At the compressor outlet.
One function of the nozzle diaphragm in a turbine engine is to Decrease the velocity of exhaust gases. Center the fuel spray in the combustion chamber. Direct the flow of gases to strike the turbine blades at the desired angle.
The fan rotational speed of a dual axial compressor forward fan engine is the same as the low-pressure compressor. forward turbine wheel. high-pressure compressor.
The abbreviation Pt7 used in turbine engine terminology means the total pressure. pressure and temperature at station No. 7. the total pressure at station No. 7.
Which statement is true regarding jet engines? At the lower engine speeds, thrust increases rapidly with small increases in RPM. At the higher engine speeds, thrust increases rapidly with small increases in RPM. The thrust delivered per pound of air consumed is less at high altitude than at low altitude.
Some high-volume turboprop and turbojet engines are equipped whit two-spool or split compressors. When these engine are operated at high altitudes, the low-pressure rotor will increase in speed as the compressor load decreases in the lower density air. throttle must be retarded to prevent overspeeding of the high-pressure rotor due to the lower density air. low-pressure rotor will decrease in speed as the compressor load decreases in the lower density air.
Turbine nozzle diaphrams located on the upstream side of each turbine wheel, are used in the gas turbine engine to decrease the velocity of the heated gases flowing past this point. direct the flow of gases parallel to the vertical line of the turbine blades. increase the velocity of the heated gases flowing past this point.
Where is the highest gas pressure in a turbojet engine? At the outlet of the tailpipe section. At the entrance of the turbine section. In the entrance of the burner section.
What is the function of the stator vane assembly at the discharge end of a typical axial-flow compressor? To straighten airflow to eliminate turbulence. To direct the flow of gases into the combustion chambers. To increase air swirling motion into the combustion chambers.
The turbine section of a jet engine increases air velocity to generate thrust forces. utilizes heat energy to expand and accelerate the incoming gas flow. drives the compressor section.
When starting a turbine engine, a hot start is indicated if the exhaust gas temperature exceeds specified limits. an excessively lean mixture is likely to cause a hot start. release the starter switch as soon as indication of lights-off occurs.
In the dual axial-flow or twin spool compressor system, the first stage turbine drives the N(1) and N(2) compressors. N(2) compressor N(1) compressor.
When starting a turbine engine, a hung start is indicated if the engine exhaust gas temperature exceeds specified limits. fails to reach idle RPM. RPM exceeds specified operating speed.
A turbine engine is __________ (more or less) tolerant of improper starting procedures than a
reciprocating engine. more less.
The hazard area is considered to extend ____ feet behind an idling turbojet engine and____ feet behind one that is developing takeoff power. 100, 200 200, 100.
It is dangerous to be closer than ________ feet to the inlet ducts of any operating turbojet orturbofan engine. 25 35 45.
When a turbine engine is being started, the ignition sparks occur ________ (before or after) the fuel is sprayed into the combustion chambers. before after.
A proper light-up is indicated by a rapid rise in ________ . EGT EPR.
Three instruments that should be monitored when starting a turbine engine are:
a._____________
b._____________
c._____________ a. EGT indicator
b. tachometer
c. oil pressure gage a. EGT indicator
b. tachometer
c. EPR indicator.
A hot start is normally caused by a fuel-air mixture that is too _______ (rich or lean). rich lean.
A hung, or false, start is usually caused by a malfunction of the ___ ___ ____ (fuel control or starter). fuel control starter.
Two methods of determining when a turbine engine should be given a routine inspection are:
a.___________
b.___________ a. operating hours
b. operating cycles a. operating maintenace
b. operating cycles.
A sequence of events that consists of an engine start, takeoff, landing, and shutdown is called a/an____________________ . operating hours operating cycles operating maintenance.
Engines operated on an approved on-condition maintenance schedule ______ (are or are not)required to be overhauled when a specific number of operational cycles have been reached. are are not.
Trend monitoring compares the current operating conditions of an engine with standard base line conditions that were recorded by the engine __________ or __________ when the engine was run in the test cell. manufacturer, overhauler maintenance, overhauler manufacturer, maintenance.
Inspection of the inside of a turbine engine installed on the aircraft is possible by using a/an _________________ . borescope X ray.
Inspection of the inside of a turbine engine is done through __________ provided by the engine manufacturer. borescope parts fuel nozzle.
Before the ignition system is checked on a preflight inspection, the engine must be motored with the starterto move air through the engine and completely purge it of any __________ . fuel vapors oil vapors fuel.
Three components of the cold section of a turbofan engine are:
a. ---------------------------
b. ---------------------------
c. --------------------------- a. fan
b. compressors
c. diffuser a. fan
b. combustion chamber
c. air outlet a. diffuser
b. air inlet
c. air outlet.
Two indications of a dirty compressor are:
a. ---------------------------
b. --------------------------- a. high EGT
b. unsatisfactory acceleration a. low EGT
b. unsatisfactory acceleration a. high EGT
b. over-acceleration.
Two types of liquid washing of a turbine engine compressor are:
a. ________________________
b. ________________________ a. desalination washing
b. performance-recovery washing a. high pressure washing
b. desalination washing a. low pressure washing
b. desalination washing.
Two types of field cleaning of a turbine engine compressor are:
a. __________________
b. __________________ a. grit blasting
b. liquid washing a. gas washing
b. grit blasting a. grit washing
b. liquid washing.
The most frequently used method of field cleaning a compressor is to wash it with ________________ water and a cleaning fluid. demineralized pure.
If the engine is run for a performance-recovery compressor washing, it is operated at ______________(idle or takeoff) RPM. idle takeoff.
The amount of repair that can be made to a compressor blade is detailed in the ________. engine service manual aircraft service manual maintenance manual.
When the edges of a fan or compressor blade are repaired by blending, the damaged area is removed with a fine file, and the file marks are removed with a fine-grit __________. abrasive sponge abrasive stone.
It ________ (is or is not) recommended that bent compressor blades be straightened. is is not.
Five components in the hot section of a turbine engine are:
a. __________
b. __________
c. __________
d. __________
e. __________ a. fuel nozzles
b. combustion chambers
c. turbine inlet guide vanes
d. turbine wheels and blades
e. exhaust system a. air inlet
b. combustion chambers
c. compressors
d. turbine wheels and blades
e. air outlet.
A hot section inspection is normally required after a hot start or if, for any reason, the _______ has exceeded a specified limit. EGT EPR.
A hot section inspection normally requires that the engine be removed from the aircraft. This statement is ________ (true or false). true false.
A localized hot spot in a combustion chamber can be caused by a partially clogged _____________________ . fuel nozzle combustion chambers air inlet.
Stress-rupture cracks normally appear _______________ (perpendicular or parallel) to the leading and trailing edges of the turbine blades. perpendicular parallel.
Waviness of the leading or trailing edges of a turbine blade is normally an indication of ________________ . overheating overtempering.
Two critical measurements to be made of a turbine wheel during a hot section inspection are:
a. ____________
b. ____________ a. blade tip clearance
b. clearance between turbine wheel and exhaust cone a. blade clearance
b. clearance in turbine wheel.
Instruments installed in the aircraft _________ (are or are not) normally considered accurateenough for a preinspection and postinspection runup for a hot section inspection. are are not.
The information gained in a postinspection run-up after a hot section inspection is used as a base line for ________________ trend monitoring engine manufacturer's service manual present performance.
A lead pencil __________ (is or is not) an acceptable marker to use on hot section components. is is not.
When removing damage to the leading or trailing edge of a compressor blade, the file should be moved __________________ (parallel to or across) the length of the blade. parallel to across.
When the segment of a midspan shroud of a turbofan blade overlaps the segment on the adjacent blade, the
fan blade is said to be ___________. shingled knotted.
Fan blade shingling is normally caused by a ________ or by a/an ________condition. bird strike, overspeed ice, overspeed stresses, ice.
An engine that has had an overtemperature operation should be given a __________ inspection. hot section cold section.
For the maximum strength to be provided by a threaded fastener, the load applied when the fastener is
torqued must be _________ (greater or less) than the maximum load applied to the joint. greater less.
Torque wrenches used in aviation maintenance must be calibrated using masters that have their accuracy
traced to the ______________ . National Bureau of Standards or National Institute of Standards and Technology (NITS) American Society for Testing and Materials (ASTM) Society of Automotive Engineers (SAE).
Unless otherwise stated, the torque specified in torque tables is for clean and _______ _ (dry or lubricated) threads. dry lubricated.
When a torque wrench with a length of 15 inches is used with an adapter that increases the arm length by 3 inches, a torque of 200 inch-pounds will be produced at the adapter when the torque wrench indicates ________ inch-pounds. 166,7 176,5 185,5.
When a torque wrench with a length of 15 inches is used with an adapter that shortens the arm length by 3 inches, a torque of 200 inch-pounds will be produced at the adapter when the torque wrench indicates _____________ inch-pounds. 250 150 200.
A JetCal Analyzerffrimmer has three accurate master instruments. These are:
a. ___________
b. ___________
c. ___________ a. Tachometer
b. EGT indicator
c. EPR indicator a. Voltmeter
b. EGT indicator
c. Barometer.
When a turbine engine is trimmed, the ambient air temperature should be measured adjacent to the__________ engine air inlet engine compressors engine air outlet.
The ambient air temperature and barometric pressure must be corrected to--------------------conditions, in order to compare the instrument indications with the data furnished by the engine manufacturer. standard day, sea level 45°C, 15 mm Hg 12°F, 25 mm Hg.
When a turbine engine is trimmed, the aircraft should be headed----------------------- (into or across) the wind. into across.
The four basic rules for systematic troubleshooting are:
a. _______________
b. _______________
c. _______________
d. _______________ a. know the way the system should operate
b. observe how the system is operating
c. divide the system to find the trouble
d. look for the obvious problem first a. read the manual
b. unit the system
c. solve the bigger problem for ultimate.
What are the two basic elements of the turbine section in a turbine engine? Impeller and difuser. Hot and cold. Stator and rotor.
The function of the exhaust cone assembly of a turbine engine is to collect the exhaust gases and act as a noise suppressor. swirl and collect the exhaust gases into a single exhaust jet. straighten and collect the exhaust gases into a solid exhaust jet.
What are the two functional elements in a centrifugal compressor? Turbine and compressor Bucket and expander. Impeller and diffuser.
What is the first engine instrument indication of a successful start of a turbine engine? A rise in the engine fuel flow A rise in oil pressure. A rise in the exhaust gas temperature.
Some engine manufacturers of twin spool gas urbine engines identify turbine discharge pressure in ir maintenance manuals as Pt7 Pt2 Tt7.
The basic gas turbine engine is divided into two main sections: the cold section and the hot section.
(1) The cold section includes the engine inlet, compressor, and turbine sections.
(2) The hot section includes the combustor, diffuser, and exhaust sections.
Regarding the above statements, only No. 1 is true. only No. 2 is true. neither No. 1 nor No. 2 is true.
The recurrent ingestion of dust or other fine airborne particulates into a turbine engine can result in foreign object damage to the compressor section. the need for less frequent abrasive grit cleaning of the engine. erosion damage to the compressor and turbine sections.
Which of the following engine variables is the most critical during turbine engine operation? Compressor inlet air temperature. Compressor RPM. Turbine inlet temperature.
Standard sea level pressure is 29.00" Hg. 29.29" Hg. 29.92" Hg.
Using standard atmospheric conditions, the standard sea level temperature is 59°F. 59°C. 29°C.
What is the proper starting sequence for a turbojet engine? Ignition, starter, fuel. Starter, ignition, fuel. Starter, fuel, ignition.
A weak fuel to air mixture along with normal airflow through a turbine engine may result in a rich flameout. a lean die-out. high EGT.
What is used in turbine engines to aid in stabilization of compressor airflow during low thrust engine operation? Stator vanes and rotor vanes. Variable guide vanes and/or compressor bleed valves Pressurization and dump valves. .
In a turbine engine with a dual-spool compressor, the low speed compressor always turns at the same speed as the high speed compressor. is connected directly to the high speed compressor. seeks its own best operating speed. .
Generally, when starting a turbine engine, the starter should be disengaged after the engine has reached self-accelerating speed. only after the engine has reached full idle RPM. when the ignition and fuel system are activated.
What is the possible cause when a turbine engine indicates no change in power setting parameters, but oil temperature is high? High scavenge pump oil flow. Engine main bearing distress. Turbine damage and/oř loss of turbine effiiency.
If a turbine engine is unable to reach takeoff EPR before its EGT limit is reached, this is an indication that the fuel control must be replaced. EGT controller is out of adjustment. compressor may be contaminated or damaged. .
If the RPM of an axial-flow compressor remains constant, the angle of attack of the rotor blades can be changed by changing the velocity of the airflow. changing the compressor diameter. increasing the pressure ratio. .
Which of the following variables affect the inlet air density of a turbine engine?
1. Speed of the aircraft.
2. Compression ratio.
3. Turbine inlet temperature
4. Altitude of the aircraft.
5. Ambient temperature.
6. Turbine and compressor efficiency. 1,3,6. 1,4,5. 4,5,6.
Compressor stall is caused by a low angle of attack airflow through the first stages of compression. a high angle of attack airflow through the first stages of compression. rapid engine deceleration.
Which of the following is used to monitor the mechanical integrity of the turbines, as well as to check engine operating conditions of a turbine engine? Engine oil pressure Exhaust gas temperature Engine pressure ratio.
1) Airworthiness Directives are Federal Aviation Regulations and must be complied with unless specific exemption is granted
(2) Airworthiness Directives of an emergency nature may require immediate compliance upon receipt.
Regarding the above statements, only No. 1 is true. only No. 2 is true. both No. 1 and No. 2 are true. .
When must an Airworthiness Directive (AD) be complied with after it becomes effective? As specified in the AD. During the next scheduled inspection. At the next scheduled overhaul.
The breaking loose of small pieces of metal from coated surfaces, usually caused by defective plating or excessive loads, is called flaking chafing brinelling.
Each powerplant installed on an airplane with a Standard Airworthiness Certificate must have been type certificated. manufactured under the TSO system. originally certificated for that aircraft.
A severe condition of chafing or fretting in which a transfer of metal from one part to another occurs is called scoring. burning. galling.
Indentations on bearing races caused by high static loads are known as fretting. brinelling. galling.
Which of the following can inspect and approve an engine major repair for return to service? Certificated mechanic with airframe and powerplant ratings. Certificated mechanic with a powerplant rating. Certificated mechanic with inspection authorization.
What publication is used for guidance to determine whether a powerplant repair is major or minor? Airworthiness Directives. Federal Aviation Regulations Part 43, appendix A. Technical Standard Orders.
The airworthiness standards for the issue of type certificates for small airplanes with nine or less passenger seats in the normal, utility, and acrobatic categories may be found in the Federal Aviation Regulations, Part 23 Supplemental Type Certificate. Federal Aviation Regulations, Part 21. .
Which of the following contains approved data for performing a major repair to an aircraft engine? Engine Type Certificate Data Sheets Supplemental Type Certificates. Manufacturer's maintenance instructions when FAA approved.
What maintenance record(s) is/are required following a major repair of an aircraft engine? Entries in engine maintenance records and a list of discrepancies for the FAA. Entries in the engine maintenance record and FAA Form 337 Entry in logbook.
What publication contains the mandatory replacement time for parts of a turbine engine? Engine Manufacturers service instructions. Federal Aviation Regulation Part 43 Engine Manufacturer's maintenance manual.
What section in the instructions for continued airworthiness is FAA approved? Engine maintenance manual or section. Engine overhaul manual or section. Airworthiness limitations section.
Which of the following conditions is usually not acceptable to any extent in turbine blades? Cracks Pits. Dents. .
1) Serviceability limits for turbine blades are much more stringent than are those for turbine nozzle vanes
(2) A limited number of small nicks and dents can usually be permitted in any area of a turbine blade.
Regarding the above statements, both No. 1 and No. 2 are true. neither No. 1 nor No. 2 is true. only No. 1 is true.
The blending of blades and vanes in a turbine engine is usually accomplished only at engine overhaul should be performed parallel to the length of the blade using smooth contours to minimize stress points may sometimes be accomplished with the engine installed, ordinarily using power tools. .
What turbine engine section provides for proper mixing of the fuel and air? Combustion section Compressor section Diffuser section.
When starting a turbine engine, a hot start is indicated if the exhaust gas temperature exceeds specified limits. an excessively lean mixture is likely to cause a hot start. release the starter switch as soon as indication of light-off occurs. .
During inspection, turbine engine components exposed to high temperatures may only be marked with such materials as allowed by the manufacturer. These materials generally include 1. layout dye.
2. commercial felt tip marker.
3. wax or grease pencl
4. chalk.
5. graphite lead pencil. 1, 2, and 4. 1, 3, and 5. 2, 4, and 5.
What must be done after the fuel control unit has been replaced on an aircraft gas turbine engine? Perform a full power engine run to check fuel flow. Recalibrate the fuel nozzles. Retrim the engine.
If, during inspection at engine overhaul, ball or roller bearings are found to have magnetism but otherwise have no defects, they cannot be used again. are in an acceptable service condition. must be degaussed before use.
The basic gas turbine engine is divided into two main sections: the cold section and the hot section.
(1) The cold section includes the engine inlet, compressor, and turbirne sections.
(2) The hot section includes the combustor, diffuser, and exhaust sections.
Regarding the above statements, only No. 1 is true. only No. 2 is true. neither No. 1 nor No. 2 is true.
(1) Welding and straightening of turbine engine rotating airfoils does not require special equipment.
(2) Welding and straightening of turbine engine rotating airfoils is commonly recommended by the manufacturer
Regarding the above statements, only No. 1 is true. only No. 2 is true neither No. 1 nor No. 2 is true. .
Turbine engine components exposed to high temperatures generally may NOT be marked with
1. layout dye
2. commercial felt tip marker.
3. wax or grease pencil. gas
4. chalk.
5. graphite lead pencil. 1, 2, and 3. 3 and 5 4 and 5.
Who establishes mandatory replacement times for critical components of turbine engines? The FAA. The operator working in conjunction with the FAA. The engine manufacturer.
Three types of turbine blades are reaction, converging, and diverging. impulse, reaction, and impulse-reaction. impulse, vector, and impulse-vector.
Which statements are true regarding aircraft engine propulsion? 1. An engine driven propeller imparts a relatively
2. Turbojet and turbofan engines impart a relatively
3. In modern turboprop engines, neartly 50 percent of small amount of acceleration to a large mass of air large amount of acceleration to a smaller mass of air. the exhaust gas energy is extracted by turbines to drive the propeller and compressor with the rest providing exhaust thrust. 1,2, 3. 1, 2. 1, 3.
Where do stress rupture cracks usually appear on turbine blades? Across the blade root, parallel to the fir tree. Along the leading edge, parallel to the edge. Across the leading or trailing edge at a right angle to the edge length.
In which type of turbine engine combustion chamber is the case and liner removed and install as one unit during routine maintenance? Can Can annular Annular .
When the leading edge of a first-stage turbine blade is found to have stress rupture cracks, which of the following should be suspected? Faulty cooling shield Overtemperature condition Overspeed condition.
Turbine blades are generally more susceptible to on operating damage than compressor blades because of higher centrifugal loading exposure to high temperatures high pressure and high velocity gas flow.
Which of the following is the ultimate limiting factor of turbine engine operation? Compressor inlet air temperature. Turbine inlet temperature. Burner-can pressure. .
The recurrent ingestion of dust or other fine airborne particulates into a turbine engine can result in foreign object damage to the compressor section. the need for less frequent abrasive grit cleaning of the engine erosion damage to the compressor and turbine sections.
Jet engine turbine blades removed for detailed inspection must be reinstalled in a specified slot 180° away a specified slot 90° away in the direction of rotation. the same slot.
The highest heat-to-metal contact in a jet engine is the burner cans. turbine inlet guide vanes. turbine blades .
When aircraft turbine blades are subjected to excessive heat stress, what type of failures would you expect? Bending and torsion. Torsion and tension. Stress rupture.
Compressor field cleaning on turbine engines is performed primarily in order to prevent engine oil contamination and subsequent engine bearing wear or damage. facilitate flight line inspection of engine inlet and compressor areas for defects or FOD prevent engine performance degradation, increased fuel costs, and damage or corrosion to gas path surfaces .
Hot section inspections for many modern turbine engines are required only at engine overhaul. only when an overtemperature or overspeed has occurred on a time or cycle basis.
Hot spots on the tail cone of a turbine engine are possible indicators of a malfunctioning fuel nozzle or a faulty combustion chamber. a faulty igniter plug an improperly positioned tail cone. .
The procedure for removing the accumulation of dirt deposits on compressor blades is called the soak method. field cleaning. the purging process. .
Severe rubbing of turbine engine compressor blades will usually cause bowing. cracking. galling.
1) Accumulation of contaminates in the compressor of a turbojet engine reduces aerodynamic efficiency of the blades
(2) Two common methods for removing dirt deposits from turbojet engine compressor blades are a fluid wash and an abrasive grit blast.
Regarding the above statements, only No. 1 is true only No. 2 is true. both No. 1 and No. 2 are true.
Hot spots in the combustion section of a turbojet engine are possible indicators of faulty igniter plugs. dirty compressor blades. malfunctioning fuel nozzles.
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