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250 Cards in this Set
- Front
- Back
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1. How are conventional reciprocating engines classified |
Inline , v type ,radial, and opposed, or according to method of cooling: liquid or air cooled |
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2.What are the different types of piston rings |
Compression rings, oil control rings, scraper rings |
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3. What is the purpose of oil control rings |
Control the thickness of the oil film on the cylinder walls |
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4. What may be the result of installing Piston rings incorrectly |
Excessive oil consumption |
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5. What types of piston rods are commonly found In radial engine |
Master & articulating rod assembly |
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6. What types of bearings are in general is in recip engine |
"Plainbearings": used for crankshaft cam ring, connecting rods, and accessory drive shaft bearings
"Rolling bearings": used as mainly crankshaft main bearings
"Ball bearings": used for superchargers impeller shaft besrings
"Rockerarm bearings"
"Propeller thrust bearings" |
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7. What is the indication of valve blow by |
Indicated by hissing or whistle when pulling the prop through prior starting the engine |
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8. What is the purpose of using more than one spring for valve closing |
Valve spring will resonate (or surge) at certain engine speeds One spring can resonate, and it loses it's ability to keep valved closed, then the valve will start to float Using two springs (one inside another) eliminates the problem |
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9. What is the purpose of valve overlap |
Permits better volumetric efficiency and lowers the cylinder operating temp |
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10. Describe the inspection you would give the valve springs during engine overhaul |
Should be cleaned throughly and visually inspected for evidence of overheating ,cracks, broken ends, for compression strength |
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11. What is the purpose of using valves with sodium filled stem |
Used because it is an excellent heat conductor |
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12. What causes engine sudden stoppage |
Striking an object it engine seizure due to internal damage |
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13. What type inspection must be made after sudden stoppage of an engine due to striking an object |
Prop drive shaft must be checked for misalignment and the prop is checked for track |
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14. What is the purpose of crankshaft dynamic dampers used in aircraft engine |
Used to overcome forces that cause deflection of the crankshaft and torsional vibration Crankshaft vibration are reduced by placing floating dampers(weight) in the counterweight assembly. |
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15. How would you make a runout check on a crankshaft that is still installed In the engine |
-Remove prop from the shaft and attach a dial indicator gauge to the front of the crankcase. -adjust the position of gauge needle so that it is touching the shaft -turn engine through with starter, note any change in the gauge reading |
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16. What is detonation |
All fuel have critical limits and temperature and compression , and beyond this limit, they will ignite spontaneously and burn with explosive violence Instantaneous explosive burning of the last portion of charge is called detonation |
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17. During valve clearance adjustment in an R-2800 engine, why must you depress certain valves other than the ones being adjusted |
Prevents the cam from introducing errors in the valve clearance settings |
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18. What can be learned about the condition of an engine by studying the results of a compression check |
You can determine if the valves, piston rings, and pistons are adequately sealing the combustion chanmber. |
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19. How can a cold cylinder be located in a double row radial engine |
Checked with cold cylinder indicator, also known as magic wand To locate any cylinder that has a temperature lower than the normal operating temp |
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20. What instrument can be used to check cylinder bore out of roundness |
Dial indicator Telescope gauge Outside micrometer Inside micrometer |
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Turbine engines oral |
Turbine engines oral |
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1. What are the major components of a typical gas turbine engine |
-air inlet -compression section -combustion section -turbine section -exhaust section -accessory section |
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2. What are the two principle type of compressors used In turbojet aircraft |
Centrifugal flow Axial flow |
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3. What are three types of combustion chamber systems |
Can type Can annular type Annular type |
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4. What is the purpose of the interconnector tubes between can type combustion chambers |
Spread the flame to the combustion Chambers that are not equipped with igniter plugs during engine starting |
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5. What prevents burning of the liner walls in a can type combustion chambers |
Louvers |
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6. What types of damage may be found when inspecting compressor blades |
-dents -scratches -gouges -galling -burns -burrs -pitting -cracks |
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7. What is the location and function of the diffuser section in a turbine engine |
Located between the compressor section and burner cans Function to Change the high velocity compressor discharge air to static pressure |
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8. Where are stress rupture cracks lost likely to occur on turbine blades |
Appear as small hairline cracks on or across the leading or trialing edge or the blades, at right angle to the edge length |
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9. How are compressor blades attached to a disk type rotor |
Fitted by either bulb type or fir tree type. Then locked by means of screws, peening, locking wires, pins, keys |
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10. What is the purpose of the nozzle diaphragm or turbine nozzle |
Prepares the combustion mass airflow to drive the turbine rotor Also deflect the gasses so they strike the turbine at the most efficient angle for maximum turbine rotation |
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11. What is the major difference between a turboprop or a turbojet engine |
Turbo prop engine has more turbine stages than the turbojet engine Turboprop turbine must also drive a propeller |
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12. What is a turbofan engine |
Same as turboprop, in principle, except that the propeller is replaced by a duct enclosed axial flow fan |
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13. What is the effect of air density on the thrust of a turbine engine |
Determines the mass of air that is used by a jet engine. If density increases,thrust increases and vice versa Increase in air temperature entering an engine will cause a decrease in density and thrust |
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14. What are two most common types of thrust reverse |
Mechanical blockage type Aerodynamic blockage type |
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15. What is a split compressor system in a trubine engine |
Requires two concentric shafts joining the turbing stages to their respective compressora |
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16. What is one method of relieving thermal stress on a trubine disk |
Bleed cooling air back into the face if disk |
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17. What may be indication if a turbojet engine is out of trim |
Engine has high (EGT) at Target (EPR) for takeoff |
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18. What is free turbine |
Turbine wheel that drives a propeller or helicopter transmission |
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Engine inspection oral |
Engine inspection oral |
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1. What steps must be taken In order to prepare an aircraft for a 100 hour or annual inspection |
Remove or open all necessary inspection plates , access doors, fairing and cowling. Then throughly clean the aircraft and the engine |
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2. What may be used as a guide for a 100 hour inspection on an aircraft engine |
FAR part 43, appendix D |
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3. What additional inspection must be performed if the cylinder compression is weak |
Internal cylinder inspection for improper internal tolerance |
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4. where are the engine operating limitations found |
Aircraft specifications or type certificate data sheet |
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5. Where can a mechanic look to identify an aircraft engine |
Engine identification plate that is affixed to the engine at an accessable Location |
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6. What publication is needed to inspect an engine for conformity with specifications |
Engine specifications or engine TCDS |
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7. What type FAA approval is required when a change to an engine type design is not enough to require a new type certificate |
Supplemental type certificate is required |
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8. What type of FAA approval is required when a change is made to the engine principle of Operation |
New type certificate must be obtained |
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Engine instrument systems oral |
Engine instrument systems oral |
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1. What are the units in an engine fuel flow system |
Transmitter and indicator for each engine |
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2. Where is fuel flow transmitter located |
Mounted in fuel line between the engine driven pump and the carburator |
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3. What type of readout is indicated on a fuel flow system |
Record the fuel flow in pounds of fuel per hour |
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4. What is the reason for monitoring the fuel flow |
Operator can determine from the fuel flow indication whether the engine is operating at the correct fuel air mixture for a given power setting |
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5. What does a manifold pressure gauge indicate |
Absolute pressure in the intake manifold |
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6. What would be the effect of a broken manifold pressure gauge line |
Cause the gauge to indicate atmospheric pressure |
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7. what does the engine tachometer Indicate |
Crankshaft speed (rpm) |
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8. What are turbine engine tachometers designed to indicate |
Indicate Percent of rotor rpm |
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9. What is turbojet EPR |
Ratio between total turbine discharge pressure to total inlet pressure Indication of thrust being developed in the engine |
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10. What is the electric source for a cylinder head temperature gauge |
Connected to a thermalcouple attached to the cylinder which tests show to be the hottest on the engine |
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11. Where is carburator air temperature bulb located |
In air intake passage to the engine |
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12. How can a turbine E.G.T be checked without operating the engine |
Checking Resistance to the thermal couple and circuits |
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Engine fire protection systems oral |
Engine fire protection systems oral |
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1. What type of fire detector make are used for engine fire protection systems |
Overheat detector Rate of temperature rise Flame detector |
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2. When using a thermocouple type fire detector system what happens if the engine overheats slowly |
Thermocouple depends on rate of temperature rise Will not give a warning if the engine slowly overheats or a short circuit develops |
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3. Describe the operation of a Kidde continues loop fire detector system |
Has two wires embedded in a special ceramic core within an inconel tube One wire acts as an internal ground and the other wire is a hot lead that provides a current when the ceramic core materials change it's resistance with a raise in temperature |
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4. Where does a thermocouple fire detector system get it's electrical power to operate |
Power from the electrical system flows through the relay to the warning light |
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5. Describe a thermal switch fire detector system |
One or more lights that are energized by the aircrafts electrical system, heat sensitive thermal switch closes the circuit at a specific temperature |
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6. How are them all switches electrically connected In the circuit |
Parallel with each other but In series with the warning light |
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7. What is the most common cause of a false fire warning In a continuous loop detector system |
Dents, kinks, or crushed sensing element causing an internal wire to shore to the ground wire or outer tubing |
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8. What 2 methods are used to discharge fire extinghishing agents |
Mechanical and electrical |
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9. What method is used to release the fire extinghishing agent In a typical turbine engine fire protection system |
Equip the fire extinguishing containers with discharge valves that are operated by electrically discharge cartridges |
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10. What method is used to determine proper fire extinguisher container pressure |
Container gauge determines if pressure is between the prescribed minimum and maximum limits |
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11. What method other than the pressure gauge is used to indicate low agent pressure in a container |
Low pressure warning light in cockpit |
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12. What is the purpose the yellow and the red discharge plugs In a trubine engine fire extinguishing system |
Yellow : indicates pilot initiated discharge Red: indicates thermal discharge |
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13. What are two methods commonly used to distribute the fire extinguishing agent to the engine |
Perforated tubing or discharged nozzles |
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14. How does the fire extinguishing agent put out the fire |
Dilutes the atmosphere so that it will not support combustion |
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15. What does the HRD stand for in an HRD fire extinguishing system |
High rate of discharge |
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16. How is the fire extinghishing agent distributed from an HRD system |
Delivered from open end tubes |
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17. How long does it take to discharge the extinguishing agent In hrd system |
One to two seconds |
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18. Which type of fire detection system gives a more complete coverage of a fire hazard |
Continuous loop detector system |
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Engine electrical systems oral |
Engine electrical systems oral |
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1.how would you seat newly installed generator brushes to the commutator |
Face of the brushes must be shaped to provide an area of maximum contact with the commutator. |
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3. What units make up a DC generator three unit regulator |
Voltage regulator Current limiter Reverse current cutout |
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4. What method is used to control the voltage of an aircraft alternator |
Voltage regulator |
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5. What determines the frequency of the voltage of an alternator |
Speed of rotation of rotor and number of poles |
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6. How is alternator frequency maintained |
Installing a constant speed drive unit between the engine and the alternator |
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7. what are the three basic types of DC motors |
Serious Motors, shunt motors, compound motors |
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8. Name the parts of a DC motor |
Armature, the field, brushes, frame |
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9. What is a starter generator system used, used in many turbine engines |
Operates as a starter motor to drive the engine during starting. After engine has reached a self sustaining speed. It operates as generator to supply the electrical system power |
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10. What is American wire gauge system of designating electrical wire size |
Gauge number is assigned the wire according to it's cross sectional area. Smaller the gauge number the larger the wire |
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11. What is open wiring |
Any wire, wire group, or wire bundle not enclosed to conduit |
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12. What method is used to control the voltage of a DC aircraft generators |
Control the strength of the magnetic field |
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13. What are the causes of excessive arcing at the generator brushes |
Commutator is dirty, rough, out of round. More common cause of arcing is worn it binding brushes or the brush spring tension too low |
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14. When installating single wires or wire brushes, how much slack is normally allowed between supports |
Not exceed one half inch |
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15. What precaution should be taken when running wires close to heating ducts or exhaust stacks |
Insulated with a high temperature material |
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Lubrication systems oral |
Lubrication systems oral |
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1.what is the primary purpose of lubricant in an aircraft engine |
Reduce friction between moving parts |
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2. What is the most important property that aircraft reciprocating engine oil must possess |
Viscosity |
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3. What factors must be considered in determining the proper grade of oil to use in a specific engine |
Operating load Rotational speed Operating temperature |
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4. What is the purpose of the oil flow control valve |
Regulates the flow of oil either into or a around oil cooler |
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5. What are the main oil contaminates |
Gasoline , moisture , acid , dirt , carbon , and metallic particals |
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6. From what location on a reciprocating engine is the oil temperature usually taken |
Dry sump: oil temp bulb located anywhere In the oil inlet line between the oil tank and the engine. Wet sump: oil temp bulb located where it senses the temperature after oil passes through the oil cooler. |
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7. What do metallic particals on an oil screen indicate |
Internal failure of the engine |
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8. What could cause oil foaming |
Diluted oil, contaminated oil, oil level to high |
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9. What would be an indication of blocked oil cooler passages |
High oil temp |
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10. What would be an indication of an indequate oil supply |
Low oil pressure or High oil temp |
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11. What type of oil is used in turbine engine lubrication systems |
Specially developed synthetic oils |
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12. What are two types of oil coolers used In turbine engine lubrication systems |
Air cooled oil cooler Fuel cooled oil cooler |
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13. What is the meaning of oil flash point, fire point |
Flash point :Temperature at which the oil will begin to give off ignitable vapors Fire point: temperature at which there are sufficient vapors to support a continuous flame |
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14. What are the functions of engine oil In a reciprocating engine |
Lubrication, cools parts of the engine, helps seals combustion chamber, cleans engine by caring engine residues |
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15. What is the weight of aircraft engine oil |
7.5 pounds per US gallon |
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16. What is the purpose of an oil dilution system |
Thins the oil by introducing fuel into the lubrication system which makes cold weather starting easier |
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Ignition systems oral |
Ignition systems oral |
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1. What is a magneto |
Special type of engine driven AC generator that uses permanent magnets as a source of energy. Develops a high voltage that is used to fire the spark plugs |
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2. What is the purpose of the condenser in a high tension magneto electrical system |
Prevent arcing at the points and to hasten the collapse of the magnetic field around primary coil |
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3. What is the e gap position in a magneto |
When poles of the rotating magnet are a few degrees past neutral position |
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4. What are the three major circuits if a high tension magneto system |
Magnetic circuit Primary electrical circuit Secondary electrical circuit |
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5. What are the components of a high tension magnetic circuit |
•Permanent multipole rotating magnet, •soft iron core, •pole shoes |
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6. What happens when the primary breaker points open In a magneto |
Opening breaker points stops the flow of current in the primary coil. |
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8. What is a dual magneto ignition system |
Incorporates two magnetos In one housing and one rotating magnet and a cam are common to two sets of breakers points and coils |
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9. What is the difference between a low tension and a high tension ignition system |
High tension: produces high voltage spark in mag coul, sent to the correct spark plug by (built in distributor)
Low tension: uses (carbon brush type distributor) low voltage distributed to high tension transformer |
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10. When the ignition switch is off position, what is the condition of the primary circuit |
Completed through the ignition switch to ground |
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12. In a dual magneto ignition system, what part of the system is grounded when the ignition switch is placed in the right position |
Left magneto circuit will be grounded |
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13. What is internal timing of a magneto |
Adjusting breaker points to open when the poles of the rotating magnet are at the E gap position |
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14. What is the purpose of an impulse coupling used when a magneto |
To retard timing of the spark for starting the engine, then spin magneto rapidly to produce a hotter spark |
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15. What is staggered ignition timing |
Firing of one spark plug before the other one instead of firing them simultaneously |
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16. What is the proper spark plug reach |
When electrode end of the plug inside the cylinder is in the best position to achieve ignition |
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17. What type ignition is used in most turbine engines |
Electronic capacitor type ignition system |
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18. What is the function of the igniter plug in a turbine engine |
Provide discharge gap for the current which is stored in the capacitor |
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19. When are turbine engine ignition systems normally in use |
Required only for starting or restarting an engine |
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20. What are two types of igniter plugs |
Annular gap: long reach plug extends into the combustion chamber Constrained gap: short reach plug that does extend into the chamber because the spark does not remain close to the plug |
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Fuel metering systems oral |
Fuel metering systems oral |
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1. Where are the fuel spray nozzles located In a turbine engine |
Externally or internal on the combustion chamber |
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3. What engine variables are sensed by hydromechanical fuel control. |
-Power lever position, -rpm, -compressor inlet pressure or temperature, -burner pressure or compressor discharge pressure - egt& TIT |
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5. What type of fuel control unit is used in a turbine engine |
Both hydromechanical and electronic fuel control units are used today. Most commonly used is completely hydromechanical type |
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6. What is the purpose of a mixture control in a float type carburator |
Control fuel air mixture as air density changes with changes in altitude |
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7. What is the purpose of an accelerating system on a float type carburator |
When throttle is open rapidly, fuel air mixture will lean out momentarily, Charge of fuel from accelerating pump will temporarily enrich mixture in the venture |
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8. Describe the purpose and operation of venturi |
Performs three functions -proportions fuel air mixture -lowers pressure at discharge nozzle -limits airflow at full throttle |
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9. What it the function of metering jet |
To limit the fuel flow when the throttle valve is wide open |
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10. What is the fuel metering force in a float type carburator |
Differential pressure between the pressure in the float chamber and that at the nozzle |
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11. What will be the result of using excessively rich idle mixtures |
Cause carbon fouling of your spark plug |
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12. What is the purpose of the (economizer) system In a float carburator |
A valve which is closed at throttle settings below 60% to 70% of rated power but provide additional fuel for cooling the engine to prevent detonation at higher throttle setting |
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13. Where does a pressure injuction carburator obtain fuel pressure |
From the boost pump for starting and from the engine driven fuel pump for normal operation if the engine |
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14. What operates an automatic mixture control on a pressure carburator |
Contains sealed bellows that expands or contracts with changes in atmospheric pressure, Movement of the Bellow operates a tapered needle that controls the impact air pressure into the A chamber of carburator |
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15. In what position do you place the mixture control of a pressure injection carburator to stop the engine |
Idle cutoff position |
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16. What rpm indication should result when the mixture control is placed in the idle cutoff position when the idle mixture is set correctly |
Slight increase in rpm followed by rapid drop of rpm to zero |
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17. What is the purpose of filling a pressure injection carburator full of fuel and allowing it to soak for a period of eight hours prior to installation |
Done to soften the diaphragms and make them as pliable as they we're when the carburetor was originally calibrated |
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18. What are three types of carburator icing |
Throttle icing Impact icing Fuel evaporator icing |
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19. What is the typical fuel pressure in a float type carburator |
3-5 psi |
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Engine fuel system oral |
Engine fuel system oral |
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1. What is the purpose of strainers Ina fuel system |
used to prevent foreign matter from entering carburator |
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2. What is the purpose of fuel selector valves |
Means of shutting off fuel flow, for tank and engine selection, for crossfeed , fuel transfer |
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3. What should be looked for when inspecting an engine driven fuel pump |
Fuel leaks, security of mounting |
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4. What is the purpose of engine driven fuel pump |
Deliver continuous supply of fuel at the proper pressure at all times during engine operation |
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5. What type of fuel pump is generally used with large recip engines |
Positive displacement rotary vane type pump |
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6.what happens to the excess fuel not required by the engine in a constant displacement pump |
Pressure relief valve open and fuel is routed back to the inlet side of pump |
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7. What is the most common type of fuel boost pump |
Electrically driven centrifugal type pump |
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8. What is the purpose of the bypass valve in the engine driven fuel pump |
Provides path around the pump vanes for starting engine and to allow fuel to bypass the pump in case of pump failure |
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9. What is the purpose of using boost pump in fuel system |
-provide fuel pressure for starting - pressurize lines to prevent vapor lock -transfer fuel from one tank to another |
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10. What are the three general causes of vapor lock |
-Low fuel pressure, -high fuel temperature, - excessive fuel turbulence |
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12. What category is a turbine engine driven gear type pump |
Constant displacement |
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13. What type fuel pump can be made to vary the fuel flow at any speed |
Variable displacement pump |
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14. What part of a gas turbine engine fuel system is very suspectibal to the formation of ice |
Fuel filter |
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15. How is the engine fuel system protected from ice formation |
Use of fuel heaters |
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16. What is a micrometer fuel filter proveided with bypass valve as a necessary saftey factor |
Small openings in this type filter make it very suspectibal to clogging |
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Engine induction systems oral |
Engine induction systems oral |
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1. What are the three major parts of a recip engine induction system |
-Airscoop and ducting, -carburator, and -intake manifold |
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2. What effect does induction system icing have on engine performance |
Cause engine to act erratically and lose power |
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3. What method is used to prevent or remove induction system ice in a recip engine |
Use of heated air |
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4. How is ice cleared in some aircraft induction systems if the carburator heat is too low to clear the ice |
Fluid such as alcohol,anilol, mersol is sprayed into induction system ahead of the carburator |
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5. What engine indication can be the result of a dirty air filter |
Low power |
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7. Carburator throttle ice is most likely to form when the throttle is in which position |
Part throttle position, when throttle is near closed position |
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8. What are two general classifications of superchargers used in recip engine induction system |
Classified as internally driven or externally driven (turbocharger) supercharger system |
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9. What is the purpose of a distribution impeller in a supercharger |
Designed to break up the fuel globules into finer particles for better distribution to the cylinders |
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10. How does an internally driven supercharger boost air pressure |
High speed impeller is driven through a gear train from the crankshaft at a gear ratio that carries from 6:1 to 12:1 |
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11. Where does an externally driven supercharger get it power |
Exhaust gases directed against turbine, that why it's commonly called turbo charger |
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12. What unit regulates the amount of exhaust gases to the turbine of a turbocharger |
Waste gate |
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13. What type of power is used to control the position of the turbocharger waste gate on some engines |
Oil pressure to an actuating piston |
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Engine cooling systems oral |
Engine cooling systems oral |
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1. What is the most common means of regulating the cooling air flow through a radial engine |
Cowl flaps |
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2. What is the purpose of the fins on engine cylinders |
Increase surface size of cylinder for cooling |
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3. What other engine characteristics are designed to aid in engine cooling besides cooling fins |
Cowling and baffels are designed to force air over the cylinder cooling fins |
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4. Why is the open and close adjustment during installation of cowl flaps important |
Cowl flaps are set for tolerance that will permit them to open and close the correct amount to keep cylinder head temp within allowable limits |
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5. What should be done to cylinders when too much of the cooling fin area broken off |
Properly replaced because it cannot cool properly and a hot spot will develop |
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6. When should cowl flaps be kept in the fully open position |
Normally during all ground operations |
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7. What publication should be referred to before repofiling cylinder cooling fins |
Manufacturers service or overhaul Manuel should be used to obtain the allowable limits |
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8. What power sources are used to operate the cowl flaps |
Operated by electrical power, hydraulic power, manually |
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9. What is the purpose of blast tubes that are built into the baffles on a recip engine |
Direct jets of cooling air onto the rear Spark plug elbows of each cylinder to prevent overheating of the ignition loads |
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10. What are the main reasons that excessive heat in an recip engine is undesirable |
Excessive heat Shortens the life of the engine parts, impairs lubrication, and affects combustion |
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11. Describe the augmentor system |
Consists of two pairs of tubes running from engine compartment to the rear of an nacelle. Exhaust gas collector feeds exhaust gases into the inner augmentor tubes. Air that has passed over the engine is fed into the outer tubes where it is heated by the exhaust tubes and then expelled to mix with the exhaust gases. The heating of the air causes it to form a high temp low pressure jet like exhaust which draws additional cooling air over the engine. The heated air is sometimes used for the cabin heating defrosting and anti icing |
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12. What is the source of air that is directed to engine bearings for cooling |
To bleed air from the compressor section of the engine |
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13. What is the purpose of installation of the exhaust duct of a turbine engine |
Reduce temperature of the structure in the vicinity of the exhaust duct or afterburner and to eliminate the possibility of fuel or oil coming into contact with the hot parts of the engine |
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14. What types of materials are used to make insulation blankets for trubine engines |
Made of stainless steels with layers of aluminum foil, fiberglass, silver foil |
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15. What areas of a turbine engine are cooled by the secondary air passing through the engine |
Combustion Chambers and the turbines |
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16. What is the purpose of and engine cowling |
Streamlines the engine to reduce drag and it forms an envelope around the engine which forces air around and between the cylinders to cool them |
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17. What is the purpose of an oil cooler bypass valve |
Allows the thick oil to bypass the cooler when the oil is cold |
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Engine exhaust systems oral |
Engine exhaust systems oral |
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1. What are two types of recip engines exhaust systems |
Short stack system and the collector system |
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2. What are the possible hazards of exhaust system failure |
Can result in carbon Monoxide poisoning of the crew and passengers partial or complete loss of engine power and an aircraft fire |
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3. What type exhaust system generally used on low powered non supercharged engines |
Short (open) stack system |
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4. What type of exhaust system is used on turbocharged engines |
Exhaust collector system |
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5. What type of exhaust system creates a higher exhaust back pressure |
Collector system |
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6. What is the purpose of reciprocating engine exhaust system |
Dispose of high temperature , noxious gases that are discharge by the engine |
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7. What happens when lead, zinc, or galvanized marks are made of an exhaust system |
Mark is absorbed by the metal when it is heated and causes a change in the molecular structure of the metal |
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8. What type of visual indication can usually be seen in the area of an exhaust leak |
Exhaust leaks usually leave flat grey or sooty black streaks on the pipes In the area of the leak |
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9. How are ceramic coated exhaust stacks cleaned |
Degresing only |
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10. What is the usual cause of muffler and heat exchanger failure |
Caused by thermal and vibration cracking or ruptures in areas of stress concentration |
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11. Where are exhaust manifold and stack failures most likely to occur |
Welded or clamp points in the system |
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12. What is a common cause of the waste gate unit malfunctioning in a turbocharger system |
Carbon build up, causing the waste gate valve to stick in the closed position |
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13. What factors are affected if the area of the exhaust nozzle of a turbine engine is changed |
Both engine performance and exhaust gas temp |
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14. What are the probes In a turbine exhaust tailpipe used for |
To measure exhaust gas temp |
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15. Why do you disassemble and inspect the collector type |
Exhaust system failure can result in carbon monoxide poisoning of crew and passengers |
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16. What is the purpose of the waste gate on a turbocharger exhaust |
Controls the amount of exhaust gases forced through the turbocharger turbine. When gate is fully closed, all gases must pass through the turbine |
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Propellers oral |
Propellers oral |
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1. What is the purpose of a propeller |
Create thrust and either push or pull the airplane through the air |
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2. What are two types of propeller configurations |
Tractor type and pusher type |
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3. What type of propeller has the blade angle built into the propeller and cannot be changed |
Fixed pitch propeller |
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4. What is the purpose of the metal tipping on a leading edge of a wooden propeller |
Protect prop from damage caused by flying particles in the air during landing, taxiing, takeoff |
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5. What tools is used to determine prop blade angle |
Universal propeller protractor |
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6. What are the aerodynamic forces and loads acting in a rotating prop blade |
Acted upon by centrifugal, twisting, bending of forces |
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7. What is the meaning of propeller blade back and face |
-Cambered or curved side of prop blade is called blade back -flat side of the prop blade is known as the blade face |
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8. What should be used to clean aluminum and steel propeller blades and hubs |
Suitable cleaning solvents using brush or cloth |
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9. What positions are used on a balance stand to check a two bladed prop for static balance |
Vertical position, horizontal position |
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10. When centrifugal force acts on the counterweights of a hydraulic counterweight propeller , it tends to rotate the blades in which direction |
Centrifugal force tends to increase the blade pitch |
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11. Why do you put blades of a counterweight propeller into high pitch before stopping the engine |
Prop has moveable cylinder that slides over a fixed piston. In the low pitch position, the cylinder it outboard and the Piston is exposed to the open air. But in the high position is protected from dirt and moisture in the air. |
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12. Why are cones installed on splined shafts with a prop |
Cones center the prop on the shafts as they are forced toward each other by the tightening of the retaining nut |
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13. How is feathering accomplished on a constant speed counterweight propeller |
Releasing governor oil pressure allows counterweight and feathering spring to move the blades to the feathered position |
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14. What types of systems are used for deicing propeller |
Fluid or electrical deicing systems |
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15. What is the purpose of a slinger ring on some propeller installation |
Fluid under pressure of centrifugal force is transferred through a tube to the propeller blades |
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16. What is blade tracking |
Process of determining the position of the tips of the propeller blades relative to each other |
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17. Do the counterweight on a constant speed propeller increase or decrease the blade angle |
Used to increase the pitch of blades |
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18.what should be adjusted if a pilot requests 50 more rpm on a constant speed propeller equipped aircraft engine |
Adjust governors prop lever set screw |
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Auxiliary power units oral |
Auxiliary power units oral |
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1. What is the typical relationship between an aircraft axillary power unit and the engine driven generator |
They are identical |
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2. Where does the apu fuel supply normally come from |
Airplanes main fuel supply |
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3. How is the apu rotated during start up |
Electric starter |
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4. What is the function of an APU air inlet plenum |
Stabilize the pressure of the air before it enters the compressor |
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5. When operating at high loads what is the speed of an APU |
Remains at or near rated speed regardless of the load condition |
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6. What is the effect of the pneumatic power when being used in conjunction with maximum apu shaft power output |
Pneumatic loading will be automatically modulated to maintain a safe egt |
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7. Before shutdown, how would apu cooling be accomplished |
Closing the bleed air valve |
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8. When is most of the load placed on an apu |
When bleed air is opened |
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9. What regulates fuel scheduling during apu start and under varying pneumatic bleed and electrical loads |
Maintained automatically by the apu fuel control system |
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10. What I'd the primary function of the load compressor on APU equipped with a free turbine and load compressor |
Provide bleed air for aircraft pneumatic systems |
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11. What three Conditions are required to fire plugs in a cylinder when the position is in the prescribed position |
•Magneto magent poles must be in E gap, •breaker points must open, •distributor rotor must be aligned with the distributor electrode for that cylinder |
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6. What is the danger of using carburator heat when operating at high power settings |
Detonation and possible engine failure |
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2. Where is the generator rating and performance data located |
Stamped on data plate attached to the generator |
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7. What is the piston position when the spark occurs in a cylinder |
Piston is a specified number of crankshaft degrees before top dead center of compression stroke |
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2.Name heat sources for the operation of fuel heaters used in turbine engine |
Turbine engine fuel heaters operates as heat exchanger Fluid lines routed through fuel heater If bleed air is used as a heat source it's called air to liquid heat exchanger When oil is used it's called liquid to liquid heat exchanger |
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4. What are two most commonly used carburators in small reciprocating engines |
Float type carburator and pressure type carburator |
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11. Turbine engine fuel pumps may be divided into what two distinct system categories |
constant displacement and variable displacement |
