DGCA & EASA Module 15 : Part-18 Engine Monitoring and Ground Operation Question

DGCA & EASA Module 15 : Part-18 Engine Monitoring and Ground Operation Question-Answer

1. Who establishes the recommended operating time between overhauls (T.B.O) of a gas turbine engine.

A. The engine manufacturer.

B. The operator (utilizing manufacturer data and trend analysis) working in conjunction with the Airworthiness Authority.

C. The Airworthiness Authority alone.

Ans : The operator (utilizing manufacturer data and trend analysis) working in conjunction with the Airworthiness Authority.

Explanation: Jeppesen A&P Powerplant Textbook 3-27.

2. What is the first engine instrument indication of a successful start of a turbine engine?.

A. A rise in oil pressure.

B. A rise in the engine fuel flow.

C. A rise in the exhaust gas temperature.

Ans : A rise in the exhaust gas temperature.

Explanation: NIL.

3. A hung start is indicated by the.

A. exhaust gas temperature exceeds specified limits.

B. fails to reach idle RPM.

C. RPM exceeds specified operating speed.

Ans : fails to reach idle RPM.

Explanation: Jeppesen A&P Powerplant Textbook 4-7.

4. The blending of blades and vanes in a turbine engine.

A. may sometimes be accomplished with the engine installed, ordinarily using power tools.

B. should be performed parallel to the length of the blade using smooth contours to minimize stress points.

C. is usually accomplished only at engine overhaul.

Ans : No Answer.

Explanation: NIL.

5. 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.

A. layout dye, commercial felt tip marker or chalk.

B. layout dye, commercial felt tip marker, wax or grease pencil.

C. layout dye, commercial felt tip marker, wax or grease pencil, chalk or graphite lead pencil.

Ans : layout dye, commercial felt tip marker or chalk.

Explanation: Jeppesen A&P Powerplant Textbook 4-26.

6. When the leading edge of a first stage turbine blade is found to have stress rupture cracks, which of the following should be suspected?.

A. Faulty cooling shield.

B. Over speed condition.

C. Over temperature condition.

Ans : Over temperature condition.

Explanation: Jeppesen A&P Powerplant Textbook 4-25.

7. A magnetic chip detector inspection should be carried out.

A. within a specified time from shut down.

B. with engine cold.

C. with engine running.

Ans : within a specified time from shut down.

Explanation: A.L.F 502 and 507 engines on 146/R.J specify that the engine M.C.D be checked after 20mins but before 2 hrs since shut down.

8. What is the proper starting sequence for a turbojet engine?.

A. Starter, ignition, fuel.

B. Starter, fuel, ignition.

C. Ignition, starter, fuel.

Ans : Starter, ignition, fuel.

Explanation: Jeppesen A&P Powerplant Textbook 4-7.

9. Foreign object damage on a compressor, when boroscoping, is indicated by.

A. tip curl.

B. nicks and scores.

C. flats.

Ans : nicks and scores.

Explanation: Jepperson Gas Turbine Powerplants Page 5-13 refers.

10. Turbine blades are generally more susceptible to operating damage than compressor blades because of.

A. higher temperature stresses.

B. higher centrifugal loading.

C. high pressure and high velocity gas flow.

Ans : higher temperature stresses.

Explanation: NIL.

11. A magnetic chip detector detects.

A. particles held in suspension.

B. particles which are too small for the naked eye.

C. ferrous particles only.

Ans : ferrous particles only.

Explanation: Jepperson Gas Turbine Powerplants Page 6-26 refers.

12. A cool-off period prior to shutdown of a turbine engine is done to.

A. prevent vapor lock in the fuel control and/or fuel lines.

B. prevent seizure of the engine bearings.

C. allow the turbine wheel to cool before the case contracts around it.

Ans : allow the turbine wheel to cool before the case contracts around it.

Explanation: Jeppesen A&P Powerplant Textbook 4-9.

13. When starting a turbine engine, the starter should be disengaged.

A. only after the engine has reached full idle RPM.

B. when the ignition and fuel system are activated.

C. after the engine has reached self-sustaining speed.

Ans : after the engine has reached self-sustaining speed.

Explanation: Jeppesen A&P Powerplant Textbook 4-7.

14. What should be done initially if a turbine engine catches fire when starting?.

A. Continue starting attempt in order to blow out the fire.

B. Continue engine start rotation and discharge a fire extinguisher into the intake.

C. Turn off the fuel and continue engine rotation with the starter.

Ans : Turn off the fuel and continue engine rotation with the starter.

Explanation: Jeppesen A&P Powerplant Textbook 4-7.

15. A turbine engine hot section is particularly susceptible to which kind of damage?.

A. Scoring.

B. Galling.

C. Cracking.

Ans : Cracking.

Explanation: NIL.

16. If a turbine engine is unable to reach takeoff E.P.R before its E.G.T limit is reached, this is an indication that the.

A. fuel control must be replaced.

B. E.G.T controller is out of adjustment.

C. compressor may be contaminated or damaged.

Ans : compressor may be contaminated or damaged.

Explanation: NIL.

17. Which of the following engine variables is the most critical during turbine engine operation?.

A. Compressor RPM.

B. Turbine inlet temperature.

C. Compressor inlet air temperature.

Ans : Turbine inlet temperature.

Explanation: NIL.

18. With the engine running at idle, the E.P.R system reads just over 1.

A. The system has failed and needs attention.

B. The system needs re-calibration back to '1'.

C. This is a normal condition and does not need attention.

Ans : This is a normal condition and does not need attention.

Explanation: E.P.R with the engine shut down should read 1. At idle a very small pressure increase occurs in the jet pipe.

19. The recurrent ingestion of dust or other fine airborne particulates into an engine can result in.

A. the need for less frequent abrasive grit cleaning of the engine.

B. foreign object damage to the compressor section.

C. erosion damage to the compressor and turbine sections.

Ans : erosion damage to the compressor and turbine sections.

Explanation: NIL.

20. When the engine is not running, and engine blanks are installed. The E.P.R gauge shows 1.0, then.

A. the transmitter is faulty.

B. the receiver is faulty.

C. it is normal.

Ans : it is normal.

Explanation: Jepperson Gas Turbine Powerplant Page 12-17 Figure 12-12A.

21. Which of the following may be used to accomplish internal inspection of an assembled gas turbine engine?.

A. Ultrasound, and fluorescent penetrant and ultraviolet light.

B. X-ray and a borescope.

C. Infrared photography and fluorescent penetrant and ultraviolet light.

Ans : X-ray and a borescope.

Explanation: NIL.

22. Run down time is indicative of.

A. an F.C.U malfunction.

B. compressor malfunction.

C. the freedom of rotation of the compressor.

Ans : the freedom of rotation of the compressor.

Explanation: Short run down time is indicative of bearing failure.

23. A hung start or false start is one in which.

A. light up' occurs, but the RPM does not increase.

B. there is no 'light up'.

C. the engine does not rotate.

Ans : light up' occurs, but the RPM does not increase.

Explanation: Jeppesen Gas Turbine Powerplants Page 10-1 Refers.

24. What would be the possible cause if a gas turbine engine has high exhaust gas temperature, high fuel flow, and low RPM at all engine power settings?.

A. Fuel control out of adjustment.

B. Loose or corroded thermocouple probes for the E.G.T indicator.

C. Turbine damage or loss of turbine efficiency.

Ans : Turbine damage or loss of turbine efficiency.

Explanation: Jeppesen A&P Powerplant Textbook 4-5.

Click Here For : DGCA & EASA Module 15 : Part-19 Engine Storage, Preservation & Powerplant Installation Question

25. In regard to using a turbine engine oil analysis program, which of the following is NOT true?.

A. It is best to start an oil analysis program on an engine when it is new.

B. A successful oil analysis program should be run over an engine's total operating life so that normal trends can be established.

C. Generally, an accurate trend forecast may be made after an engine's first oil sample analysis.

Ans : Generally, an accurate trend forecast may be made after an engine's first oil sample analysis.

Explanation: NIL.

26. Which of the following is the least likely indication of a main bearing failure?.

A. High oil consumption.

B. High oil temperature.

C. High oil pressure.

Ans : High oil pressure.

Explanation: Low oil pressure would indicate bearing failure not High!.

27. After shutdown, flames are present in the exhaust pipe. The probable cause is.

A. a defective fuel control unit (F.C.U).

B. a defective pressurizing and dump valve.

C. a defective H.P cock.

Ans : a defective pressurizing and dump valve.

Explanation: Jeppesen Gas Turbine Powerplant Page 7-56 refers.

28. If the L.P cock is used to shutdown an engine.

A. the F.C.U will continue to function.

B. flames will appear in the exhaust.

C. the H.P fuel pump will run dry.

Ans : the H.P fuel pump will run dry.

Explanation: The L.P cock is normally aircraft mounted. The engine will run until the H.P fuel pump runs dry.

29. When accelerating from 'light-up' to ground idling speed, the E.G.T will.

A. remain constant.

B. increase above idle value then decrease to normal.

C. decrease below idle value then increase to normal.

Ans : increase above idle value then decrease to normal.

Explanation: All Gas Turbines tend to overfuel until the RPM increases sufficiently to supply correct idle air flow.

30. A gas turbine engine is stopped by closing.

A. L.P cock.

B. H.P cock.

C. throttle valve.

Ans : H.P cock.

Explanation: Rolls Royce The Jet Engine Page 110 refers.

31. A 'wet start' is indicated by.

A. no temperature indication.

B. low RPM.

C. a prolonged cranking period.

Ans : no temperature indication.

Explanation: Due to lack of ignition.

32. The engine accelerates to idling by.

A. gas flow.

B. combined efforts of starter motor and gas flow.

C. starter motor.

Ans : combined efforts of starter motor and gas flow.

Explanation: NIL.

33. An oil emission spectrometer measures.

A. particles in suspension.

B. particles on the surface.

C. specific gravity of the oil.

Ans : particles in suspension.

Explanation: The colour of the spectrum produced upon burning the oil indicates parts per million of all metallic elements contained in the sample.

34. A broadband vibration reading indicates.

A. the total vibration sensed by the transducer.

B. the peak allowable vibration.

C. the N1 vibration.

Ans : the total vibration sensed by the transducer.

Explanation: Broadband is the total of all the vibrations sensed.

35. Vibration analysers determine which component is vibrating by analysing.

A. voltage.

B. amplitude.

C. frequency.

Ans : frequency.

Explanation: The faster the compressor shafts rotate the higher the frequency.

36. High frequency vibration.

A. causes engine components to crack.

B. energises air particles prior to compression.

C. can give an indication of a fluctuating (E.P.R).

Ans : causes engine components to crack.

Explanation: The more vibration cycles the nearer to failure the component will become.

37. Engine oil sampling analysis is taken.

A. after engine shut down.

B. at specific time after engine shut down.

C. when oil level is high.

Ans : at specific time after engine shut down.

Explanation: Jeppesen A&P Powerplant page 9-35 refers.

38. With external power applied, the engine will not run up to idle after reaching starting speed. The likely fault would be with the.

A. Fuel Control Unit.

B. clutch.

C. battery.

Ans : Fuel Control Unit.

Explanation: Once an engine has reached starter cut out speed the only thing that can stop it accelerating is underfuelling.

39. When running down an engine.

A. it should be done as slowly as possible to assist thermal stress.

B. it should be done as quickly as possible to stop excess of fuel gathering.

C. it should be done as slowly as possible to reduce thermal stres.

Ans : it should be done as slowly as possible to reduce thermal stress.

Explanation: Jeppesen Aircraft Gas Turbine Powerplant Page 14-2 refers.

40. What may be an indication of a bleed valve stuck in the closed position?.

A. Over speed.

B. Low E.G.T reading.

C. Compressor stalling at low RPM.

Ans : Compressor stalling at low RPM.

Explanation: A closed bleed valve at low RPM means the compressor has too much air to handle, hence it may stall or surge.

41. Excessive E.G.T can.

A. cause N.G.V to creep.

B. cause damage to turbine.

C. cause damage to jet pipe.

Ans : cause damage to turbine.

Explanation: The turbine is the highest stressed component in the engine.

42. A jet engine has a high oil temperature but all other power parameters are normal. The probable cause is.

A. a large quantity of oil being returned to tank.

B. gear box leakage.

C. a main bearing in distress.

Ans : a main bearing in distress.

Explanation: Oil systems cool as well as lubricate.

43. When cleaning salt from a compressor.

A. use water then manufacturer's cleaning solution.

B. use water at low power then water at high power.

C. never use water, use only the recommended solution.

Ans : use water at low power then water at high power.

Explanation: Jeppesen Aircraft gas turbine Powerplants Page 5-5 refers to desalination washes using water only.

44. A hot start refers to.

A. early ignition.

B. high E.G.T before idle RPM is achieved.

C. too much fuel being supplied.

Ans : high E.G.T before idle RPM is achieved.

Explanation: A hot start is defined as an overtemping of the engine as the engine starts. It may be caused by overfuelling, but not necessarily.

45. If a compressor surge occurs, it is recognized by.

A. coughing in the compressor and vibration.

B. fluctuating RPM and fuel flow.

C. fluctuating E.G.T and thrust.

Ans : coughing in the compressor and vibration.

Explanation: Whilst E.G.T and RPM will fluctuate, fuel flow will not and thrust cannot be measured. Therefore coughing and vibration is the correct answer.

46. Cracks may occur in hot section components of a turbine engine if they are marked during inspection with.

A. a lead pencil.

B. chalk.

C. layout dye.

Ans : a lead pencil.

Explanation: Graphite based markers can cause intergranular corrosion. See Jeppesen Gas Turbine Powerplants Page 5-31.

47. What must not be used during an engine compressor wash?.

A. Chlorine.

B. Desalinization solution.

C. Crushed almond.

Ans : Chlorine.

Explanation: By elimination b is correct. Crushed almond and desalination solutions are accepted compressor wash applications.

48. Trend monitoring of spectrometric oil analysis is carried out how often?.

A. During each scheduled maintenance period.

B. At set periods once the rate of wear has been established.

C. After every repair or modification.

Ans : At set periods once the rate of wear has been established.

Explanation: New components always wear more than when they are run in. SOAP monitoring periods depend on the component not on the aircraft servicing cycle.

49. Starting an engine with a bleed valve stuck closed would cause:.

A. low E.G.T.

B. possible stalling of the engine.

C. high E.G.T.

Ans : possible stalling of the engine.

Explanation: Bleed valves are normally open on start to prevent stalling.

50. Galling is a condition caused by excessive.

A. chafing.

B. scoring.

C. temperatures.

Ans : chafing.

Explanation: See Dale Crane - Dictionary of Aircraft Terms.

51. If a burner was down, in a multi-can system, the engine would tend to.

A. hang up.

B. run up.

C. surge.

Ans : surge.

Explanation: If a combustor tube fails to ignite there will be a pressure build up at the entrance to that burner can.

52. If the rundown time is less than the minimum stated for a given engine.

A. unacceptable wear is occurring at the main bearings.

B. the rotating assembly is free.

C. the rotating assembly is being restricted.

Ans : the rotating assembly is being restricted.

Explanation: Failure to allow the engine to stabilise at idle after high power runs may cause the rotor to rub on the casing in older engines.

53. When running an engine the following lights should be on:.

A. anti-collision and nav-lights (if fitted).

B. nav-lights (if fitted).

C. anti-collision (if fitted).

Ans : anti-collision and nav-lights (if fitted).

Explanation: An anti-collision light is always fitted and turned on for ground running. If there are nav lights it makes sense to have them on as well.

54. With spectral oil analysis program (S.O.A.P), samples are taken.

A. when the oil tank is full.

B. at a specified interval.

C. when the oil is warm.

Ans : at a specified interval.

Explanation: SOAP samples are taken at routine servicing intervals as part of a preventative maintenance system.

55. During start, if a bleed valve is stuck closed.

A. E.G.T is unaffected.

B. E.G.T will be higher than normal.

C. E.G.T will be lower than normal.

Ans : E.G.T will be lower than normal.

Explanation: More air is passing through the engine than it should therefore it will be cooler.

56. Dynamic balance testing locates unbalance in.

A. all planes.

B. two planes.

C. one plane.

Ans : two planes.

Explanation: Dynamic balance is caused when the masses that are rotating are not equal and when the component parts, for example, propeller blades, are not tracking in the same plane.

57. On a gas turbine engine with baked oil deposits, how would you carry out grit blast cleaning With the engine at?.

A. stationary.

B. idle speed (low).

C. high speed.

Ans : idle speed (low).

Explanation: Compressor cleaning is done with the engine running using a variety if grits in a water solution.

58. A rotation pad on an accessory drive gear box is provided for.

A. N2 rotation.

B. both are correct.

C. alternate tachogenerator fitment.

Ans : N2 rotation.

Explanation: The rotation of the H.P compressor is required during borescope inspection.

59. What would be indicative of a hung start?.

A. Starter would fail to disengage.

B. High E.G.T.

C. Engine would fail to reach self sustaining speed.

Ans : Engine would fail to reach self sustaining speed.

Explanation: In a hung start the engine normally stagnates at or near the starter cut out and any attempt to accelerate the engine will result in a hot start.



Click Here For : DGCA & EASA Module 15 : Part-19 Engine Storage, Preservation & Powerplant Installation Question