8 Feb 2014

Paper – III Subject jet engine Question paper Session – JUNE 95





AME Lic. Exam.
 (objective)
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1. Consider forget turbine helicopter engine running at max. gas generator speed any increase of
load will
(a) Reduce NTL only
(b) Both Ng and NTL will increase
(c) Bring down gas generator speed
(d) Increase Ng and decrease ferr turbine speed (NTL)

2. Refer the fig. Of turbine disc/blade and mark correct statement
(a) Teritiary creep is independent of gas temperature
(b) The rate of primary creep is always less than of the secondary creep
(c) The middle portion of the blade is exposed to high temp than root and tip of the blade
(d) All the above are correct

3. When a turbojet engine operating at steady state max RPM any increase of airmass flow due to
inlet variable
(a) May increased the compression ratio
(b) May decrease the compression ratio.
(c) Not affect the compression ratio
(d) None of the above

4. The following fig shows a electrical tube anti icing system of an enging inlet.
(a) Outer surface is continuously heated
(b) Repairing element by welding decreases the element resistance
(c) Forward element is cyclicly heated
(d) There is no over heat protection when the A/C is on the ground

5. The principle involved in controlling the fuel flow according to the requirement of he engine?
(a) Keeping the delta pressure across the metering valve constant and changing the cross section
of the orific
(b) Keeping the constant section of the orific constant and varying the dolta pressure across the
metering valve
(c) Sessing the feed back from RPM and EGT thermocouple and controlling the fuel through
the electronic controller.

6. Hottest section of the engine is
(a) Combuction chamber casing
(b) H.P. turbine casing
(c) L.P turbine causing
(d) Jet pipe casing

7. When CDP sensor fail during cruise condition or high power condition the engine will.
(a) Flame out
(b) Surge
(c) Decelerate to idle condition
(d) Accelerate to max power condition


8. On a twin spool turbofan engine with electronic TGT limitor (Amplifier) all engine paramotors
are fluctuating at max. RPM this is due to malfunction of
(a) Amplifier
(b) TGT thermocouples storm
(c) N1 senser system
(d) Any one of the above

9. Mark the correct statement regarding cracks
(a) A & B can be detected by longitudinal magnetization
(b) B can be detected by either circular or longitudinal magnetization
(c) C can be detected by circular magnesation.
(d) None of the above

10. The advantages of the type of injector shown in the figure is
(a) Fuel regulator not required
(b) Two injectors are used in an engine.
(c) Does not depend on rate of fuel flow
(d) All the above are correct

11. In a typical turboshaft free power turbine engine, the FCU basically senses.
(a) The power lever governor free turbine
(b) The power turbine
(c) The power lever governor free turbine through power turbine
(d) Gas generator

ESSAY - TYPE

1. A modern aircraft fitted with two turbofan engines is O.K during engine ground run performance.
The aircraft was released for flight with instructions to the pilot. During take-off run, there was a
jerk with rise in EGT, severe EPR fluctuation and vibration. The pilot aborted the take-off.
(a) What is the cause and the events took place in a sequance?
(b) What are the critical areas to be checked for the cause and the remedial action.

2. (a) What will happen if the P & D valve is struck in open condition during starting?
 (b) What are the functions of straightening vanes of exhaust cone?
 (c) How the micro organism form in the fuel how they affect the fuel system and its
components? How they are detected?
 (d) What are the areas to be checked for high oil consumption?
(e) What is the trim balancing?

3. How will you check the serviceability of the following
I. LOP switch II. Tacho generator
III. Surge bleed valve IV Oil temp. bulb
V Thermocouple harness VI RPM pulse pick – up

b. Describe the serviceability check of H.E ignition system.

4. In the figure given below
(a) Identify the parts
(b) Explain the purpose of various parts.

a. How will you perform emergency shut down of APU during ground run

b. Where are the boroscopic inspection holes are provided in the engine and how and they helpful in
monitoring the health of engine?
c. What actions you will take during fire warning stall/surge and engine flame out?

5. Titanium should not be cleaned
(a) Trichlor ethylene
(b) Rx 222

6. RD 2490 is
(a) Corrosion inhibitor
(b) Synthetic oil
(c) Cleaning agent
(d) None of the above

7. After shut down of engine the boost pump should never be put off until the engine rotor stop this
make that the
(a) EDP do not loose prime
(b) F & D operate correctly
(c) Fuel pump life more
(d) Fuel filter operation is satisfactory

8. In hydro mechanical fuel control if CIT sense fail on hot day then engine
(a) Takes more time to accelerate
(b) Run at low RPM
(c) Surge and EGT may occur
(d) All the above are correct

9. Crack pressure adjustment of P & D valve is at low side
(a) Secondary fuel flow casier
(b) High EGT starter acceleration
(c) Reduce stall margin
(d) All the above

10. The vibration indicator pick up is mounted in the turbine casing it indication
(a) Turbine vibration only
(b) Turbine and turbine casing vibration
(c) Turbine and compressor vibration
(d) All above

11. The blades of the compressor are twisted. This make blade
(a) More pressure on the blade tip than the root
(b) More pressure on the blade root than the tip
(c) More pressure at the middle portion of the blade
(d) None of the above

12. For the water particle inspection of the fuel the water indicator paste is applied at the bottom of
the sample bottle if the water is present in the fuel
(a) The past will come to from the bottom
(b) The bottom of the bottle will be discoloured
(c) The complete sample will be discoloured
(d) None of the above


13. A turbofan engine produce. A thrust of 9100 lbs, the fuel consumption is 700 Gallon/hr. The
SPC will be
(a) 0.07 lb/lb/hr
(b) 0.5 lb/lb/hr
(c) 0.6 lb/lb/hr.
(d) 0.7 lb/lb/hr.

14. The diagram is of a single hydraulic actuator for satic vanes the is will be
(a) 200 PSI
(b) 20 PSI
(c) 10 PSI
(d) 200 PSI

15. Compressor blades are not fitted rigidly on the nut there is a slight movement this is done to
(a) Provide case of replacement of blade
(b) To provide relief for the expansion of the blade due to heat
(c) To reduce vibrational stress on the blade
(d) All the above

14. The baffles plates are incorporated in the oil tank the of this plate is
(a) To avoid local turbulence and recirculation of used of
(b) To settle down the foreign particles in the bottom
(c) They give cooling capacity
(d) All the above are correct

15. For soap analysis the sample must be collected
(a) Within ½ an hour of the engine shutdown
(b) After enough cooling of the engine
(c) After half an hour of the engine showdown
(d) Any time

16. For a given EPR if the OAT decreases the N2 RPM of turbofan engine will
(a) Increase
(b) Decreases
(c) Remain same
(d) Increases N2 with decrease of EGT

17. If engine fitted with hydro mechanical FCU when speed sense N2 fails during IDLE condition
the engine.
(a) Flame out
(b) Can not accelerate above IDLE RPM
(c) Accelerate to high power bottj
(d) None of the above

18. Match the following
(a) Threaded (a) Air intake
(b) Un threaded (b) Fuel lines
(c) Greased blank (c) Compressor of take
(d) Grease proof paper (d) Rubber part

19. Match the following
(a) Injector wheel (a) Simplex

(b) Secondary burner (b) Centrifugal
(c) Double cone (c) Duplex
(d) A square low injector (d) Pre vaporization form.

20. Match the following
Differential pr. Aerodynamic Angle of incidence Pressure acro
On vane produces force produces &Subsequent stage Vane
(a) Torque load pending move- Reduces increases
 ment
(b) Bending move- Torque load. Increases increases
 ment
(c) Bending move-
 Ment Torque load increases constant
(d) Torque load. Bending load. Increases Reduced


21. Match the following
 starting control study state control acceleration decreases
(a) Droop cam 3D cam Droop cam 3D cam
(b) 3D cam 3D cam 3D cam Droop cam
(c) 3D cam 3D cam Droop cam Droop cam
(d) droop cam Droop cam 3D cam 3D cam

22. Match the following
(a) Blade rotainor (a) In assembly stiffness
(b) Spacer (b) Radial movement
(c) Spinner road cone (c) Axial movement
(d) mid span shroud (d) Axial stability on rotation

23. Match the following
structural most efficiency easy inspection For lower no
stability emmision
(a) Can annular annular Can annular Double annul
(b)

24. If the spring prossure of the P & D valve is weak each
(a) The engine will run at lower RPM
(b) The engine will run at higher RPM
(c) Higher EGT
(d) All the above

25. The transformation of kinetic energy in to pressure energy is NIL in which type of engine
(a) Turbo prop
(b) Turbo jet
(c) Turbo shaft
(d) By passed fan

26. Bell mouth compressor is used in engine calibration on ground because
(a) The duct loss is so small that it is considered zero and the engine performance date can be
gathered without any correction for inlet duct loss being necessary

27. The purpose of slot in the fig. Of impeller

(a) Used for balancing
(b) Ease of fitting in the zig and fixture during manufacturing
(c) Surge protection
(d) All the above are correct

28. In fig. The area of the compressor casing the gradually decreasing if it is constant
(a) Velocity decreased
(b) Velocity in even

29. Match the following
(a) EGT (a) D.C. pulse
(b) Acceleration (b) EMF
(c) Oil pr. Transducer (c) Charge
(d) Fuel flow transducer (d) Reluctance

30. In the Fig of ignition system R is
(a) A co
(b) Filter
(c) Vibrator
(d) To producer India interference

31. In case of post exit thrust reverser
(a) Down lock pressure is less than the reflecting pressure
(b) Down lock pressure is more than the deflecting pressure

32. In the APU of the A/C holes are provided near the exhaust the pu is to
(a) Exhaust duct air intake cooling oil breather
(b) For cooling
(c) Exhaust of QPU

33. In the secematic of the fuel filter
(a) A is the inlet
(b) B is the inlet
(c) C is the inlet
(d) Either A or B is inlet

34. The figure indicates
(a) Compressor
(b) Turbine
(c) Fan
(d) Can not be indentified

35. In the efficiency graph shown A, B, C, D stand for
 A B C D
(a) Turbo prop Lowby pass high by pass turbo jet
(b) Low by pass turbo prop turbo jet high by pass


36. In the filter system if both the filters are clogged the pressure at A will be
(a) 10 PSI
(b) 60 PSI
(c) 30 PSI

(d) 20 PSI

37. In given diagram A is
(a) Flame holder
(b) Flame stabilizer