| True-False
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| 1. |
The power turbine extracts velocity energy from the hot gases and transmits mechanical power to the output shaft.
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| 2. |
In figure 5.5, station No. 4 is located from the beginning of the centrifugal compressor to the air diffuser.
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| 3. |
A 3.75-gallon oil tank is contained in the inner housing of the inlet housing assembly.
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| 4. |
The L-11 model has a two-stage gas producing turbine.
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| 5. |
The right and left sides of the engine are determined by looking at the engine from the front.
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Cluster True-False
Each of the following groups of questions is related to the statement that precedes them.
FIRST GROUP
The T55-L-11 engine fuel system includes:
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| 6. |
Fourteen vaporizing tubes instead of 28 dual atomizing nozzles.
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| 7. |
A fuel control unit is made up of the flow control and computer sections.
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| 8. |
Actuation of the compressor bleed band by the fuel control section.
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| 9. |
A cooler that uses fuel to cool engine oil.
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| 10. |
Main and start fuel manifolds at the rear of the combustion chamber assembly.
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SECOND GROUP
Which of the following statements about the sections of the T55-L-11 are true and which false?
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| 11. |
The compressor has a seven-stage axial compressor.
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| 12. |
The divergent shape of the diffuser decreases air pressure and increases velocity.
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| 13. |
The struts between the inner and outer air inlet housing are hollow, with passages for oil and accessory drive shafts.
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| 14. |
The combustor has 14 fuel nozzles in each one of its two main fuel manifolds.
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| 15. |
A variable inlet guide vane assembly is mounted in the front of the compressor housing.
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THIRD GROUP
The following statements are about various systems in the T55-L-11 engine. Evaluate them by marking them true or false.
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| 16. |
The anti-icing system for the variable inlet guide vanes uses hot scavenge oil.
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| 17. |
Bearing seals are pressurized by some of the cooling air.
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| 18. |
The purpose of an interstage air bleed system is to avoid compressor stalls and to increase compressor rotor acceleration.
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| 19. |
The control system for the variable inlet guide vanes schedules their positions according to gas producer speed and compressor inlet temperature.
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| 20. |
Several passages throughout the engine receive air from the main airflow to cool components.
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| 21. |
The torquemeter system gives a reading in the cockpit of percent of torque.
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FOURTH GROUP
The lubrication system in the T55 engine has the following characteristics. |
| 22. |
All oil filters can be changed at intermediate level maintenance.
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| 23. |
The low-level warning switch in the cockpit signals when a 2-hour supply of usable oil remains.
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| 24. |
After oil leaves the main oil pump, it goes through a filter in the accessory gearbox.
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| 25. |
Chip detectors activate caution lights in the cockpit.
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| 26. |
The main oil pump is used entirely to maintain pressure in the oil system.
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| 27. |
The entire lubrication system is contained in the engine.
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FIFTH GROUP
Which of the following statements describe the T55 gas turbine engine? |
| 28. |
The accessory drive section is part of the annular flow path.
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| 29. |
The speed of the power output shaft is the same as that of the power turbine.
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| 30. |
The airflow is reversed twice in the combustor section.
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| 31. |
In the combustor, the curl assembly reverses the airflow direction for the first time.
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| 32. |
The swirl cups in the combustor contain dual-orifice, fuel-atomizing nozzles.
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| 33. |
The T55 engine has six sections.
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SIXTH GROUP
In comparing the different models of the T55, you find that: |
| 34. |
The normal shp for the L-11 is the same as the military shp for the L-7C.
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| 35. |
The L-7's all have 28 dual-orifice fuel spray nozzles.
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| 36. |
The L-7B has the most accurate electric torquemeter.
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| 37. |
The L-11 model has a two-stage GP turbine.
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| 38. |
All models of the T55 have the same shaft horsepower.
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| 39. |
The CH-47C cannot use the T55-L-11 engine.
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