TH-67 Systems Study Guide

TH-67 Systems Study Guide
(General Description, Flight Controls and Hydraulics, Rotors, and Power Plant)

1. Define the term WARNING
An operating procedure, practice, etc., which if not strictly observed could result in damage to or destruction of equipment. A mandatory procedure An operating procedure, practice, etc., which if not correctly followed could result in personal injury or loss of life. Indicated futurity

2. Define the term CAUTION
An operating procedure, condition, etc., which is essential to highlight. An operating procedure, practice, etc., which if not strictly observed could result in damage to or destruction of equipment. An operating procedure, practice, etc., which if not correctly followed could result in personal injury or loss of life. Indicates futurity

3. Define NOTE A mandatory procedure
Recommended or preferred, not mandatory. Indicates futurity An operating procedure, condition, etc., which is essential to highlight.

4. Define the term SHALL Indicated futurity A mandatory procedure
An optional procedure Recommended or preferred, not mandatory

5. Define the term SHOULD Recommended or preferred, not mandatory
An optional procedure A mandatory procedure An operating procedure, condition, etc., which is essential to highlight

6. Define the terms MAY or NEED NOT
Indicated futurity A mandatory procedure A condition that you may do or not An optional procedure

7. Define the term WILL An optional procedure Indicates futurity
A mandatory procedure A procedure that will be done

8. The three sections of the TH-67 fuselage are the _____, _______, and the _______ section.
cockpit, cabin, and aft boom front, intermediate, and back tail forward, intermediate, and tail boom cockpit, cabin, and tail

9. The VFR & A+ configuration have one pitot that provides _______ air to the airspeed indicator and two vents that provide _____ air to the static instruments. direct, indirect pressure, kinetic impact (ram), static direct, static

10. The IFR configuration has __ ______ pitot/static systems.
4 separate 3 individual 2 independent 2 individual

11. The TH-67 ____ light, located on the aircraft nose provides a 450 watt lamp in an extendable and slewable mount. landing position collision search

12. The TH-67 ____ light, located on the aircraft nose provides a 250 watt lamp in a fixed mount.
landing search position collision

13. How many switches are used to control the search light in the NVG mode on the A+ configuration?
2, one for selecting IR light, and one to turn it on. 4, one to turn it on, one to select white light, one to select IR light, and one to slew the search light to extended and retracted position. 3, one to select the IR light, one to turn the light on, and one to slew the search light to the desired position. 2, one on/off switch, and one to select IR.

14. What does the term semi-monocoque mean?
The skin of the aircraft provides all of the structural strength The aircraft skin provides none of the structural strength The aircraft skin provides some of the structural strength None of the above

15. The TH-67 intermediate section uses a ____ type of construction.
semi-rigid semi-flex semi-monocoque monocoque

16. Which section of the aircraft contains the engine?
A. The forward section B. The cabin section C. The engine/transmission section D. The intermediate section

17. The TH-67 tail boom section uses ___ ______ type of construction.
semi monocoque partial monocoque fully monocoque semi rigid

18. State the purpose of the vertical fin.
Provides vertical stability on the x-axis The vertical fin, being displaced (canted) 5 ½ degrees to the right thus reducing the tail rotor thrust requirements in forward flight Off-loads the tail rotor between 80 and 100 knots Provides vertical stability on the yaw axis

State the purpose of the horizontal stabilizer.
A. Maintains a desirable aircraft attitude through the high end of the airspeed range. The metal strip at its leading edge provides for autorotational stability. B. Provides pitch (up and down) about the lateral axis C. Provides horizontal control of the aircraft during low “G” maneuvers. D. None of the above

19. At what airspeed is the tail rotor fully off-loaded in forward flight?
Between 110 and 130 knots Between 90 and 120 knots At 100 knots Between 100 and 110 knots

20. The nomenclature of the TH-67 power plant is the model _______.
T700-GE-401C JP-WD40 PW-123-J 250-C20J

21. State the maximum torque available (MAX TQ AVAIL).
107% TQ for 15 seconds max 100% TQ for 5 minutes max >85% to 100% for 5 minutes max 100% TQ for 5 seconds max

22. State the maximum continuous power (TQ AVAIL CONT) of the TH-67 power plant.
85% TQ (270 SHP) no time limit 85% TQ (270 SHP) take-off power range 5 minute limit >85% to 100% TQ maximum 100% TQ no time limit

23. Can the maximum transient power setting (110% TQ) be used intentionally?
Yes, 5 minutes limit Yes, 5 seconds limit No, only when executing high ‘G’ maneuvers No, intentional use is prohibited

24. State the diameter of the TH-67 main rotor.
52’ 4” 42’ 4” 33’ 4” 44’ 3”

25. What type of airfoil is the main rotor blade?
A honey comb airfoil A symmetrical airfoil An asymmetrical airfoil None of the above

26. How many degrees of twist are there in the main rotor blade?
A positive 10 degrees A negative 5 degrees A positive 5 degrees A negative 10 degrees

27. State the tail rotor diameter.
5’ 10” 4’ 5” 5’ 5” 8’ 5”

28. How many degrees of pitch are in the tail rotor with full left pedals applied?

29. State the TH-67 Vne 122 knots 78 knots 130 knots 100 knots

29. State the maximum airspeed limitation with >85 to 100% TQ applied.
78 knots 110 knots 80 knots 122 knots

31. State the minimum rate of descent airspeed in autorotation.
A RPM (100% rotor RPM) B RPM (100% rotor RPM) C RPM (100% rotor RPM) D RPM (100% rotor RPM)

32. State the maximum glide distance airspeed in autorotation.
RPM (100% rotor RPM) RPM (100% rotor RPM) RPM (100% rotor RPM) RPM (100% rotor RPM)

33. State the minimum crew restriction VFR and IFR.
VFR minimum 1 pilot, IFR minimum 1 pilot and 1 observer VFR minimum 2 pilots, IFR minimum 1 pilot VFR minimum 1 pilot, IFR minimum 2 pilots VFR minimum 1 student, IFR minimum 1 student and 1 pilot

34. State the fuel capacity of the TH-67 fuel cell.
69.4 U.S. gallons total; 64.2 U.S. gallons useable; 2.3 U.S. gallons unusable 81.4 U.S. gallons total; 64.2 U.S. gallons useable; 1.5 U.S. gallons unusable 69.4 U.S. gallons total; 68.2 U.S. gallons useable; 1.3 U.S. gallons unusable 84.1 U.S. gallons total; 82.6 U.S. gallons useable; 1.5 U.S. gallons unusable

35. Why must the engine oil system be drained and refilled if transmission and engine oils are intermixed? To prevent chemical reaction To prevent damage to the engine oil seals If the two are mixed they become very flammable To prevent damage to the transmission

36. In a conventional helicopter, what are the three basic flight controls that are used to maneuver the aircraft? Throttle, stick, rudder Cyclic, stick, collective Cyclic, collective, tail rotor (anti-torque) pedals Stick, elevator, vertical fin

37. In a conventional helicopter, which flight control directs the total lift/thrust of the main rotor system? The collective The stick The pedals The cyclic

38. Which conventional helicopter flight control will input a pitch change to all main rotor blades simultaneously regardless of the blades position? Cyclic Rudder Collective Stick

39. In a conventional helicopter, the rotation of the main rotor induces a force known as torque. Describe the effects this force has on the fuselage. The torque force will cause the fuselage of the aircraft to rotate in the same direction of the main rotor The torque force will cause the fuselage of the aircraft to rotate in the opposite direction of the main rotor No effect is observed since rotor torque and fuselage torque will be equalized None of the above

40. State the primary purpose of the tail rotor system in a conventional helicopter.
Provides directional control Yaws the aircraft To counter-act the torque effects of the main rotor Provides right and left inputs on a hover

41. The ___ ____ controls will provide directional control (heading) of the aircraft during hovering, as well as trimming the fuselage of the helicopter at higher speeds. Cyclic pedals Stick pedals Tail rotor A and B

42. Cyclic control inputs (fore/aft and lateral) are considered independent up to the _____ ______ from there on up to the non-rotating swash plate they are considered ______. intermixing bellcrank, coordinated self adjusting controls, manual intermixing push rods, coordinated self input controls, manual

43. In the VFR configuration, what happens to the pilot’s cyclic stick if left unattended when the copilot’s cyclic stick is removed? Nothing, there is no difference with both or just one cyclic stick installed/removed The reduced load on the balance spring will cause the pilot’s cyclic stick to creep aft slightly If this situation is encountered you must not go flying do to lack of controls on the aircraft You must maintain right cyclic input to counteract for the missing copilot’s cyclic stick

44. Where is the cyclic friction knob located?
Right on the base of the copilot’s cyclic stick There is not such thing installed in the TH-67 helicopter In between the pilot and copilot seat Left of the base on the pilot’s cyclic stick

45. How much preload is on the cyclic system with the aircraft running and the hydraulics on?
2 to 3 pounds preload 1 to 1 ½ pounds preload 2 ½ to 4 pounds preload ½ to 1 pound preload

46. Which aircraft configuration has the force trim system?
VFR only IFR only A+ only All of the above

47. What switches are located on the pilot’s collective stick control head?
On/off switch, landing light, fuel start Search light switches, landing light, governor RPM increase/decrease, and the starter button There is no switches on the pilot’s collective stick; all switches are located on the copilot’s collective stick Fuel valve switch, landing light, starter button, and hover button

48. Where is the collective friction located?
It is located on the right of the copilot’s collective stick base Right behind the pilot’s anti-torque pedals It is located on the left of the pilot’s collective stick base No such thing installed in the TH-67 helicopter

49. What switches are located on the co-pilot’s collective control head?
The search light switch, landing light, governor RPM increase/decrease, and the starter button Fuel valve switch, throttle switch, landing light, and hover switch There is no c0-pilot collective control head Eject switch, landing light, fuel valve switch, and avionics

50. What amount of collective control preload is built into the collective flight control system?
2 to 4 pound preload 1 to 3 pound preload 4 to 6 pound preload 3 to 5 pound preload

51. Which collective control stick is removable and why?
The co-pilot‘s collective stick is removable in case a non-rated passenger is flown in the co-pilot’s seat The pilot’s collective for egress purposes Neither the pilot or co-pilot’s collective stick can be removed unless is for maintenance reasons only None of the above

52. Which direction can the tail rotor pedals be adjusted?
Forward only Aft only Pedals are fixed and can not be re-adjusted The pedals can be adjusted fore and aft

53. What changes the pitch (angle-of-attack) in the tail rotor through the lever assembly?
The pitch horn The tail rotor bell cranks The pitch change links The anti-torque pedals

54. What is the preload on the tail rotor system?
1 to 3 pounds preload 3 to 5 pounds preload 2 to 5 pounds preload 4 to 5 pounds preload

55. Does the tail rotor system have hydraulic assist?
The tail rotor system does not have hydraulics Yes Yes, but only in the retreating blade to prevent tail vibrations None of the above

56. The TH-67 flight control system can best be described as ____ ____ ____ with hydraulic assist.
fully articulated links hydro mechanical linkages direct mechanical linkages articulated mechanical links

57. The purpose of the hydraulic servo actuator installed to the cyclic and collective controls is to convert ____ ____ under pressure into ____ ____ work. JP-8 fuel, carbon monoxide hydraulic fluid, useful mechanical servo fluid, useful mechanical Hydraulic fluid, control movement

58. The TH-67 hydraulic pump is a constant ____, _____ delivery system component providing 600 +/- 25 psi, and _____ GPM flow rate. pressure, variable, 1.9 flow, direct, 2.3 pressure, flow, 1.2 flow, pressure, 1.9

59. The purpose of the differential release valve is to reduce ____ ____ ____ when rotor loads are increased due to high “G” maneuvers or flight into turbulence. rotor centrifugal forces transmission high speeds engine high speeds pressure build up

60. With regard to cyclic input, does the blades position in the plane of rotation matter?
No Only during forward flight Yes, the desired input does not occur until the blade is positioned exactly 90º earlier in the plane of rotation (phase lag) Only during right side flight above 20 knots

61. What drives the rotating swash plate?
The transmission The power turbine The connection of the collar set and idler lever/link assembly to the rotating swash plate The rotating scissors

62. What is another name for the collar set and idler lever/link assembly?
The drag link assembly The rotating link assembly The rotating swash plate link None of the above

63. What connects the rotating swash plate to the pitch change horn?
The pitch control rods (PCR) The pitch change tubes The swash plate tubes The pitch horn tubes

64. What type of rotor system is used on the TH-67 helicopter?
Fully articulated rotor system Fully aerobatic rotor system Rigid, semi-articulated rotor system Semi-rigid, under slung rotor system

65. How is the rotor system attached to the mast?
It is attached to the mast by 4 grade 1172 steel bolts The rotor system is attached to the mast by means of bolts, washer, and nuts The rotor system is attached to the mast by a splined trunnion None of the above

66. What is the definition of a trunnion?
A component that holds things together The act of bringing two objects of dissimilar shapes to form one A component that allows rotation and tilt To turn or to be turned

67. What is the purpose of the yoke?
Attaches the main rotor and main transmission to the hub To support the main rotor system and serves as the pitch change axis Sends a signal to the cockpit to let the pilot know of exact angle of pitch in the main rotor blades A and C

68. How is the trunnion attached to the yoke?
The trunnion is attached to the yoke by pillow blocks The trunnion is attached to the yoke by 2 high impact type 117 grade steel bolts The trunnion is attached to the yoke by the go/no-go fly wheel assembly The trunnion does not attached to the yoke by any means. They are two separate systems independent of one another

69. What kind of balancing requires lead weights to be added to the blade retention bolt?
Trailing edge balancing requires lead weights to be added to the blade retention bolts Sprout rigging balancing requires lead weights to be added to the blade retention bolts WARNING. Never add weights to the blade retention bolts Spanwise (root to tip) balancing requires lead weights to be added to the blade retention bolts

70. What distributes the centrifugal load from the blade grip to the yoke?
The under-slung design of the TH-67 rotor system The yoke centrifugal bearings Tension torsion straps The is no centrifugal force load from the blade grip to the yoke

71. What structural members make up the main rotor blade?
The titanium spar, the chamber, and the trailing edge The aluminum spar, the spar closure, and the trailing edge The titanium spar, the spar closure, and the trailing edge Aluminum, honey comb, and titanium

72. Weights are added at the factory at the time of manufacturing to control the undesirable twisting associated with asymmetrical airfoils and to preserve favorable aerodynamic characteristics. True False

73. Why does the main rotor blades have a negative 10º twist?
The negative twist is designed to equalize lift during autorotation The negative twist is designed to prevent turbulence during high power/high “G” maneuvers There is no negative twist on the main rotor blades The negative twist is designed to equalize lift along the blade span (length)

74. The “droop snoot” is known for what aerodynamic characteristics?
The “droop snoot” design is noted for a wide thrust margin for maneuverability and high efficiency during forward flight The “droop snoot” design is noted for a wide thrust margin for maneuverability and high efficiency during hovering The “droop snoot” design is noted for a wide thrust margin for maneuverability and high efficiency during turns The “droop snoot” design is noted for a wide thrust margin for maneuverability and high efficiency during autorotation

75. How many trim tabs are there on the main rotor blade?
Two trim-tabs, one for adjusting A+ vibrations and the other one to adjust B+ vibrations Just one trim-tab Three trim-tabs, one for adjusting the inner blade track, a second for the middle blade track, and a third for the outer blade track Two trim-tabs, one for adjusting the inner blade track, and a second trim-tab is used to adjust the outer portion of the blade’s track

76. What are doublers used for on the main rotor blade?
They are applied at the blades root to sustain the shearing force caused by the centrifugal force occurring at the blade retention bolt Used to equalize lift along the blade span (length) They are designed to stop excessive droop (lower motion of the blade) and conning (upper movement of the blade) Doublers are used on the main rotor to reduce main rotor vibrations during slow autorotations

77. What is the purpose of the flap restraint kit?
Its purpose is to limit flapping during autorotations Its purpose is to limit flapping during high power maneuvers Its purpose is to limit flapping during startup and shutdown The is no flap restraint system installed on any under-slung rotor system

78. At what RPM is flapping limited to 6º maximum?
At 90% N2 and below At 97% N2 and below At 25% N2 and below At 31% N2 and below

79. At what RPM is the flapping angle no longer limited?
Above 31% N2 RPM Above 85% N2 RPM Above 90% N2 RPM Above 25% N2 RPM

80. How is the tail rotor assembly mounted to the tail rotor output shaft?
It is mounted to the tail rotor output shaft by a quick disconnect fitting It is mounted to the tail rotor output shaft by a splined trunnion It is mounted to the tail rotor output shaft by two crossheads bolts It is mounted to the tail rotor output shaft by a spherical bearing

81. How does the tail rotor system compensates for dissymmetry of lift?
The tail rotor assembly compensates for dissymmetry of lift through the chordwise hinge by allowing the blade to feather as it flaps The tail rotor assembly compensates for dissymmetry of lift through the trunnion hinge by allowing the blade to feather as it flaps The tail rotor assembly compensates for dissymmetry of lift through the crosshead hinge by allowing the blade to feather as it flaps The tail rotor assembly compensates for dissymmetry of lift through the delta hinge by allowing the blade to feather as it flaps

82. What are the washers on the blade bolts used for?
They are used for preventing corrosion from dissimilar metals They are used for counter weight They are used for spanwise balancing None of the above

83. What are the rectangular weights and washers on one end of the trunnion used for?
They are used for chordwise balance They are used for spanwise balance They are used for trailing edge balance They are used for leading edge balance

84. What are the nut, bolt, and washer(s) used for on the dynamic balance wheel?
They are used to eliminate high frequency vibrations and to assist in spherical and chordwise balance They are used to eliminate high frequency vibrations and to assist in spanwise and trailing edge balance They are used to eliminate high frequency vibrations and to assist in spanwise and chordwise balance None of the above

85. Where are the weights that are added at the factory located?
They are located on the outboard trailing edge and the blade tip They are located on the inboard trailing edge and the leading edge They are located on the inboard trailing edge and at the blade tip None of the above

86. What are the washers on the pitch horns used for?
They are used as aerodynamic balance during steep turns/high “G” maneuvers There are no washers installed on the pitch horn They are used as aerodynamic balance to eliminate “pedal creep” They are used for spanwise balancing

87. The TH-67 engine’s rated shaft horsepower is de-rated for _____ ______.
100% TQ 85% TQ Transmission compatibility Turbine comapatibility

88. The statement that best describes the TH-67 engine is “Internal combustion gas turbine featuring a ______ ______ ______. free gas turbine free power turbine reverse combustion chamber compressor discharge tube

89. What are two advantages of a free turbine?
Reduces cost throughout the Army, and since is free it does not require calibration every 1,000 hours of flight Provides reduced load for starting , and each turbine operates at optimum RPM capacity No mechanical connection between the gas turbine thus reducing friction and loss of power, and they can be operated independently of each other No cost to the Army, and they are light weight

90. The purpose of the Air Barrier Filter is to provide clean ______ air to the engine.
particle-free fresh cool All of the above

91. Will the engine air be filtered if the ENG ALT AIR switch is placed in the open position?
Yes, but only 39% of the air passing through will be filtered No such switch installed in the TH-67 helicopter Yes, when the air filtered is bypass, filtered air will still be going into the engine through the secondary filtration system No, when the air barrier filter is bypass, unfiltered air will be going into the engine

92. What indication will the pilot receive when the air barrier filter is blocked/clogged?
The FILTER CLOGGED caution light will illuminate The HIGH INLET PRESSURE caution light will illuminate The LOW INLET PRESSURE caution light will illuminate There is no indication sent to the cockpit for this condition

93. What are the four sections of the model 250-C20J turbine engine?
Intake, compressor, combustion, and exhaust section Power turbine, combustion chamber, exhaust, and ignition section The compressor, power and accessory gearbox, turbine, and combustion section The stator vanes, the rotating vanes, the centrifugal stage, and the impeller section

94. What does the bleed air control valve do?
It aids in rapid engine acceleration and helps prevent compressor stalls It controls the amount of bleed air needed for cabin/cockpit heating It controls bleed air for de-icing of the compressor inlet vane Both B and C

95. What are the five customer bleed air ports on the diffuser scroll?
Anti-icing, vent and cap, discharge air, exhaust holes, and PC filter The engine anti-ice valve, bleed air control valve, two cabin heat ports, and PC air filter Two cabin heat ports, cockpit heat port, and the PC air filter None of the above

96. What is the purpose of the cap on the rear diffuser vent and cap?
To increase air pressure on one side of two labyrinth seals as the compressor experiences wear. To equalize the high pressure between the diffuser and the compressor section To prevent Foreign Object Damage (FOD) from entering the diffuser Vents out high pressure from the diffuser and redirects it to the compressor

97. The compressor consists of how many and what kind of compressor stages?
It consists of four axial stages and one centrifugal stage It consists of five axial stages and two centrifugal stage It consists of five axial stages and one centrifugal stage It consists of six axial stages and one centrifugal stage

98. On a standard day the airs temperature increases to approximately ___ ºF by the time it goes through the seventh stage of compression. 1270 456 502 520

99. What are the only items provided with anti-icing capability?
The engine inlet, and the windshield The windshield, and the main rotor blade leading edge Both, main and tail rotor blades leading edges The front support hub and the seven inlet guide vanes

100. Should the bleed-air control valve be opened or closed on preflight?
The bleed-air control valve SHALL be closed on preflight or maintenance action is required This valve can not be seen unless parts from the engine are removed during major overhaul to the engine The bleed-air valve SHOULD be closed on preflight or maintenance action is required The bleed-air valve SHALL be open on preflight or maintenance action is required

101. When does the spark cease to exist in the combustion section of the engine?
When N1 reaches 90% RPM When N2 reaches 90% When the starter button is released The spark never ceases unless there is a failure of the exciter box or engine tachometer generator

102. What is the temperature of the flame in the combustion section of the engine?
Approximately 4500 ºF Approximately 5500 ºF Approximately 3500 ºF Approximately 2500 ºF

103. What is the melting point of titanium?

104. How much of the compressed air is used for combustion?
Approximately 20 to 25% Approximately 50 to 60% Approximately 70 to 80% Approximately 80 to 95%

105. T or F Approximately 75 to 80% of the air is used to cool and center the combustion flame plus drive the five customer bleed-air accessories. False True

106. What principle takes advantage of impact and reaction forces?
Newton’s third law of action and reaction Newton’s first law of inertia The gas turbine principle The action reaction principle

107. Changes in ____ ______ cause changes in fuel flow.
power settings wind conditions pressure altitude high temperature

108. Changes in fuel flow will cause changes in _______ of the gases entering the turbine rotors.
cooling temperature expansion

109. Combustion gases impact the gas producer and the turbine rotors inducing _____________________.
rotation of the compressor rotation of the accessory gearbox rotation of the free wheeling unit rotation of the turbine shaft

110. An increase in expansion rate/velocity induces an increase in _____ that is transmitted through the N2 gear train as measurable _______. air, RPM torque, horsepower fuel, shaft torque fuel, horsepower

111. Which section of the engine is the primary structural member of the engine?
The power and accessory gearbox section The compressor section The combustion section The power turbine section

112. What is designed to reduce the high RPM required for horsepower development to more practical RPM at the accessory output pads? The reverse flow combustion chamber Electrical motors dedicated just to the accessory output pads Two separate gear trains (N1 and N2) The N1 tachometer and the N2 tachometer

113. Which section of the engine is driven by the gas producer gear train?
The oil cooler section is the only section driven by the N1 gear train The combustion section is the only section driven by the N1 gear train The turbine section is the only section driven by the N1 gear train The compressor section is the only section driven by the N1 gear train

114. The fuel pump, gas producer fuel control, starter/generator, oil pump, tachometer generator, and the standby generator (only on the IFR configuration) are driven by what gear train? N2 gear train N1 gear train Both, N1 and N2 gear trains None of the above

115. The freewheeling unit, the torque meter, the governor, and the tachometer generator are driven by what gear train? N1 gear train N2 gear train Both, N1 and N2 gear trains None of the above

116. The N1 and N2 tachometer generators produce what kind of voltage?
Direct Current (DC) voltage Alternate Current (AC) voltage The N1 DC voltage, and the N2 AC voltage The N1 AC voltage, and the N2 DC voltage

117. The starter portion of the starter/generator is used to “crank” the ____ _____ _____ during the start sequence. N2 gear train engine combustion section N1 gear train accessory gear box

118. The generator portion of the starter/generator provides ____ ____ voltage to all of the helicopter’s electrical systems plus it re-charges the ___ _____. alternate current, main battery direct current, standby battery direct current, main battery alternate current, standby battery

119. How are the gas producer fuel control and the governor integrated?
They are integrated by pneumatic connections They are integrated by mechanical connection They are integrated by hydro mechanical connections They are integrated electrically

120. What is the purpose of the burner drain valve?
To burn fuel that remains on the outer combustion case To drain unburned fuel from the combustion chamber back to the fuel tank To allow unburned fuel to drain from the outer combustion case None of the above

121. The purpose of the dual accumulator-double check valve is to ____ _____ ______ from the main rotor system. reduce the vibrations dampen torsional vibrations maintain CG balance None of the above

122. Where is the combustions gas temperature measured on the C20-J turbine engine?
Right before the N1 rotor Right after the gas passes by the N2 rotor Right in between the N1 and the N2 rotors A and B

123. Where is the engine oil temperature measured?
At the combustion chamber #7 bearing solenoid It is measured as the oil leaves the bottom of the engine oil reservoir It is measured by a “wet” line (direct oil pressure) By a “wet” line (direct pressure reading)

124. How is the engine oil pressure measured?
It is measured in PSI by a “dry” line It is measured in PSI by the transmission pressure gauge It is measured by a “wet” line (direct oil pressure) It is measured as it passes through the #2 and #7 bearing

125. How is the engine torque measured?
By a “wet” line (direct pressure reading) By the difference in pressure from the sump and the pump It is measured by a “wet” line (direct oil pressure) None of the above

126. Which engine bearings are externally lubricated?
Bearings 1, 2, 5, and 8 Bearings 5, 6, 7, and 8 Bearings 2, 2 ½, 6, 7, and 8 Bearings 1, 6, 7, and 8

127. How many engine oil chip detectors will activate the ENG Chip caution light?
One (the accessory section chip detector) One (the temp/chip detector) Two ( the #1 and #2 chip detectors) Two (the sump and the pump chip detectors)

128. The auxiliary oil filter has a “pop-up” feature that activates at __ PSID.
17 10 7 40

129. After completing lubrication, oil is scavenged into a sump below the number __ and __ bearings and at the bottom of the gear case. 2, 2 ½ 3, 4 5, 6 6, 7

130. How many engine oil bypasses are there?
There are 4 bypasses. Auxiliary oil filter (10 PSID), oil cooler (thermal bypass below 81º C or 178º F), oil cooler (40 PSI clogged oil cooler), and internal oil filter (150 PSID) There are 4 bypasses. Auxiliary oil filter (7 PSID), oil cooler (thermal bypass below 81º C or 178º F), oil cooler (40 PSI clogged oil cooler), and internal oil filter (105 PSID) There are 4 bypasses. Auxiliary oil filter (10 PSID), oil cooler (thermal bypass below 81º C or 178º F), oil cooler (40 PSI clogged oil cooler), and internal oil filter (105 PSID) There are 4 bypasses. Auxiliary oil filter (10 PSID), oil cooler (thermal bypass below 81º F), oil cooler (40 PSI clogged oil cooler), and internal oil filter (105 PSID)

131. How many “wet” lines are there associated with the engine oil system?
Three (the engine oil pressure, and torque meter gauges, and the transmission oil pressure gauge) Two (the engine oil pressure, and the transmission oil pressure gauge) Two (the engine oil pressure, and the torque meter gauges) Three ( transmission oil and pressure gauges, and the torque meter gauge)

132. Is defined as a decrease in N2 RPM that exists between the time a demand for power is made and the time that power is delivered? Spike knock Mast bumping Droop Flapping stop

133. Is droop allowed to exist?
No, INTENTIONAL USE IS PROHIBITED Yes, 5 minute limit Only momentarily, otherwise rotor RPM may become critically low Yes, but rotor RPM must be at 107% RPM to compensate for droop

134. How is droop compensated for?
By lowering the collective, and turning the engine anti-ice and heater switches off Once droop is encounter you must wait until the aircraft recovers from it Through mechanical linkages (collective stick to governor lever), electrical connections (governor increase/decrease switch and linear actuator motor), and a pneumatic signal between the N2 governor and the gas producer fuel control passing through the dual accumulators and double check valve By lowering the collective and maintaining 107% max RPM

135. Why is the engine mounted horizontally behind the transmission
To simplify the drive system, improve the air intake/exhaust arrangement, and to reduce cabin noise All helicopter must have the engine horizontally mounted for weight and balance purposes By the engine being mounted horizontally it will improve the autorotational capability by 40% For no particular reason, it’s just the way the engineers wanted it mounted

136. How are three bipod mounts used to secure the engine?
Semi-rigid Flexible for vibration reduction Rigidly None of the above

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