NATOPS Question Bank
Source: NAVAIR 01-H57BC-1 (15 October 2006)
Question and Answer / Page /1. / The NATOPS manual is issued by the authority of the Chief of Naval Operations. It is your responsibility to have a complete knowledge of its contents. / 39
2. / “May” and “need not” have been used only when application of a procedure is optional. / 41
3. / The primary purpose of the TH-57B is helicopter familiarization training and basic VFR tactical maneuvering. / 1-1
4. / The tailboom is a full monocoque structure, providing maximum strength-to-weight ratio and rigidity. / 1-1
5. / The helicopter is powered by a 250-C20J engine that weighs 157 pounds and is capable of developing 420 shp, but is limited to 317 shp because of drive train limitations. / 2-1
6. / Approximately 75 percent of the air going to the combustion chamber is used for cooling. / 2-1
7. / The gas-producer drivetrain powers the:
a. Gas-producer fuel control
b. Gas-producer tachometer-generator
c. Starter-generator
d. Engine-driven fuel pump
e. Engine oil pump
f. Standby generator / 2-1
8. / The free-power turbine gear train drives the:
a. Power-turbine tachometer-generator
b. Power-turbine governor
c. Torquemeter
d. Power Output Shaft / 2-1
9. / The engine anti-icing will remain in the last energized position in the event of an electrical fire. / 2-3
10. / The GOV RPM switch is used to set a power turbine speed (Nf) between 96 to 101 ±0.5 percent rpm / 2-4
11. / Two accumulator cans are located in line between the Nf governor and Ng fuel control to eliminate transient surges in governor reset pressure. / 2-4
12. / The engine lubrication system is a circulating dry-sump with an external oil tank and oil cooler. / 2-12
13. / Two chip detector elements, the scavenge oil outlet chip detector and the accessory gearbox chip detector are located on the accessory gearbox section of the engine and illuminate the ENG CHIP caution light. / 2-12
14. / The oil cooling fan provides cooling air for the engine oil system, the transmission oil system, and [the] hydraulic system. / 2-12
15. / Each rotor blade is twisted 5°, having more pitch at the root than at the tip. / 2-14
16. / 2¼° of preconing are built into the main rotor hub and blade assembly to relieve bending moments at the blade root. / 2-14
17. / The tail rotor driveshaft consists of eight sections connected by couplings which provide for driveshaft flexing and twisting. / 2-15
18. / The rotor brake assembly is mounted to the forward end of the freewheeling assembly. Normal operation is indicated with a constant pressure of 100 to 120 psi. / 2-15
19. / A dual focal mount aligns the transmission and isolates vibrations. A spike is mounted beneath the transmission; rivets secure the spike-well plate to the transmission deck. / 2-15
20. / The tail rotor gearbox contains three-eighths of a pint of oil and is splash lubricated. / 2-18
21. / The fuel pump operates at 650 psi minimum and 750 psi maximum. / 2-18
22. / In the event of a main generator failure in a TH-57B, the battery powers the flight and navigational equipment. / 2-21
23. / Name the four functions of the reverse current relay:
a. Prevents the generator from being connected to the line until reaching operating voltage
b. Holds the generator on the line unless voltage drops to a level where continued operation would be detrimental to equipment
c. Prevents reverse current flow
d. Protects against overloading the generator / 2-21
24. / The standby battery provides emergency power to the pilot attitude indicator only. / 2-27
25. / The standby generator provides an alternate source of power to the essential No. 1 bus in the event of a main generator failure. / 2-24
26. / When external power is required for starting, the engine requires 28 VDC at 400 amps. / 2-28
27. / Normal hydraulic pressure at 100-percent Nr is 600 ±50 psi. The caution light will illuminate if the pressure drops below 300 psi. / 2-28
28. / The hydraulic system on-off switch controls a solenoid valve called a fail-safe valve, that is spring loaded to the open or boosted position. Should an electrical failure occur, this valve would automatically open. / 2-28
29. / Pedal adjustments at either fore or aft extreme will render yaw FCS inoperative (TH-57C). / 2-30
30. / At speeds of approximately 95 KIAS and above, enough lift is generated by the vertical fin to require a slight amount of rudder. / 2-37
31. / The tailskid is stressed for loads of 200 pounds downward or 400 pounds upward. / 2-37
32. / Altimeter error with current barometric pressure set should not exceed 75 feet from known field elevation. / 2-38
33. / Excessive use of the landing light (10 minutes or more during periods of prolonged hovering or taxiing) may cause overheating with a resultant fire hazard. / 2-47
34. / The searchlight is adjustable to 120° of extension. From 0° to 60° extension, the light will rotate 90° left or right. From 60° to 120° of extension, the light will rotate 360°. / 2-48
35. / Use of the ventilating system reduces the air available to defog the windscreen. / 2-51
36. / During pressure refueling, necessary radio and electrical equipment may be on. / 3-1
37. / The engine holds 11.2 U.S. pints and uses primarily AEROSHELL 560 as its standard oil. / 3-7
38. / Maximum engine oil pressure is 130 psi except for temporary conditions up to 150 psi immediately following a cold-weather start. / 4-3
39. / With main generator on, the standby generator loadmeter should indicate 10 percent load or less. / 4-4
40. / With a density altitude of 1,500, maximum sideward airspeed is 20 knots and maximum rearward airspeed is 15 knots. / 4-8
41. / Climbs and descents during flight in IMC conditions should not exceed 1,000 feet/minute. / 4-9
42. / List the equipment needed to enter instrument meteorological conditions in the TH-57C:
a. Cyclic force trim system
b. MINISTAB flight control system (pitch and roll)
c. Main generator
d. Standby generator
e. Battery protection circuit
f. Instantaneous vertical speed indicator
g. Two attitude indicators (one automatically powered by approved standby battery source in the event of power loss)
h. One operable communication system
i. One operable navigation system appropriate to the routes to be flown
j. Radar altimeter
a. k. Other equipment as required by the operating rules / 4-10
43. / IFR operations are not permitted with any doors removed or with external loads. / 4-11
44. / Engine failures at high angles of bank may cause aircraft roll reversal characteristics. / 4-11
45. / List the equipment required for night flight.
a. All instrument and circuit breaker panel lights
b. All exterior lights
c. Operable communication radio
d. Attitude gyro
e. Radar altimeter / 4-11
46. / The effect of humidity on gas turbine engines is negligible; however, since humidity does affect air density, a noticeable effect upon rotor system performance will occur. / 6-1
47. / Wind affects helicopter performance by producing translational lift. / 6-2
48. / The maximum load for the baggage compartment cannot exceed 170 pounds. / 6-2
49. / If the STBY BATT voltage is less than 20 volts, aircraft is down for flight in IMC. / 7-6
50. / The two major steps to be taken prior to acceptance of the helicopter are a careful examination of recent helicopter discrepancies and a thorough preflight inspection. / 7-1
51. / At a minimum, discrepancies from the last 10 flights must be available in the aircraft discrepancy book (ADB) for the pilot’s perusal prior to each flight. / 7-1
52. / When rotating the blades clockwise, the blades should be turned from the hub. If unusual resistance is felt, do not force the rotation. Doing so may damage the Nf turbine. / 7-12
53. / If performing battery start, check minimum 24 volts DC. If performing APU start, ensure BAT switch is off. / 7-14
54. / If battery voltage stabilizes below 17 volts, a hot start is imminent; secure starter and utilize APU for subsequent start. / 7-16
55. / When performing battery starts, do not open the twist grip if the battery relay light is not illuminated. / 7-16
56. / Abort start if rotors have not begun to turn by 25 percent Ng or if positive transmission [oil pressure] indication is not received by 30 percent Nr. / 7-16
57. / The stab function should not be left engaged during prolonged periods while the aircraft is on the deck. This may cause the servo to overheat. / 7-20
58. / While hot refueling, monitor UHF radio and make no transmission, except in an emergency, while the fuel nozzle is connected to the aircraft. / 7-29
59. / Dynamic rollover is a phenomenon peculiar to helicopters and primarily to skid-configured/rigid gear [helicopters]. It is an accelerated [roll] about a ground attached point. / 11-3
60. / Low-frequency vibrations, one per revolution and two per revolution, are originated by the main rotor. / 11-10
61. / A precautionary landing is defined as a landing when further flight is possible, but inadvisable. / 12-1
62. / The best glide airspeed is 72 KIAS. Do not exceed 100 KIAS in sustained autorotation. / 14-1
63. / In a normal autorotation, Nr and Nf may be matched together between 92 to 96 percent steady state. / 14-4
64. / In the TH-57C, time of operation of essential No. 2 bus on battery power is approximately 40 minutes with an 80 percent charged battery. / 14-13
65. / Failure of Ng tachometer generator is usually accompanied by actuation of the ENG OUT warning horn and caution light. / 14-23
66. / A sudden loss of oil pressure in cold weather, other than a drop caused by relief valve opening, is usually due to a broken oil line. / 17-7
67. / During instrument takeoff, climbing turns should be limited to a maximum of 20° angle of bank and shall not be normally initiated prior to reaching 200 feet. / 17-3
68. / When landing in loose or powdery snow, if visual ground reference is lost, the pilot should waveoff. / 17-8
69. / Whenever possible, avoid starting the engine on glare ice to avoid the effect of torque reaction when increasing rpm. / 17-7
70. / If icing conditions are encountered during flight, effort should be made to vacate the icing environment immediately. / 17-7
71. / While taxiing in loose or dry snow, a higher-than-normal altitude is recommended to prevent white-out. / 17-9
72. / If pilot and copilot key their mikes at the same time, the pilot mike will override the copilot mike. / 18-3
73. / The KE-127 altitude encoder in the transponder system provides altitude identification of the transponder in 100 foot increments from -1,000 to +63,000 feet. / 18-9
74. / For the ADF (KR-87), the system operating range is 150 to 200 miles average, depending on terrain and atmospheric electrical phenomena. / 18-12
75. / Do not use the KLN-900 as the sole navigation source under IMC conditions. / 18-18
76. / Localized intercepts within 90° ±10° of the localizer course should be avoided because of antenna signal degradation. / 18-23
77. / The observer shall be familiar with ICS operations and shall be briefed on lookout doctrine and applicable emergency procedures. / 20-1
78. / The TH-57B/C has no special equipment to conduct search and rescue operations. / 20-6
79. / Flight personnel must advise all other flight personnel of any real or potential problem. This is the first step in crew resource management during an emergency. / 20-6
80. / The autorotational glide ratio is 3.25 at 50 KIAS and the minimum rate of descent is 1,558 fpm. The glide ratio at 72 KIAS is 4.08 with a rate of descent of 1,780 fpm. / 28-1
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