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UH-60 A/L > UH 60 Start System Description 1 > Flashcards

UH 60 Start System Description 1 Flashcards

1
Q

Discribe the UH60 engine start system

A

The engine start system is an electro-pneumatic system used to start both engines.

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2
Q

What is the caution that pertains to moving the engine PCL while pressing the starter button

A

To aviod damage to the engine start switch actuators, do not mover the EPCL from IDLE to OFF while pressing the starter button

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3
Q

What is the auto start circut?

A

During acceleration to idle, a speed sensor on the starter feeds the Ng speed information to the speed switch

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4
Q

The speed switch commands the starter valve to open until the Ng speed reaches a minimum of what % NG

A

52% NG

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5
Q

Between __% and __% NG the start valve will close extinguishing the starter caution light.

A

52%- 65%

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6
Q

How does a pilot abort an auto start sequence?

A

By pulling down on the PCL. This actuates the abort start switch and closes the starter air valve.

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7
Q

How does a pilot complete a manual start?

A

By pressing and holding the starter button during the start process, and releasing the button when the NG speed reaches a minimum of 52% NG.

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8
Q

What are 3 ways to provide air for Engine Starts

A

APU, Crossbleed, Ground Source.

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9
Q

What does the APU do for the engine start?

A

The APU supplies air to the engine selected for engine start. (turbomach and Garrett are the two types of APUS.)

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10
Q

Can an Engine start be accomplished with the APU air source availalble but NO AC power from the APU Gen?

A

Yes, If the battery is the sole source of DC power, and an air source is available( i.e. the APU available, but the APU gen is inop), only the #1 engine may be started.

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11
Q

What is the #1 engine start valve powered by?

A

The #1 engine start valve is powered by the DC essential bus, and no instruments will operate until the AC power becomes available.

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12
Q

What is the #2 enigine start valve powered by?

A

The #2 engine start vavle is powered by the #2 primary bus, and requireds an operaitonal main or APU gen, or and external power source.

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13
Q

What happens when a pilot presses the #1 engine starter button?

A

Pressing the #1 engine starter button opens the #1 engine start valve, allowing air supplied by the APU to enter the #1 starter and the #1 Engine.

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14
Q

What valve is utilized to complete a cross bleed start?

A

Cross bleed starting utilizes the bleed-air shutoff vavle to direct air from the operating engine to the opposite engine during the start sequence. Starting one engine from the other (cross bleed start) is the same as starting an engine using the APU as the air source, except the AIR SOURCE HEAT/START switch will be in the ENG position.

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15
Q

During a Cross bleed start, were does the pressure come from to start the other engine.

A

Pressure from the running engine compressor is used to start the other engine.

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16
Q

What are the requirments to accomplish a Cross Bleed start?

A

To accomplish a Cross Bleed Start, the running engine should be at 90% NG with the RPMR at 100%, and the engine anti-Ice advisory light off.

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17
Q

During a crossbleed start why might you have to raise the collective?

A

The collective may have to be raised to increase the NG to 90% as an 18% loss of the Maximum TQ available on the air source engine will be experienced during the start sequence.

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18
Q

Why would you want to use the APU during an in flight engine start?

A

A cross bleed start in flight may decrease the max TQ available from the running engine by as much as 18%. Therefore, the APU should be used.

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19
Q

What is an AGPU used for?

A

The AGPU is an external air source used for engine starting.

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20
Q

What are 2 sources of external engine starts?

A

Aircraft to Aircraft (buddy Start) and AGPU

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21
Q

Where does the pneutic tubing start and end?

A

The pneumatic tubing and manifold used during the engine start sequence, extends from the left side of the transmission sectoin throughout the cabin suction upper deck area forward to the heater.

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22
Q

What is the first section of the pneumatic tubing and what does it do?

A

The first seciton of the pneumatic tubing is the nipple check valve. The nipple check vavle provides a connection point for external air source.

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23
Q

Name all of the sections of pneumatic tubing in sequence.

A

Lower tube, middle tube, upper tube, front tube, cross bleed tube, and the APU compartment front tube connects to the cross bleed tube.

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24
Q

Discribe the Pneumatic tubing.

A

The pneumatic tubing consists of a series of coupled or welded tubes joined together so any one of the air sources may provide bleed air for whatever reason depending on demend.

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25
Q

Discribe the pneumatic system.

A

The pneumantic system is comprised of a series of tubing and valves that distribute compressed air to bleed air dependant systems.

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26
Q

Pneumatic tubing is not allowed any dents that exceed __% of the total diameter of the tube in question.

A

25%

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27
Q

Are cracks allowed on pneumatic tubes or joints?

A

NO

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28
Q

Where are the starter contol Valves located

A

the start control valves are located inside the oil cooler compartment, inboard of each respective engines firewall.

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29
Q

The start control valves are _______ controled and ___ ______ to allow bleed air to flow through to the engine starter.

A

The start control valves are electrically controlled and air actuated to allow bleed air to flow through to the engine starter.

30
Q

When the starter button is pressed, the start control valve is electrically opened by the ______ ______.

A

When the starter button is pressed, the start control valve is electrically opened by the solenoid valve.

31
Q

What happens when the start control valve is opened?

A

Opening the start control valve released compressed air from the air source to the air turbine starter of the engine being started. The air entering the start control valve is filter to remove impurities as it passes through the start control valve.

32
Q

Both start contol valves require __-__ psi bleed air to actuate.

A

Both start contol valves require 27-31 psi bleed air to actuate.

33
Q

The __ ______ ____ (#1 start system) provides voltage through the #1 ___ ______ circut breaker to ____ relay in the left relay panel to energise the #1 engine start control valve.

A

The DC ESNTL BUS (#1 start system) provides voltage through the #1 ENG Start circut breaker to K45 relay in the left relay panel to energise the #1 engine start control valve. This voltage is removed during start sequence by pulling down on the #1 EPCL.

34
Q

The __ __ _____ ____ (#2 Start system) provides voltage through the #2 _____ ____ _____ circut breaker, to ___ relay in the right relay panel, to energize the #2 engine start control valve.

A

The #2 DC PRI BUS (#2 Start system) provides voltage through the #2 ENG Start CONTROL circut breaker, to K26 relay in the right relay panel, to energize the #2 engine start control valve. This Voltage is removed during start sequence by pulling down on the #2 EPCL.

35
Q

Where are the Bleed Air shut off valves located?

A

The bleed air shut-off valves are located inside the oil cooler compartment below the start control valves.

36
Q

Describe the bleed-air shut off valve.

A

The bleed air shut off valves are electrically controlled and air actuated to allow bleed-air to flow through the pressurize the entire pneumatic manifold.

37
Q

The bleed-air shutoff valve is _________ actuated and ____________ opened.

A

The bleed-air shutoff valve is electrically actuated and pneumatically opened. An electric solenoid allows the bleed-air valve to poen when air is being forced out.

38
Q

What prevents the bleed-air valve and start control valve from being opened at the same time.

A

The start relays prevent the bleed-air valve and start control valve from being opened at the same time.

39
Q

Power to the bleed-air shutoff valve is provided by the___ ____ _____ _____, through the Air Source Heat Start switch and the respective start relay.

A

Power to the bleed-air shutoff valve is provided by the #1 DC PRI BUS, through the Air Source Heat Start switch and the respective start relay.

40
Q

What is the APU check Valve?

A

The APU check valve is a one-way check valve that allows the apu to pressurize the pneumatic manifold, but prevents air from being forced back through the APU when it is not operating.

41
Q

Where is the APU check valve located?

A

The APU check valve is located on the lower left hand side of the APU just forward of the firewall for the APU.

42
Q

What is an APU start bypass valve?

A

The APU start bypass valve is an electrically actuated valve that allows excess air to be dumped overboard until need for engine start. The valve opens to unload the compressor during the start sequence, preventing compressor stalls.

43
Q

What controls the APU start bypass valve?

A

The APU start bypass vavle is controlled by the APU Electronic Sequence Unit (ESU) and relay K22 in the right relay panel.

44
Q

Where is the #1 Starter located?

A

The #1 engine starter is located on the accessory gearbox inner side near the firewall.

45
Q

Where is the #2 Starter located?

A

The #2 engine starter is located on the accessory gearbox outer side.

46
Q

What does the Air turbine starter do?

A

The Air turbine starter converts pneumatic air pressure into mechanical force that turns the engine’s accessory drive and NG section.

47
Q

What is the purpose of the air turbine starter’s Shear Shaft?

A

The starter has a small shear shaft, which allows the engines accessory drive to continue to rotate in the event the starter seizes up.

48
Q

What is the purpose of the magnetic speed sensor on the air turbine starter?

A

The speed sensor is located on the engine starter and provides an AC signal, proportional to engine speed, this signal is fed to the speed switch (auto-start circut) to effect starter dropout between 52-65% NG.

49
Q

When does the Air turbine starter decouple from the AGB and PTO?

A

The pneumatic stater is powered by bleed air, it motors the NG section via the AGB and PTO. It decouples (via internal clutch) when engine RPM is greater than starter.

50
Q

Why do starter limitations exist?

A

Starter limitations exist because the bleed air powering it is HOT (400 F) and can damage the starter if exposure time is excessive.

51
Q

What is the Starter Switch?

A

The starter switch is a micro switch that is activated by the retarded engines power control levers starter button. When pressed, the starter switch allows voltage to pass through to energize the start relay.

52
Q

What is the over ride switch?

A

The over switch is adjusted to allow activation by the start button if activated. This switch and the starter switch can be activated either together (PCL Retarded) or seperately (PCL Idle) in the event of a starter that will not stay engaged. It allows voltage to pass through the energize the start relays and also to light the starter caution light (false start light).

53
Q

Where is the abort switch.

A

The Abort switch is located on the forward side of the EPCL

54
Q

What does the Abort switch do?

A

The abort switch is a micro switch that is adjusted to allow activation when the PCL is pulled down. Acitivation of the abort switch removes voltage from the start relays and ultimately the start control valve. The abort switch will activate regardless of PCL positon.

55
Q

Where is the starter speed switch located?

A

The starter speed switch is located in the upper cabin area above the left-hand gunners station.

56
Q

What does the starter speed switch do?

A

As engine speed increases, the speed pickup sensor produces an ac signal that electrically energizes the starter speed switch, holding the engine start relay in the energized positon.

57
Q

At what Ng speed does the starter switch deactivate, and what does it do?

A

52-65%NG, closes the engine starter control valve.

58
Q

The Starter speed switch performs the AUTO HOLD FUNCTION of the engine start system by using signals from the?

A

The Starter speed switch performs the AUTO HOLD FUNCTION of the engine start system by using signals from the speed sensors and voltage from the start control valves.

59
Q

If the Keylock ignition switch is in the OFF position, do motoring capabilities remain?

A

Yes.

60
Q

What happens when the Engine Ignition switch is placed in the ON position?

A

When the ENGINE IGNITION switch is in the ON position, the short is removed from both engine alternators, allowing current flow to the ignition exciter and to the igniter plugs.

61
Q

Where is the #1 engine starter relay and what is the relay #.

A

The #1 engine starter relay (k45) is located in the left relay panel.

62
Q

Where is the #2 engine starter relay and what is the relay #?

A

The #2 engine starter relay (K26) is located in the right relay panel.

63
Q

Where are the prime shutoff valves located?

A

The prime shutoff valves are located on the top inboard center of the main fuel cells.

64
Q

What opens the prime shut off valve?

A

The Engine starter relay opens the prime shutoff valve. The Engine fuel system is primed when the prime shutoff valve is opened.

65
Q

Where is the prime boost pump located?

A

The prime boost pump is locatd on top of the right main fuel cell.

66
Q

What happens when the fuel pump switch is placed in the fule prime position?

A

When the switch is in the FUEL PRIME position the prime boost pump is energized and the prime shutoff valve to each main engine fuel supply line is opened. This mode will illum the PRIME BOOST PUMP ON capsule on the caution/advisory panel.

67
Q

Starter will not stay engaged. (Starter light going out when starter button released)

A

If this malfuntion occurs, the auto-start system is malfunctioning and the pilot should conduct a manual start.

68
Q

No Rise in TGT, Oil pressure, or %RPM 1 or 2.

A

Conduct an Emergency Engine shutdown. No %rpm 1 or 2 could be because of gust lock engaged. No rise in TGT before 45 seconds could be caused by ignition key in Off position. ( in this case do not turn the key to the on position, this will ignite all of the fuel in the combustion chamber.

70
Q

TGT rise above 850

A

If TGT rises above 850 during engine start sequence, an emergency engine shutdown must be completed, and starter motored until tgt is below 538.

71
Q

Starter Dropout prior to 52% NG

A

the NG section needs starter assist until 52% NG speed. If the starter drops out too soon a hot start may result, complete an emergency engine shutdown.

73
Q

Starter does not disengage past 65% NG

A

Pull downward on the malfuntioning PCL actuating the abourt switch. If this does not cause starter drop out, the start valve is stuck in the open position, and hot air will eventually damage the starter. The pilot must remove air source as required.

UH-60 A/L (7 decks)

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