Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MH-60R H2P > Powerplant and related > Flashcards

Powerplant and related Flashcards

1
Q

Name of the engine

A

T700-GE-401C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Type of engine

A

Front-drive turboshaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The waterwash manifold is an integral part of the _____, which aims a series of jets into_______.

A

swirl frame, compressor inlet area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

After passing through the _____, airflow passes through the ________ which impart rotation to the airflow.

A

inlet cowling, swirl vanes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The swirl vanes are ______, to allow passage of fifth stage bleed air via the _____ for anti-icing purposes.

A

hollow, engine anti-ice valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The _____ prevents foreign particles from entering the compressor. The rotation of the airflow, imparted by the swirl vanes, causes the particles to be thrown outward into _______.

A

inlet particle separator (IPS), the collection scroll

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Before discharge airflow is dumped overboard through the _______, it passes over the ______, which are contained in the collection scroll.

A

blower assembly, swirl vanes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

After passing through the IPS, clean air passes through the _____, which remove the rotation, providing smooth airflow to the ______.

A

deswirl vanes, compressor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The compressor section consists of_______

A

five-stage axial and single-stage centrifugal rotor/ stator assembly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The combustion section consists of________

A

flow-through, annular combustion chamber
two igniters
12 fuel injectors (receive fuel via the ODV and supply atomized fuel for combustion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The Ng turbine drives the _____ and ______.

It is a _____________ design.

A

compressor and accessory gearbox (AGB),

two-stage, air cooled, high performance axial design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The Np turbine has two stages that turn the ______

A

power turbine driveshaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The Np shaft is______, turning inside the _______.

It extends through the front of the engine where it connects to the _______, which in turn connects to the ______.

A

coaxial, inside the Ng turbine driveshaft

high speed shaft, input module

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

TGT is sensed between___________.

A

gas-generator and power turbine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Approximately _________ percent of total airflow through the engine is used for the combustion process. The remainder is used for:

A

30 percent for combustion

  1. Compressor inlet temperature (T2) air
  2. Compressor discharge pressure air (P3)
  3. Combustor and turbine cooling
  4. Engine oil seal pressurization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The AGB is driven by _______

A

a rotor via the radial driveshaft from the Ng turbine driveshaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Purpose of the Engine Control System

A

to maintain a constant Np/Nr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The HMU provides________, while the DECU ____________.

A

gas generator control, trims the HMU to satisfy the requirements of the power turbine load and reduce pilot workload.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens in DECU lockout

A

The PCL is used to manually control Np/ Nr. TGT limiting, Np governing, and load sharing functions are deactivated. Np overspeed is retained via a direct link between the DECU and ODV.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

A _____ on the engine control quadrant activates a _____ to prevent the PCLs from being advanced above IDLE with the rotor brake on. If the rotor brake is relased, the ______ energizes and unlocks the PCLs. An _______ is provided on the quadrant, should the _____ fail.

A

solenoid, mechanical locking device
solenoid
override tab
solenoid

21
Q

The engine driven boost pump on the forward side of the AGB is designed to do 2 things….

A
  1. Provide reliable suction feed from the tank to the engine, minimizing vulnerability and fire hazard in the event of damaged fuel lines
  2. Provide discharge pressure to satisfy the minimum inlet pressure requirement of the HMU or high-pressure fuel pump
22
Q

Fuel leaves the high pressure pump, passes through the metering valve and shutoff valve and is then directed through an external line to the oil-to-fuel heat exchanger. Some fuel is tapped to operate various servos in the HMU for the following:

A

“Ms V’

  1. Positioning the METERING valve to ensure proper fuel flow to the engine
  2. Positioning a SERVO piston that actuates the variable geometry vane servo and start bleed valve.
  3. Amplifying VARIOUS signals (T2, P3, Ng) that influence fuel flow and variable geometry servo position
23
Q

T2, P3 and Ng inputs aid the HMU in controlling _______ and ________ during engine start and normal operation, reducing the chance of compressor stall.

A

variable stator vanes and anti-ice/ start bleed valve position

24
Q

After fuel leaves the ______, it is routed to the ________, which schedules fuel flow commensurate to the current power demand and is trimmed to the required level by the _____ in response to DECU signals.

A

high-pressure fuel pump, metering valve, torque motor servo

25
Q

The HMU, via the _______, provides feedback to the DECU to null the torque motor servo input, stabilizing metering valve movement and preventing ________. Excess fuel is then routed back to______

A

LVDT, preventing engine oscillation/hunting, the pump inlet

26
Q

The Ng overspeed valve is set to trip at_____. A spring loaded ball valve ports fuel pressure causing the minimum pressure valve to secure flow to the engine.

A

110 plus or minus 2 percent

27
Q

The actual level of engine power in FLY is normally more than required by the helicopter. It’s intentionally placed at a higher level for 2 reasons:

A
  1. Fail safe to high power. There are enough engine protection functions within the HMU that neither engine damage nor stall can occur during or following loss of the electrical signal to the torque motor. All you need to do after a failure is retard the PCL manually to a more desirable level
  2. Power available with OEI.
28
Q

The HMU provides:

A
  1. Rapid engine transient response through collective compensation
  2. Automatic fuel scheduling for engine start
  3. Ng overspeed protection. Mechanically limits Ng to 110 plus or minus 2
  4. Ng governing. HMU receives T2, P3, and Ng inputs from their respective sensors, which are used to schedule fuel for minimum flow, max flow, and VGV control
  5. Accelerating limiting. Ng governor ensure any PCL motion will result in safe engine operation and not cause engine damage. Inadvertent shutdown will not occur.
  6. Flameout and compressor stall protection. HMU adjusts variable geometry vane position and opens the anti-ice/ start bleed valve to prevent compressor instability.
29
Q

When the PCL is advanced to IDLE, the shutoff valve in the HMU opens and allows metered fuel to flow to the ODV, which has four main functions:

A
  1. Provides main fuel flow to the 12 fuel injectors during engine start operation.
  2. Purges the main fuel manifold overboard, after engine shutdown, through a shutoff and drain valve to prevent coking of the fuel injectors
  3. Traps fuel upstream, which keeps the fuel/ oil heat exchanger full, so that system priming is not required prior to the next start.
  4. Returns fuel back to the HMU if the Np overspeed is energized or if the DECU hot start preventer is activated.
30
Q

All essential engine electrical functions are provided by the _______. The engine alternator contains separate windings providing ___ power to the _____, ______, and ____ signal to the vertical instruments.

A

alternator, AC, ignitor assembly, EDECU, Ng

31
Q

Np Governing

A

The Np sensor located on the left side of the power turbine section provides an Np signal to the EDECU. Actual Np is compared to a reference Np to compute a speed error input signal for use in electrical control computation.

32
Q

Np Overspeed Protection

A

The Np overspeed system is composed of redundant circuits, which rely on a signal from the Np overspeed and torque sensor located on the right side of teh power turbine section. The overspeed system is actuated at 120% Np. WEhen Np exceeds 120%, a signal is sent from the EDECU to the ODV, diverting fuel to the inlet of the HMU, causing engine flameout.

Warning: A popped No. 1 ENG OVSP or No. 2 ENG OVSP cb shall not be reset in flight. Resetting a popped No. 1 or No. 2 ENG OVSP cb may initiate an engine overspeed signal and result in engine failure.

33
Q

TGT Limiting

A

Measured TGT is compared to a fixed reference TGT. When the temperature is above the reference, a signal is generated to reduce fuel flow. When TGT approaches 878 C, the EDECU prevents any further increase in fuel flow to the engine. The EDECU incorporates a maximum rated power (MRP) limiter that limits TGT to 866 plus or minus 10 C. If power demand is increased further, Np/Nr will droop below 100%; Np governing will be sacrificed to protect the engine against overtemperature.

34
Q

Engine Load Sharing

A

Torque signals are compared between the two engines via the respective EDECUs. A torque error signal is generated if one engine torque is less than the other. The torque matching system operates by increasing power on the lower torque engine, while not directly affecting the higher torque engine.

35
Q

Engine Speed Trim

A

An ENG SPD TRIM switch, located on the upper console, with positions INCR and DECR, controls the Np of both engines simultaneously. There is no individual engine trim capability. The ENG SPD TRIM switch supplies a reference electrical signal to the EDECUs for controlling Np as required between 96 and 101% Np.

36
Q

Manual Contingency Power

A

The TGT limit can be increased by placing the CONTGCY PWR switch on the collective to the ON position. This sends a signal to the EDECU to allow TGT to increase to 903 °C; however, the maximum contingency range power (CRP) limiter will prevent further increase in fuel flow to the engine at 891 °C ±10 °C. The #1 and #2 ENG CONTGCY PWR ON advisories indicate that contingency power has been selected. Placing the CONTGCY PWR switch to the ON position automatically deactivates the environmental control system (ECS).

37
Q

Auto Contingency Power

A

In addition to existing manual contingency power, the EDECU also provides automatic contingency power, enabled in OEI conditions. When the torque from one engine is below 50% (180 ft-lb), the opposite engine EDECU will automatically reset the TGT limiter from 866 °C ±10 °C to a maximum limit of 891 °C ±10 °C. The #1 and #2 ENG CONTGCY PWR ON advisories will not illuminate to indicate that contingency power has been activated.

38
Q

Dual-Engine Auto-Contingency Power

A

Dual engine auto-contingency power allows the EDECU to bypass the 10-min TGT limit of 866 °C ±10 °C, and limit the aircraft at the contingency power TGT limit of 891 °C ±10 °C. For this feature to activate, one or more of the following conditions must exist:

a. Np drops below 96%.
b. Greater than 3% droop between reference power turbine speed (Np) and actual Np reference set point.
c. Greater than 5% per second Np droop rate exists with Np less than or equal to Np reference set point.

39
Q

Np Overspeed Test

A

The test mode is activated by the ENG OVERSPEED TEST A and B buttons. When both switches are actuated, the Np overspeed limit is re-referenced to 96% Np. If power turbine speed decreases when either switch is pressed individually, the opposite test switch may be faulty

40
Q

EDECU Lockout

A

After being moved momentarily to LOCKOUT, the PCL is used to manually control Ng and Np. As a result, engine power is no longer controlled by the EDECU; it is set by PAS and LDS positions only. With the PCL in LOCKOUT, the torque motor servo is disabled, therefore deactivating TGT limiting, Np governing, and load sharing. The Np overspeed protection system is retained when in LOCKOUT. To regain automatic engine control, the PCL must be moved to IDLE then returned to FLY.

41
Q

Cockpit Signals

A

Provides Np, TGT, and torque signals to data concentrator (DTC) for cockpit display.

42
Q

Hot Start Prevention

A

Detects a hot start when TGT exceeds 900 °C with Ng below 60% and Np below 50% and automatically stops fuel flow by tripping the ODV. Fuel flow is restored when TGT either decreases to 300 °C or after 25 seconds, whichever occurs first. Hot start prevention can be disabled by pressing and holding the ENG OVSP TEST A or B button for the duration of the start sequence. A self-test of the hot-start prevention system is performed while conducting a normal Np overspeed system test.

43
Q

Fault Diagnostic System

A

The EDECU incorporates signal validation for selected input signals within the electrical control system. If a failure has occurred while the engine is operating, the failed component or related circuit will be identified by a preselected fault code. It is possible to have more than one fault code detected and each code should be treated as an individual fault. Once both engines are shut down, fault codes will be displayed numerically on the engine torque indicator with a brief description in text below the vertical instruments on the WCA page. Codes are displayed starting with the lowest code (4 seconds on and 2 seconds off), rotating through all codes, and then repeating the cycle. They can be suppressed and recalled by pressing either one of the ENG OVSP TEST buttons. Once the problem has been corrected, the codes will be cleared and may be verified after operating the engine at FLY.

44
Q

Note: Failure to suppress the EDECU fault codes will prevent ____________ due to the torque signal
being relayed to the AFCC computer.

A

AFCS ground checks and automatic blade fold from operating

45
Q

Transient Droop Improvement

A

The TDI system is designed to initiate power turbine acceleration early by using anticipator signals from the TDI Nr sensor located on the left accessory module and a collective position sensor in the mixing unit. Circuits in the EDECU increase fuel flow to the engine via the HMU torque motor servo at low torque settings when collective demand is increased rapidly or in the event of rapid Nr decay

46
Q

Auto Ignition System

A

When an Np overspeed condition is reached and during the Np overspeed test, the overspeed valve located in the ODV is opened to reroute fuel flow to the HMU inlet. When Np drops below 120%, the auto-ignition system closes the overspeed valve and turns on the igniters for 5 seconds to relight the engine. The Np overspeed/auto-ignition system will continue cycling until Np/Nr is controlled. A yaw kick may be experienced each time engine relights.

47
Q

Ng Decay Relight Feature

A

The auto-ignition system also includes an Ng decay rate relight feature. If an engine flames out for any reason and exceeds a specified Ng deceleration rate, the auto-ignition system will turn on the igniters for 5 seconds in an attempt to relight the engine. The Ng decay rate relight feature is disabled below 62% Ng.

48
Q

The ac powered ignition system includes an ignition exciter unit, mounted on the right side of the engine main frame, and _________ .

A

two igniter plugs

MH-60R H2P (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions