Brainscape's Knowledge GenomeTM

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


See full index

Systems > ENG OVERALL > Flashcards

ENG OVERALL Flashcards

1
Q

What is the engines name / what type is it?

A

T700-GE-401C/D // A front-drive turboshaft engine

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

List the five sections of the T700-GE-401C/D engine.

A
  • Inlet
  • Compressor
  • Combustor
  • Turbine
  • Exhaust

These sections work together to facilitate the engine’s operation.

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

What does HMU stand for

A

Hydromechanical Control Unit

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

What is the role of the enhanced digital electronic control unit (EDECU)

A

To provide advanced engine control and monitoring

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

What system does the T700-GE-401C/D engine use for lubrication?

A

A self-contained lubrication system

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

What component in the eng is responsible for boosting fuel pressure?

A

Engine-driven fuel boost pump

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

The HMU is responsible for controlling what? ( Think big picture))

A

The HMU is responsible for controlling fuel flow and engine performance.

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

How is the inlet cowling heated to prevent ice formation?

A

Using fifth stage bleed air via the inlet anti-ice valve

This heating mechanism is crucial for maintaining airflow and engine performance in cold conditions.

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

What feature of the inlet fairing allows for anti-icing?

A

Perforated with small slits

These slits enable fifth stage bleed air to heat the exposed inlet surface.

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

What is the function of the swirl vanes in the inlet section?

A

To impart rotation to the airflow

This rotation is essential for effective airflow management and particle separation.

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

What does the Inlet Particle Separator (IPS) do? Keep this one get rid of the other one

A

Prevents foreign particles from entering the compressor

The IPS uses centrifugal force to eject particles into a collection scroll.

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

What happens to the discharge airflow from the IPS?

A

It passes over the scroll vanes and is then dumped overboard through the blower assembly

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

What is the role of the deswirl vanes in the inlet section?

A

To remove the rotation, This provides smooth airflow to the compressor.

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

What does the compressor section consist of?

A

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

These components work together to compress the incoming air for combustion.

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

What are the key components of the combustion section?

A

Flow-through annular combustion chamber, two igniters, 12 fuel injectors

These components are essential for the combustion process in the engine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the four functions of the Overspeed and Drain Valve (ODV)? (H: PRTP)

A
  1. Provides main fuel flow to the 12 fuel injectors during engine start and operation.

2.) Returns fuel back to the HMU if the Np overspeed is energized or if the EDECU hot start preventer is activated

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.)Purges the main fuel manifold overboard, after engine shutdown, through a shutoff and drain valve to prevent coking of the fuel injectors.

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

What drives the compressor and Accessory Gearbox (AGB)

A

The Ng turbine drives the compressor and Accessory Gearbox (AGB)

The N g turbine is a two-stage, air-cooled, high-performance axial design.

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

What percentage of the total airflow through the engine is used for combustion?

A

Approximately 30 percent of the total airflow is used for the combustion process.

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

List the uses of the remaining airflow in the engine.

A
  • Compressor inlet temperature (T2) air
  • Compressor discharge pressure (P3) air
  • Combustor and turbine cooling
  • Engine oil seal pressurization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What components are driven by the rear face of the AGB? ( H: Car Store)

A
  • Engine starter
  • HMU
  • IPS blower
  • Overspeed and Drain Valve (ODV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Who are the major players for the Eng control System ( 4 Player)

A
  • HMU
  • ODV
  • EDECU
  • Engine-driven alternator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does the HMU interact with the EDECU in the Engine Control System?

A

The HMU controls the gas generator while the EDECU trims HMU to satisfy the load requirements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens when the PCL is in the OFF position?

A

The Power Available Spindle (PAS) mechanically shuts off fuel at the shutoff valve within the HMU.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does moving the PCL to the IDLE position accomplish?

A

It allows the HMU to automatically control start sequence fuel flow for self-sustaining combustion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the function of the Load Demand System? I like this one better than the other one.

A

The Load Demand System automatically controls engine speed and provides required power based on collective position.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the two main purposes of the engine-driven fuel boost pump?

A
  • Provide reliable suction feed from the aircraft fuel tank to the engine
  • Provide discharge pressure to satisfy the HMU’s minimum inlet pressure requirement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Fill in the blank: The _______ is designed to minimize vulnerability and fire hazard in the event of damaged fuel lines.

A

engine-driven fuel boost pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How many stages does NG have

A

The N g turbine is a two-stage, air-cooled, high-performance axial design.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where does fuel come from before entering the fuel filter?

A

From the engine-driven fuel boost pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens when a pressure differential across the fuel filter is sensed?

A

The impending bypass Pressure Differential Indicator (PDI) extends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Can the impending bypass PDI be reset without maintenance?

A

No, it cannot be reset until the filter element is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What caution appears once the filter is bypassed? Referring to Fuel

A

1/#2 FUEL FLTR BYPASS caution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the role of the metering valve in the HMU?

A

To ensure proper fuel flow to the engine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does the HMU respond to in terms of cockpit inputs?

A
  • First mechanical input from the LDS
  • Second mechanical input from the PCL
  • Electrical signal from the EDECU
35
Q

What are the functions of the HMU in response to the PCL?

A
  • Fuel shutoff
  • Setting engine start fuel flow
  • Setting permissible N g up to maximum
  • Fuel priming
  • EDECU override capability (LOCKOUT)
36
Q

What inputs does the HMU respond to that influence fuel flow?

A
  • T2
  • P3
  • N g
37
Q

What is the function of the HMU when there is no input to the torque motor from the EDECU?

A

Operates as a conventional gas-generator power control

38
Q

What feedback mechanism does the HMU use to tell the EDCU it can stop trimming down power?

A

Provides a feedback signal to the EDECU via the LVDT

39
Q

What happens to excess fuel in the HMU?

A

Routed back to the pump inlet

40
Q

At what point does the N g overspeed valve trip?

A

At 110 ±2 percent N g

41
Q

What is the purpose of having the actual level of engine power in FLY set higher than required?

A

To ensure fail-safe to high power and available power with One Engine Inoperative (OEI)

42
Q

What are the functions provided by the HMU?

A

Rapid engine transient response, automatic fuel scheduling for engine start, Ng overspeed protection, N g governing, acceleration limiting, flameout and compressor stall protection

43
Q

What is the primary function of the alternator in the engine?

A

Powers all essential engine electrical functions

44
Q

What inputs does the EDECU receive from the cockpit?

A
  • ENG SPD TRIM switch
  • CONTGCY PWR switch
  • ENG OVERSPEED TEST A and B buttons
45
Q

What signals does the EDECU send to the cockpit? (Look UP)

A
  • Torque
  • Np
  • TGT
  • Contingency power
46
Q

At what Np percentage does the overspeed system get actuated?

A

120% Np

Exceeding this limit triggers a signal to divert fuel, causing engine flameout.

47
Q

True or False: Resetting a popped NO. 1 or NO. 2 ENG OVSP circuit breaker in flight is safe.

A

False

It may initiate an engine overspeed signal and result in engine failure.

48
Q

What is the purpose of TGT limiting in the EDECU?

A

To limit fuel flow when measured TGT exceeds a fixed reference TGT

The reference TGT is also known as the MRP limiter setting.

49
Q

How does the engine load sharing function in the EDECU?

A

Compares torque signals between two engines and generates a torque error signal

The EDECU increases power on the lower torque engine.

50
Q

What does the ENG SPD TRIM switch do?

A

Controls Np of both engines simultaneously

It does not provide individual engine trim capability.

51
Q

Fill in the blank: The CONTGCY PWR switch allows TGT to increase above the _______.

A

MRP limiter setting

52
Q

What triggers the auto-contingency power feature?

A

When torque from one engine is below 50%

The opposite engine’s EDECU will reset the TGT limiter.

53
Q

What conditions must exist for dual-engine auto-contingency power to activate?

A
  • TGT within 11 °C of MRP limiter setting
  • N p drops below 96%
  • Greater than 3% droop between actual N p and reference set point
  • Greater than 5% per second N p droop rate
54
Q

What does the Np overspeed test involve?

A

This lowers the N p overspeed limit from 120% to 96%.

55
Q

What happens when the EDECU is in LOCKOUT mode?

A

Manual control of Ng and Np is enabled

Engine power is no longer controlled by the EDECU.

56
Q

What does the hot start prevention feature detect?

A

A hot start when TGT exceeds 900 °C with low Ng and Np

It stops fuel flow and restores it when TGT decreases.

57
Q

What is the purpose of the transient droop improvement (TDI) system?

A

Initiates power turbine acceleration early

It uses anticipator signals to increase fuel flow at low torque settings.

58
Q

What does the auto-ignition system do during an Np overspeed condition?

A

Automatically initiates ignition sequence for 5 seconds

It cycles until the N p overspeed condition is controlled.

59
Q

What is the Ng decay rate relight feature / at what % Ng does it deactivate it`s self?

A

Turns on igniters for 5 seconds to relight the engine if it flames out

This feature is disabled below 62% N g.

60
Q

What does the fault diagnostic system in the EDECU do?

A

Identifies failed components or circuits with fault codes

Codes are displayed on the engine torque indicator with descriptions.

61
Q

What three things does the Alternator provide AC power to

A

Ignitor assembly, EDECU, and Ng signal to the vertical instruments.

62
Q

What is the purpose of the thermal lockout in the impending bypass below what temperatures?

A

It prevents the indicator from popping during cold-weather starting below 38 °C.

This feature ensures accurate readings during low-temperature conditions.

63
Q

How does the oil cooler function/ Where does it flow too after the Oil Cooler?

A

It transfers heat from the oil to fuel, cooling the oil as it passes through.

After the oil cooler, it flows through scroll vanes that also cool the oil.

64
Q

What are the three pneumatic sources for engine starts?

A
  • Auxiliary Power Unit (APU)
  • Engine crossbleed air
  • External pneumatic power
65
Q

What does the AIR SOURCE ECS/START switch do?

A

It selects the source of air pressure for engine start and ECS operation.

66
Q

What happens when the starter button is pressed?

A

Air from the selected source is directed through the start valve to the engine starter.

67
Q

What is the minimum N g for the receiving engine in a crossbleed start?

A

24 percent N g.

This requires the donor engine to have an N g of approximately 90 to 94 percent.

68
Q

Fill in the blank: The #1/#2 ENG ANTI-ICE ON advisory will remain until the _______ is closed.

A

anti-ice/start bleed valve

69
Q

What does the engine anti-ice/start bleed valve provide when anti-ice is selected ON?

A

Fifth stage bleed air

The valve automatically opens during engine starts.

70
Q

At what Ng percentage does the anti-ice/start bleed valve remain open during engine starts / why does it remain open?

A

Below 80.5% N g

This is to prevent compressor instability during starts.

71
Q

Anti-Ice/start bleed value should be closed above what % Ng / what are the two reasons why it might not be closed ?

A

96.5 % Ng / It closes unless anti-ice is selected ON or electrical power is lost

The range of acceptable Ng speeds at which the valve operates is dependent on OAT.

72
Q

What (3) thing indicate a malfunctioning anti-ice/start bleed valve?

A

Any of the following:
* Appearance/disappearance of ENG ANTI-ICE ON advisory outside specified range
* No appearance of ENG ANTI-ICE ON advisory when switch is ON
* No rise in TGT when switch is ON

With ENG ANTI-ICE ON, maximum torque available is reduced up to 18% per engine.

73
Q

What temperature does the inlet thermal switch activate the INLET ANTI-ICE ON advisory?

A

Approximately 93 °C

Full inlet anti-ice capability may not be available above 4 °C.

74
Q

What happens with the NO. 1 and NO. 2 ENG ANTI-ICE switches OFF?

A

The solenoid is energized and the valve is closed

When the switches are ON, the valve is variably open based on OAT.

75
Q

What controls the engine inlet anti-ice valve when the switches are OFF and ice is detected?

A

The valve is variably open based on OAT

This occurs with the DE-ICE MASTER switch ON.

76
Q

How does the Freon-filled bellows operate in relation to the inlet anti-ice valve?

A

It reacts to ambient temperature and controls the valve

77
Q

What indicates a malfunctioning engine inlet anti-ice valve?

A

Appearance of the INLET ANTI-ICE ON advisory when OAT is greater than 13 °C

The resultant loss of torque could be a maximum of 49% when the anti-ice valves are open.

78
Q

Based off the Freon-Filled Bellows when is the Value open/ value begins to close/ and is completly closed ?

A

Less than 4 °C: valve open; 4 to 13 °C: valve closes; above 13 °C: valve closed.

79
Q

What are the 16 Functions of the EDCU?

A

1.) Ng Govering
2.) Eng speed trim.
3.)Np Overspeed Test.
4.) Np overspend Protection
5.) Auto Ignation
6.) Ng Decay rate relight feature
7.) Load Sharing
8.) TGT Limiting
9) Manual C-Power
10) Auto- C Pwr
11) Dual Engine Auto
12) Transient droop improvement
13.) Cockpit Signals
14.) EDECU Lockout
15.) Hot Start Prevention
16.) Fault Diagnostic

80
Q

The EDECU receives the following input signals from the helicopter:

A
  1. Torque from the other EDECU.
  2. N p demand.
  3. 400-Hz backup power.
  4. HMU (LVDT).
81
Q

The EDECU receives the following inputs from the cockpit: (H: How can I influence the EDECU on the ground?)

A
  1. ENG SPD TRIM switch.
  2. CONTGCY PWR switch.
  3. ENG OVERSPEED TEST A and B buttons.
82
Q

What is the MRP Limit?

A

866+/-10

83
Q

What is the CRP

A

891+/- 10

Systems (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions