Engine Systems (work in progress) Flashcards by Z Z

What are the 5 major sections of the CFM F108-CF-100 engines?

1) Fan
2) High Pressure Compressor
3) Combustion
4) Turbine
5) Accessory section

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What are the main parts of the:

Fan Section

Fan + 3-stage low pressure compressor
80% of T/O thrust
Fixed stators
PMC’s above 70% N1. Trims MEC

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What are the main parts of the:

High Pressure Compressor

9 Stages
First 3 have variable inlet guide vanes

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What are the main parts of the:

Combustion

Dual ignition, 20 fuel nozzles, annular ring
Fuel metered by MEC
Igniters at 4 o’ clock, 8 o’clock

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What are the main parts of the:

Turbine

High and Low pressure
High: 72 blades, single stage powers high pressure compressor
Low: 4 stages, powers fan + low stage compressor

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What are the main parts of the:

Accessory section

Mechanically driven by high press. compressor (N2)
Located at engine 6 o’clock
Engine fuel pump
Main Engine Control (MEC)
Hydraulic Pump
Constant Speed Drive
Generator
Control Alternator
Lubrication Unit

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Controls and Indicators:

Function of the Throttle Quadrant?

Controls the engine RPM through the MEC with the PMCs off

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Controls and Indicators:

Function of the Engine Ignition Control and Start Panel

IGNITION provides constant spark through full throttle movement. Does NOT open the starter valve
START opens the starter valve and provides spark between 1/2 way to START and IDLE
Starter valve light on when valve opens with 5 degrees

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Controls and Indicators:

Function of the Engine Oil Pressure Warning Lights

On below 11 psi or if filter clogged
Off above 13 psi

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Controls and Indicators:

Function of the PMC panel?

Connects PMC to respective MEC
Switch powered by respective engine

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Controls and Indicators:

Function of the Engine Fire/Overheat Detection and Extinguishing Controls?

Compartment Hot lights
Fire Lights
Fire EXT Light
Fire Switch
- Fuel
- Hydraulics
- Pneumatics
- Ignition
- Generator input
- Fire bottle armed

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Controls and Indicators:

Function of the Electronic Engine Instrument Display (EEID)

Actual N1 white needle/text
Demanded by N1 (cyan)
100% N1 = fan speed 5,175 RPM
Continuous range 78% - 95.8%
GREEN within 1% of target
Caution 102.5% - 105%
Max 105.1%

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Controls and Indicators:

Function of the Electronic Engine Instrument Display (EEID)

EGT

Continuous 610-870 C
Caution 870-905
Warning 905 and above
Flight limit 930

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Controls and Indicators:

Function of the Electronic Engine Instrument Display (EEID)

100% N2 = 14,460 RPM
Continuous 89%-95%
Caution 105.1%-106%
Max 106.1%

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Controls and Indicators:

Function of the Electronic Engine Instrument Display (EEID)

Fuel Flow

0 - 15,000 PPH
During start, 300-680 prior to ignition, 900 after ignition
Idle, ~800 pph

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Controls and Indicators:

Function of the Fire/Overheat Detection and Extinguisher Systems

Logic Relay relationship between pulling fire switches and arming bottles

Controls and Indicators:

Function of the Electronic Engine Instrument Display (EEID)

Oil

Oil Gauge is 0-100 psi
Continuous 11-92 psi
Warning outside 11-92 psi
Temp gauge -50 - 200
Continuous -10 - 160
Warning 175 and above
Engine start caution: -50C to -10C

Controls and Indicators:

Function of the Fuel Control Systems

Throttles

Mechanically linked to MEC
Sets N2
Position sent to PMC to maintain N1

Controls and Indicators:

Function of the Fuel Control Systems

MEC

Sets N2 by metering fuel based on throttle position, altitude, temperature
Changes variable stators and variable bleed valves
Controls turbine clearance system
Inputs include:
- N1
- Fuel flow
- Fan inlet static pressure
- Compressor inlet temp
- Throttle position
- Torque motor current
- Compressor discharge pressure
- VSV/VBV feedback

Controls and Indicators:

Function of the Fuel Control Systems

PMC

Trims MEC
Inputs
- MEC
- Fan inlet static pressure
- Fan inlet temp
- Actual N1

Controls and Indicators:

Function of the Engine Ignition Control and Start System

Open starter valve allows low pressure bleed air to the starter
Can be manually opened
Starter auto-cutout begins 43-45% and takes 3-9 seconds

What are the 5 major sections of the Auxiliary Power Unit (APU)?

Centrifugal Compressor
Turbine
Combustion Chamber
Load Compressor
Variable inlet guide vanes

What are the 3 modes that you can run the Auxiliary Power Unit (APU)?

Normal
Gen only
EWO

What happens if you takeoff with the APUs running?

Squat switches start the Auto-Shutdown if you takeoff with the APU’s on

APU controls: Crew entry chute switch

Starts/Upgrades both APU's to NORM

APU controls: Where can you start the APUs from?

- APU control panel in the back - Crew entry chute - Pilot Start/Stop switches

APU controls: What does the EWO switch do?

- Starts both APUs in EWO mode - To downgrade, must be shutdown and restarted

APU controls: APU Aft Control Panel

- RPM gauge normally 100%-103% - RDY light at 100% - GEN only available from here - Surge Damper preload normally 1,600 psi - Start accumulator should be 3,000 (+/- 350) psi

APU controls: How much fuel does each mode use, and where does it draw its fuel from?

- GEN only:150 pph - NORM: 250 pph - EWO: 275 pph - Fuel from #2 main tank

Engine Operating Environment: Where are the engine danger areas for ground personnel?

25' in front and to the side 5' behind the inlet

Engine Operating Environment: Cold Weather Ops

- If less than -50C oil temp, heat oil, starter valve, MEC - Increasing oil pressure - Idle for 2 minutes prior to 70% N1 - JP-8 below -23C specifics: - minor torching may occur - Check MEC set for JP-8 - Max Motoring 25-27% - Monitor EGT - Abort start if no lightoff after 60 seconds

Engine Operating Environment: Hot Weather Ops

- Do as much of the preflight as possible before starting engines - Expect slower acceleration because of less dense air - APU ambient temp limits in -1

Engine Operating Environment: Volcanic Ash Ops

- Stay away! - Starter switches IGNITION, turn on bleed systems - Airspeed probably unreliable - Exit via shortest route, descend lowest thrust setting - Avoid rapid throttle movements - Record info required by -1 and report to maintenance