electronic engine control
DESCRIPTION
AvionicsTRANSCRIPT
© International Aero Engines Inc 2000
Electronic Engine ControlElectronic Engine Control
© International Aero Engines Inc 2000
Full Authority Digital Engine Full Authority Digital Engine Control SystemControl System
(F.A.D.E.C.)(F.A.D.E.C.)
© International Aero Engines Inc 2000
IntroductionIntroduction
The V2500 uses a Full Authority Digital
Engine Control (FADEC)
The FADEC comprises:
• Sensor inputs.
• Data inputs.
• The Electronic Engine Control (E.E.C.)
unit.
© International Aero Engines Inc 2000
Output devices include:
• Solenoids.
• Fuel Servo Operated Actuators.
• Pnuematic Servo Operated Devices.
• Dual Electrical Harness.
Introduction Introduction
© International Aero Engines Inc 2000
Engine Electronic ControlEngine Electronic Control
• The heart of the FADEC is the
Electronic Engine Control Unit (E.E.C.).
• Fan Case mounted unit.
• ‘Shielded’ and ‘grounded’ as protection
against Electro Magnetic Interference -
mainly lightning strikes.
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
EEC Mounting point
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
Engine Electronic ControlEngine Electronic Control(Features)(Features)
• Vibration Isolation Mountings.
• Lightning Strike Protection.
• Size - 15.9” x 20.1” x 4.4”
• Weight - 41 lbs.
• Two independent electronic channels.
• Two independent power supplies from dedicated generator.
• Built in handle to facilitate removal.
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Carrying Handle
© International Aero Engines Inc 2000
EEC DescriptionEEC Description
• 2 identical electronic circuits - identified as ‘Channel A & B’.
• Each channel receives identical signals and data from both the aircraft and engine systems such as:
• Air pressures, air temperatures, exhaust gas temperatures and rotor speeds.
© International Aero Engines Inc 2000
Electronic Engine ControlElectronic Engine Control
© International Aero Engines Inc 2000
EEC Description EEC Description
• The EEC also transmits engine performance data to the aircraft, this data is used in:
Thrust Management. Condition Monitoring Systems. Flight Deck Display.
• Each EEC channel can exercise full control of all engine functions.
© International Aero Engines Inc 2000
EEC Description EEC Description
• Control alternates automatically between Channel ‘A’ and ‘B’ for consecutive flights.
• The channel not in control being nominated as the ‘back-up’ channel.
• The two channels are physically separated within the EEC through a unique circuit mounting board system and exchange data through a data cross-link facility.
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
CHANNEL A OUTPUT DRIVER
© International Aero Engines Inc 2000
CHANNEL A OUTPUT DRIVER
CROSSLINK
CHANNEL B OUTPUT DRIVER
© International Aero Engines Inc 2000
Also known as P3
Also known as P4.9
© International Aero Engines Inc 2000
EEC ConnectionsEEC Connections
• Two identical, but separate harnesses provide input/output circuits between EEC and the relevant sensor/control actuator, and the aircraft interface.
• Harnesses are ‘keyed’.
• Pressure signals are sensed by transducers within the EEC, which are then converted into digital signals which are supplied independently to both channels.
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
EEC Connections EEC Connections
• The following pressures are sensed:• Pamb - Ambient air pressure (Fan Case
Sensor).• Pb - Burner pressure (Air Pressure - P3/T3
probe).• P2 - Fan Inlet pressure (P2/T2 probe).• P2.5 - LP Compressor (Booster stage) exit
pressure.• P5 (P4.9) - LP Turbine exhaust pressure
rake.• P12.5 - Fan Outlet pressure (Fan Rake).
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
P2/T2 Probe
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
P2.5 Pressure Rake Location
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
T2.5 Thermocouple Terminal
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
T2.5 Thermocouple Terminal
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
P3/T3 Probe
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
P3/T3 Probe
© International Aero Engines Inc 2000
EEC Connections EEC Connections
• There are eleven electrical connections which have a unique identification ‘J #’.
• Ten are numbered for the two EEC channels.
• One connection ‘J6’ is the ‘Data Entry Plug’ and must remain with the engine, as an engine part.
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
EEC Control FunctionsEEC Control Functions
• Engine Power Setting or ‘Engine Pressure Ratio’ (EPR).
• Acceleration and Deceleration times.
• Idle speed governing.
• Overspeed limit control (N1 and N2)
• Fuel flow.
• Variable Stator Vane System (VSV)
© International Aero Engines Inc 2000
EEC Control Functions EEC Control Functions
• Compressor Handling Bleed Valves (HP7 & HP10).
• LP Compressor (Booster Stage) Bleed Valve (BSBV).
• Turbine cooling (Stage 10 ‘Make-up’) air system.
• Active Clearance Control (ACC)
• Thrust Reverser
© International Aero Engines Inc 2000
EEC Control Functions EEC Control Functions
• Oil and Fuel Temperature Management.
• Automatic Engine Starting.
Note! The fuel cut-off command (Engine shut-down) is not controlled by the EEC. This is a command made directly by the ‘Flight Crew’.
© International Aero Engines Inc 2000
EEC Control Functions EEC Control Functions
Fault Monitoring.
• The EEC has extensive built-in ‘self test’
and ‘fault isolation’ logic.
• This logic operates continuously to
detect and isolate defects in the EEC.
© International Aero Engines Inc 2000
FADEC - General Arrangement
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
Engine Interface Unit (EIU) x2
• Supply aircraft data to EEC.
• Ensure engine to engine segregation.
• Select aircraft electrical supplies to the EEC.
• Supply data directly to other aircraft systems.
© International Aero Engines Inc 2000
EIU
28
28
28
CFDIUFCU
© International Aero Engines Inc 2000
Air Data Inertial Reference System
(ADIRS)
• Processes ‘pitot’ and ‘static’ pressure inputs.
• Supply air data to other aircraft systems,
including EEC and to the Display Management
Computers (DMC’s)
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
© International Aero Engines Inc 2000
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
Flight Warning Computer
(FWC) x2
• Process data and fault annunciation.
• Generate actions necessary for
associated fault.
© International Aero Engines Inc 2000
Display Management Computer
(DMC) x3
• Receive and process data from other
aircraft systems.
• Format and display the data on the six
display units on the flight deck.
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Upper ECAM Screen
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Lower ECAM Screen
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
Flight Management and Guidance Computer (FMGC) x2
• Flight Management, Navigation, Performance
Optimisation and Display Management.
• Flight Guidance, Auto Pilot and Autothrust
commands to the EEC.
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
© International Aero Engines Inc 2000
Additional interfaces with the EEC through the EIU are:
• Spoilers Elevators Computer (SEC).• Landing Gear Control Interface Unit (LGCIU).• Bleed Monitoring Computer (BMC).• Flight Control Unit (FCU).• Centralised Fault Display Interface Unit
(CFDIU).• Multipurpose Control and Display Unit
(MCDU).
Main EEC/Aircraft InterfacesMain EEC/Aircraft Interfaces
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Multipurpose Centralised Display Unit (MCDU)
© International Aero Engines Inc 2000
EEC - Data Entry PlugEEC - Data Entry Plug
Located on to ‘Junction 6’ of the EEC.
Provides the EEC with:
• Unique engine data to both Channel ‘A’
and ‘B’.
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Data Entry Plug Connection
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Data Entry Plug Connection
© International Aero Engines Inc 2000
Data supplied by the Data Entry Plug:
• EPR Modifier (Used to standardise power setting indication)
• Engine Rating (Selected from multiple rating options)
• Engine Serial Number.
EEC - Data Entry PlugEEC - Data Entry Plug
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Data Entry Plug
Data Entry Plug Lanyard
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Who put that up there?
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
Dummy C-Ducts
Bell Mouthed Intake
© International Aero Engines Inc 2000
EEC - Data Entry PlugEEC - Data Entry Plug
• Links coded data inputs through the
EEC by the use of shorting ‘jumper’
leads, which are used to select the plug
pins in a unique combination.
• Can be re-configured as a result of
‘Service Bulletins’ or after engine
overhaul when the EPR modifier code
may need to be changed.
© International Aero Engines Inc 2000
EEC Failures and RedundancyEEC Failures and Redundancy
Improved reliability is achieved
by utilising:
• Dual Sensors.
• Dual Feedback.
• Dual Control Channels.
© International Aero Engines Inc 2000
EEC Failures and RedundancyEEC Failures and Redundancy(Sensors)(Sensors)
• Dual Sensors are used to supply all
EEC inputs, with the exception of
pressures.
• Single pressure transducers within the
EEC provide signals to ‘A’ and ‘B’
channels.
© International Aero Engines Inc 2000
EEC Failures and RedundancyEEC Failures and Redundancy(Dual Control Channels)(Dual Control Channels)
EEC utilises identical software in each of it’s two channels.
• Each channel has an independent:Power supply.Processor.Programme memory and input/output functions.The channel ‘in control’ is decided by the logic,
selecting the healthiest and most capable of control.
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
Engine Electronic Control Unit
© International Aero Engines Inc 2000
EEC Failures and RedundancyEEC Failures and Redundancy(Dual Selectors)(Dual Selectors)
• Each channel normally uses it’s own input signals, but can use other channel input signal if it recognises faulty or suspect inputs.
• An output fault in one channel may cause a switchover to control from the other channel.
• If faults are experienced in ‘both’ channels, a pre-determined ‘hierarchy selects the more capable channel.
• Loss of both channels or electrical power, the systems are designed to go to ‘fail-safe’ conditions.
© International Aero Engines Inc 2000
5
© International Aero Engines Inc 2000
5
© International Aero Engines Inc 2000
EEC SystemEEC System
Failsafe PositionFailsafe Position• Minimum Fuel Flow Minimum Fuel Flow
Position.Position.• Last Commanded Last Commanded
Position.Position.
• Normal Fuel MeteringNormal Fuel Metering
ComponentFuel Metering Valve Torque
Motor.
Fuel Shut-Off Valve.
Overspeed Valve Solenoid.
© International Aero Engines Inc 2000
Failsafe PositionFailsafe Position
• Valves OpenValves Open
• Valve OpenValve Open
• Valve OpenValve Open
Component
7th Stage Bleed Valves
10th Stage Bleed Valves
LP Compressor (2.5) Bleed Actuator
EEC SystemEEC System
© International Aero Engines Inc 2000
Failsafe PositionFailsafe Position
• Valve Partially Open (44%)Valve Partially Open (44%)
• Valve ClosedValve Closed
Component
Active Clearance Control Unit. (ACC)
Low Pressure ACC
High Pressure ACC
EEC SystemEEC System
© International Aero Engines Inc 2000
Failsafe PositionFailsafe Position
• Vanes OpenVanes Open
• Valve OpenValve Open
• Valve OpenValve Open
Component
Stator Vane Actuator.
Air/Oil Cooler Control Valve
Actuator.
Stage 10 Turbine Cooling
‘Make-up’ Air Valve.
EEC SystemEEC System
© International Aero Engines Inc 2000
• Failsafe PositionFailsafe Position
• Solenoid De-energised Solenoid De-energised (Mode 4 or 5)(Mode 4 or 5)
• Valve Closed - No return to Valve Closed - No return to tank (Mode 3 or 5)tank (Mode 3 or 5)
Component Fuel Diverter Return
to Tank Valve.
Fuel Diverter Valve.
Fuel Return to Tank Valve.
EEC SystemEEC System
© International Aero Engines Inc 2000
Failsafe PositionFailsafe Position
• Ignition ‘On’Ignition ‘On’
• Heater ‘Off’Heater ‘Off’
ComponentP2/T2 Relay Box
Ignition Relays
Probe Heater Relays
EEC SystemEEC System
© International Aero Engines Inc 2000
Failsafe PositionFailsafe Position
• Reverser ‘Stowed’.Reverser ‘Stowed’.
• Valve ‘Closed’.Valve ‘Closed’.
Component
Thrust Reverser
Control Unit.
Starter Air Valve
EEC SystemEEC System
© International Aero Engines Inc 2000
EEC Power SuppliesEEC Power Supplies
• The power supplies are normally
provided by a ‘Dedicated Alternator’
mounted on the ‘External Gearbox’.
© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000© International Aero Engines Inc 2000
© International Aero Engines Inc 2000
EEC Power Supplies:EEC Power Supplies:(Dedicated Alternator)(Dedicated Alternator)
• ‘Permanent Magnet’ Alternator.
• 2 sets of independent stator windings.
• Provides 2 independent 3 phase Alternating Current (AC) supplies.
• AC supply ‘rectified’ to 28 volts Direct Current (DC) within the EEC.
• Also provides the N2 (HP Rotor) speed to the EEC.
© International Aero Engines Inc 2000
STATOR
ROTOR
© International Aero Engines Inc 2000
EEC also utilises aircraft power
supplies to operate some engine
systems.
• 115 volts AC 400 hz supply for:
Engine Ignition System.
P2/T2 Probe ‘Anti-icing’ heater.
EEC Power SuppliesEEC Power Supplies
© International Aero Engines Inc 2000
28 volts DC is required for some specific
functions, which include:
• Thrust Reverser.
• Fuel ‘on/off’.
• Ground Test power for EEC
maintenance.
EEC Power SuppliesEEC Power Supplies
© International Aero Engines Inc 2000
• Should the Dedicated Alternator fail, the EEC will be supplied with 28 volts DC from the aircraft Bus-bars.
• 28 volts DC from the same source will be used by the EEC during the start sequence until the Dedicated Alternator comes ‘on-line’ at approximately 10% N2.
• Switching of the power supply source is automatically controlled by the EEC.
EEC Power SuppliesEEC Power Supplies