Liberty-XL2-FADEC(ppt)

FADECFADECFull Authority Full Authority

Digital Engine ControlDigital Engine Control

FADEC OverviewFADEC Overview

Full Authority Digital Engine ControlFull Authority Digital Engine Control

System continuously monitors and System continuously monitors and controls ignition timing, fuel injection controls ignition timing, fuel injection timing, and fuel-to-air ratio mixturetiming, and fuel-to-air ratio mixture

Therefore, a FADEC equipped engine Therefore, a FADEC equipped engine does not require magnetos and eliminates does not require magnetos and eliminates the need for manual fuel/air mixture the need for manual fuel/air mixture control.control.

Basic components of FADECBasic components of FADEC

Two Electronic Control Units (ECUs)Two Electronic Control Units (ECUs) Health Status Annunciator (HSA)Health Status Annunciator (HSA) FADEC Sensor setFADEC Sensor set

(1) Speed Sensor Assembly (SSA)(1) Speed Sensor Assembly (SSA)(4) Cylinder Head Temperature (CHT)(4) Cylinder Head Temperature (CHT)(4) Exhaust Gas Temperature (EGT)(4) Exhaust Gas Temperature (EGT)(2) Manifold Air Pressure (MAP)(2) Manifold Air Pressure (MAP)(2) Manifold Air Temperature (MAT)(2) Manifold Air Temperature (MAT)(2) Fuel Pressure Sensors (2) Fuel Pressure Sensors (1) Throttle Position Switch (WOT)(1) Throttle Position Switch (WOT)

Low Voltage HarnessLow Voltage HarnessFigures 3-2 and 3-1Figures 3-2 and 3-1 in FADEC manual in FADEC manual

Connects all essential components of Connects all essential components of FADEC FADEC

Fuel Injector Coils and all sensors (except Fuel Injector Coils and all sensors (except SSA, Fuel Pressure, Manifold Pressure) SSA, Fuel Pressure, Manifold Pressure) are hardwired to the low voltage harnessare hardwired to the low voltage harness

All information from sensors will flow to the All information from sensors will flow to the Electronic Control Units for data Electronic Control Units for data processing and analysisprocessing and analysis

Electronic Control Unit (ECU)Electronic Control Unit (ECU)3-7 to 3-9 in FADEC manual3-7 to 3-9 in FADEC manual

““Brain” of the Engine Control SystemBrain” of the Engine Control SystemECU divided into an upper and lower ECU divided into an upper and lower portionportion Lower portion contains the Lower portion contains the Electronic Circuit Board that Electronic Circuit Board that processes all dataprocesses all data Upper portion contains the Upper portion contains the ignition coils for the spark ignition coils for the spark plugs (each ECU has (4) coils)plugs (each ECU has (4) coils)

ECU cont’dECU cont’d

The electronic circuit board (lower portion) of The electronic circuit board (lower portion) of each ECU contains (2) independent each ECU contains (2) independent microprocessor controllers which serve as microprocessor controllers which serve as control channels control channels

(1) control channel is assigned to operate a (1) control channel is assigned to operate a single engine cylinder (thus one ECU per pair of single engine cylinder (thus one ECU per pair of cylinders)cylinders)

ECU #1 controls opposing cylinders 1& 2…ECU ECU #1 controls opposing cylinders 1& 2…ECU #2 controls opposing cylinders 3 & 4#2 controls opposing cylinders 3 & 4

ECU cont’dECU cont’d

Control channel will receive the sensor Control channel will receive the sensor inputs and monitor any changesinputs and monitor any changes

Control channel will use these inputs to Control channel will use these inputs to precisely trim the fuel to air ratio going into precisely trim the fuel to air ratio going into each cylindereach cylinder

Therefore, the control channels allow each Therefore, the control channels allow each cylinder to be individually leaned or cylinder to be individually leaned or enrichedenriched

ECU cont’dECU cont’d

If one control channel fails within an ECU the other If one control channel fails within an ECU the other control channel can operate it’s assigned cylinder as well control channel can operate it’s assigned cylinder as well as the opposing cylinder as backup control for fuel as the opposing cylinder as backup control for fuel injection and ignition timinginjection and ignition timingAll critical sensors are redundant with one sensor from All critical sensors are redundant with one sensor from each type connected to a control channel in different each type connected to a control channel in different ECUsECUsSynthetic software default values are also used should Synthetic software default values are also used should both sensors of a redundant pair fail…therefore, FADEC both sensors of a redundant pair fail…therefore, FADEC will always have a value to work off of so it can inject an will always have a value to work off of so it can inject an average amount of fuel to the cylinderaverage amount of fuel to the cylinder

Health Status Annunciator (HSA)Health Status Annunciator (HSA)

HSA cont’dHSA cont’d

Consists of (5) lights on panel and WOTConsists of (5) lights on panel and WOT

HSA provides information regarding the HSA provides information regarding the status of the FADEC systemstatus of the FADEC system

We have the 2-light system display We have the 2-light system display referenced in the manual plus additional referenced in the manual plus additional indicators as seen on the HSA indicators as seen on the HSA

HSA will not give you a warning or caution HSA will not give you a warning or caution light for OIL temp/pressure or ALT FAILlight for OIL temp/pressure or ALT FAIL

HSA lightsHSA lights

FADEC WARNFADEC WARN: Engine Failure may be : Engine Failure may be imminent, more than (1) cylinder is affected…imminent, more than (1) cylinder is affected…land ASAPland ASAP

FADEC CAUTIONFADEC CAUTION: 99.99% of installed : 99.99% of installed components are working. No immediate action components are working. No immediate action is req’d. Most common example is a bad EGT is req’d. Most common example is a bad EGT sensor…all sensors are redundantsensor…all sensors are redundant

ANYTIME YOU GET A WARNING OR ANYTIME YOU GET A WARNING OR CAUTION REFER TO VM1000…this is a CAUTION REFER TO VM1000…this is a window into what FADEC seeswindow into what FADEC sees

HSA lights cont’dHSA lights cont’d

PPWR FAILPPWR FAIL: Primary Battery is not being : Primary Battery is not being charged, will be accompanied by EBAT charged, will be accompanied by EBAT FAIL…you will start draining both batteries FAIL…you will start draining both batteries and have at least 60 minutes to land. and have at least 60 minutes to land. Your secondary battery will only power Your secondary battery will only power FADEC, AI, and Turn CoordinatorFADEC, AI, and Turn CoordinatorEBAT FAILEBAT FAIL: Backup Battery not being : Backup Battery not being charged, everything can run from Primary charged, everything can run from Primary Power Source/Battery Power Source/Battery

HSA Lights cont’dHSA Lights cont’d

FUEL PUMPFUEL PUMP: illuminates when Fuel Boost Pump : illuminates when Fuel Boost Pump Mode Switch is in ON or OFF. If this light is Mode Switch is in ON or OFF. If this light is illuminated it means that you are manually illuminated it means that you are manually controlling the fuel pump or that the fuel controlling the fuel pump or that the fuel pressure is out of the 20-40 psi range. pressure is out of the 20-40 psi range. Illuminates for electric driven fuel pump as well Illuminates for electric driven fuel pump as well as engine driven pumpas engine driven pumpWOTWOT: below HSA panel. Illuminates when : below HSA panel. Illuminates when Throttle Position Switch (TPS) is contacted (full Throttle Position Switch (TPS) is contacted (full throttle), signal sent to ECU that max power is throttle), signal sent to ECU that max power is req’d which causes FADEC to set fuel to air ratio req’d which causes FADEC to set fuel to air ratio for Best Power for Best Power

FADEC Ignition SystemFADEC Ignition System

Consists of high voltage harness and Consists of high voltage harness and spark plugs (2 plugs per cylinder)spark plugs (2 plugs per cylinder)Employs a waste spark ignition system- Employs a waste spark ignition system- plugs fire once on compression and once plugs fire once on compression and once on exhaust... this keeps plugs cleanon exhaust... this keeps plugs cleanECU#1 fires top and bottom spark plugs ECU#1 fires top and bottom spark plugs for cylinders 1 & 2for cylinders 1 & 2ECU#2 fires top and bottom spark plugs ECU#2 fires top and bottom spark plugs for cylinders 3 & 4for cylinders 3 & 4

Power SuppliesPower Supplies

PPrimary rimary PPower ower SSource (ource (PPSPPS)-)- 14v 60amp alternator and 12v 25Ah Lead Acid type 14v 60amp alternator and 12v 25Ah Lead Acid type

battery (located aft baggage compartment)battery (located aft baggage compartment)

SSecondary econdary PPower ower SSource (ource (SPSSPS)-)- 12v 7Ah Lead Acid type battery12v 7Ah Lead Acid type battery

PPS and SPS have separate set of breakers PPS and SPS have separate set of breakers and the power supply circuits are separatedand the power supply circuits are separatedBattery condition monitor will illuminate HSA with Battery condition monitor will illuminate HSA with PPWR FAILPPWR FAIL or or EBAT FAILEBAT FAIL to alert pilot of to alert pilot of possible power supply losspossible power supply loss

Power Supplies cont’dPower Supplies cont’d

FADEC operates off of primary power source FADEC operates off of primary power source with alternator indefinitely with alternator indefinitely Alternator fails- FADEC will use primary battery until Alternator fails- FADEC will use primary battery until

12v then will cycle between using PPS and SPS 12v then will cycle between using PPS and SPS every volt (FADEC always looking for best power every volt (FADEC always looking for best power source) until batteries are drainedsource) until batteries are drained

FADEC can operate on SPS (aka backup or FADEC can operate on SPS (aka backup or emergency battery) for at least 1 houremergency battery) for at least 1 hour SPS is only to supply power to FADEC (AI and TC will SPS is only to supply power to FADEC (AI and TC will

also work) and can not be used for startingalso work) and can not be used for starting

FADEC System RedundancyFADEC System Redundancy

Power Supplies (PPS and SPS) Power Supplies (PPS and SPS) If a control channel (CC) has a fault, the If a control channel (CC) has a fault, the other CC within the same ECU is capable other CC within the same ECU is capable of operating its assigned cylinder as well of operating its assigned cylinder as well as the other cylinder experiencing the faultas the other cylinder experiencing the faultAll sensors are redundant with one sensor All sensors are redundant with one sensor from each pair connected to channels in from each pair connected to channels in different ECUs. Synthetic software different ECUs. Synthetic software defaults are used in case of sensor failure defaults are used in case of sensor failure

REVIEWREVIEW

FADEC utilize a set of redundant sensors linked FADEC utilize a set of redundant sensors linked to the respective ECUto the respective ECUECU then uses data to analyze and control the ECU then uses data to analyze and control the ignition timing, fuel injection timing and fuel to air ignition timing, fuel injection timing and fuel to air ratio for each cylinderratio for each cylinderFADEC is powered by 3 sources: alternator, FADEC is powered by 3 sources: alternator, primary battery, emergency battery…FADEC primary battery, emergency battery…FADEC needs only 1 power source to operateneeds only 1 power source to operateReduces a pilot’s “busy work” Reduces a pilot’s “busy work” 15% more fuel efficiency than correct and 15% more fuel efficiency than correct and accurate conventional mixture control accurate conventional mixture control

Low Voltage HarnessLow Voltage Harness