The PW1100G engine is an axial flow, dual-rotor, geared fan, variable stator, ultra high bypass ratio (The

bypass
ratio of this engine is 12:1.) power plant. The geared turbo fan engine reduces fuel consumption, air pollution and
noise. Each engine comes with a Data Storage Unit (DSU) which is connected onto the Electronic Engine Control
(EEC). It provides engine parameters,
thus the possibility of changing the thrust rating.

The power plant installation includes the engine, the engine inlet cowl, the fan cowls, the thrust reverser assemblies
and the exhaust nozzle and center body. The forward engine mount is located on the Compressor Intermediate case.
The rear engine mount is located on the Turbine Exhaust Case.

The PW1100G engine assembly modules are:

- Fan rotor - Fan and Intermediate Case - Fan Drive Gear System (FDGS) - Low Pressure Compressor (LPC)
- Compressor Intermediate Case (CIC) - High Pressure Compressor (HPC) - Gearboxes under engine core
- Diffuser and combustor - High Pressure Turbine (HPT) - Turbine Intermediate Case (TIC)
- Low Pressure Turbine (LPT) - Turbine Exhaust Case (TEC).

The speed of the LP rotor is indicated on the ECAM as N1. The fan supplies most of the engine thrust. The air
produced by the fan is known as secondary airflow or bypass airflow. To improve the propulsive efficiency and fuel
consumption, the FDGS reduces the fan speed thanks to reduction gear mechanism. The 3-stage Low Pressure (LP)
compressor supplies air to the engine core. This is primary airflow. The LP compressor rotates at the same speed as
the 3 stage LP turbine. The High Pressure (HP) rotor is made up of 8 stage HP compressor driven by two stage HP
turbine. The speed of the HP rotor is indicated on the ECAM as N2. The annular combustion chamber is installed
between the HP compressor and HP turbine. It has ports for 18 fuel nozzles and 2 igniter plugs (ONLY 1 EXCITER
BOX).

TOTAL 7 BEARINGS :- 2 AT FDGS (1 & 1.5), 1 LP FRONT 2 LP AFT, 1 HP FRONT 1 HP REAR. BUT WILL
BE COUNTED AS 6. (5 IN CFM)

The accessory gearbox is installed under the core engine and is driven by the HP rotor through the Angle gearbox.

The Propulsion Control System (PCS) regroups the following subsystems:

- The FADEC system consists of an Electronic Engine Control (EEC) and a Prognostic Health Monitoring Unit
(PHMU),
- The Engine Interface Unit (EIU).

The EEC controls the operation of the following:

- Engine control for thrust setting in Manual and Auto thrust Modes, - Thrust Control Malfunction protection,
- Engine airflow control, - Combustor fuel metering valve, - Control and monitoring sensing,
- Ignition and starting systems, - Command and monitoring of the thrust reverser system,
- Fault detection, isolation, annunciation and transmission to the A/C(BITE).

The PHMU interfaces with the EEC. It monitors the Engine vibrations and the Oil debris.

The main functions of the EIU are:

- To concentrate data from cockpit panels and different aircraft systems to the associated EEC on each engine,
- To ensure the segregation of the two engines,
- To give to the airframe the necessary logic and information from engine and to other systems (APU, ECS, Bleed
Air, Maintenance),
- To give to the FADEC system some necessary logic and information from systems (example: flight/ground
status).

The Fan Cowl latches of the A320 NEO are monitored by proximity switches which send their position signals to
the EIU. The EIU transfers signals to the FWC for associated cockpit warnings based on specific logic conditions.

The thrust reverser system comprises of 2 translating sleeves, 10 blocker doors with cascade vanes per engine. The
SEC computers authorize unlocking of Tertiary Locks. Reverse thrust is only available on the ground.
The oil system comprises of an Oil tank, oil pumps located within the Lubrication and Scavenge Oil Pump unit
(LSOP), Oil Control Module (OCM), filters and heat exchangers.
FOR TEST :- MCDU-CFDIU-EIU-EEC
The preservation procedures protect the engine against corrosion, liquid and debris entering the engine, and
atmospheric conditions during period of inactivity.

The thrust reverser system operated from the cockpit consists of 2 hydraulically operated translating sleeves.
When the translating sleeve moves aft during deployment, it lifts blocker doors that redirect the engine fan airflow.
On the A320NEO PW1100G, the HCU is made of an Isolation Control Unit (ICU) and a Directional Control Unit
(DCU) attached together. The Hydraulic Control Unit (HCU) is installed on the pylon.

The drains system provides a controlled leak path exit to the 6 o'clock position of the nacelle for hydraulic, oil and
fuel systems. The drains system is comprised of the upper pylon drains hoses, lower drains through the nacelle
bifurcation and the scupper drains assembly attached to the fan case providing drainage for the oil reservoir.
At the lower bifurcation, lateral, core and aft support for the 10 drains tubes is provided through the mid-clamp
support attached to the Nacelle Anti-Icing (NAI) flag and through the latch beam seal interface.

The inlet cowl is composed of an inner barrel, outer barrel, forward bulkhead, aft bulkhead and a nose lip. The inner
and outer barrels are made of composite material. The forward and aft bulkhead provides support and rigidity to the
structure. The inlet lip is made of a single piece aluminium alloy for engine anti-ice purpose. For removal and
installation, the inlet cowl is attached to the engine at the attach ring with 40 bolts. The main function of the inlet
cowl is to guide the airflow into the engine inlet and to permit an aerodynamic airflow over the outer surface of the
engine. The outer barrel has an impregnated copper screen layer for protection against lightning strike.

Aerodynamic strakes are mounted on the fan cowls to improve aircraft performance during maneuvers. The fan
cowl door rests on 4 axial locators, when closed.

The thrust reverser cowl doors (or "C" Ducts) are in two halves. Each half includes one translating sleeves, two
actuators, five blockers doors and cascades. The assembly is latched along the bottom centerline by seven latches.

The exhaust nozzle is formed by the center bodies and nozzle assembly. The annular passage between the exhaust
nozzles and the center bodies provide a smooth exit of the exhaust gas flow. The fire seal fingers (turkey feathers) at
the top of the exhaust nozzle prevents any flame from entering the core compartment area in the event of fire. The
center body also accommodates the drain outlet to expel hazardous fluids and vapors. These drains are located at the
6 o' clock position on the forward and aft center bodies.

The forward mount assembly bears the engine thrust, vertical and lateral loads. The thrust link assemblies attached
to the forward mount take the lateral loads. They are attached to the forward mount through a balance beam. They
are attached to the Compressor Intermediate Case at 09:30 and 02:30 position. The aft mount assembly bears the
engine vertical and radial loads.

The fan rotor comprises of the fan drive shaft, inlet cone and 20 wide chord fan blades. The fan blades are made of
aluminum alloy honeycomb structure and reinforced by Titanium leading edges. The fan rotational speeds being
lower helps in reducing rotational loads and bird strike fan damage. The fan rotates in a clockwise direction as
viewed from the aft lookingforward.The inlet cone is made of composite material and is anti-iced with a continuous
airflow from of the 2.5 compressor stage. The Fan case is made of single piece composite material (Kevlar). It holds
the outer edge of the Fan Exit Guide Vanes (FEGV).The inner walls behind the fan blade area are provided with
acoustic liners for noise reduction. A rubberized strip along the fan blade area helps in minimizing the gap and
prevents contact between the blades and the case.

The FDGS is a reduction gear mechanism which comprises of a central sun gear and five planetary gears arranged
like a star. It helps in reducing the fan rotating speed and permits the LPC to rotate at a higher speed. This helps in
improving engine performance and efficiency. The ratio of the LPC speed: fan speed is approximately 3:1. The LPC
rotates in the opposite direction of the fan rotor. The FIC supports the FDGS and the bearings No. 1, 1.5 and 2. It
also supports the inner edge of the Fan Exit Guide Vanes (FEGVs) and the support fairings. It houses a single stage
Variable Inlet Guide Vanes (VIGVs) which direct the air to the LP Compressor at the correct angle. The VIGV's are
controlled by the EEC.
The LPC houses the 2.5 stage bleed valve at the rear which releases the air during engine operation to prevent surge
and stall conditions. It rotates counter clockwise viewed from the rear. The CIC transmits the engine core airflow
from the LPC to the HPC. It supports the bearing No.3 and also provides the ports for the 2.5 stage bleed air flow to
join the fan air flow.

The HPC comprises of eight stages axial flow compressor and the shaft which are driven by the HP turbine. A
single stage of Variable Inlet Guide Vane (VIGV) and the first three stages of Variable Stator Vanes (VSVs) of the
HPC stators ensure a smooth entry of air to the HPC. Each stage of the variable stators is connected by the unison
rings. The VIGVs and VSV stator vanes are operated by the primary and secondary actuators controlled by the
EEC.The HP Compressor supplies air from Stage 3 and stage 8 to the aircraft systems.

The annular combustion chamber houses 18 fuel nozzles (6 Simplex and 12 Duplex). Integrated in the HPT
assembly is the TIC which directs the HP Turbine airflow to align with the LP Turbine. It supports the n°4
bearing. The TEC supports the rear roller bearings 5 and 6. It houses four Exhaust Gas Turbine (EGT)
thermocouples.

The engine bearings provide reduce rolling friction and supports the rotor axially and radially within the structure.
There are five bearing compartments containing a total of seven bearing.
No. 1 and 1.5 are tapered roller bearing and are used to support the fan rotor and FDGS.
No. 2 and 3 are ball bearings and support the front part of LP and HP rotor respectively.
No. 4 is roller bearing and support the rear of N2.
No.5 and 6 are roller bearing and support the rear of N1 rotor.
Bearing compartments are sealed using carbon seals to prevent oil leakage.
There are 4 bearing compartments, (1, 1.5 & 2) (3) (4) (5 & 6)

FUEL SYSTEM:-
The boost pump sends LP fuel from the engine fuel supply line to the IDG FOHE. Fuel flow is used to cool down
the IDG oil through the IDG FOHE and the engine oil through the engine FOHE. In turn, fuel is heatedand de-iced.
Fuel from the engine FOHE is then sent to the fuel filter.The Fuel Return-To-Tank (FRTT) module contains the fuel
Return Valve (FRV) and the FRTT Temperature sensor. The FRV controls fuel to flow back to the aircraft tanks
from downstream of the IDG FOHE and before it enters the engine FOHE as part of the fuel heat management
system. The FRV is controlled by the Electronic Engine Control (EEC) depending on the fuel temperature.
RTT valve is controlled by EEC based on a/c altitude, ambient temperature and fuel flow. The valve opens when the
fuel temperature reached certain valve, opening the valve helps to cool IDG oil since more fuel flow to disspate the
heat.
The IFPC is an electronically controlled unit which integrates the fuel metering components and the fuel pumps in a
single unit to limit the space and the number of external tubes required for the system. The IFPC uses dual coil
torque motors and solenoids to control hydro-mechanical valves in relation to the fuel flow. The Main Gearbox
(MGB) turns the IFPC input shaft which drives the fuel pump boost-stage, the main fuel pump and servo pump.
The heated fuel from the engine FOHE is directed through the fuel filter. The filter element is a disposable filter
located in a housing attached on the fuel manifold. The filter is monitored by a differential pressure transmitter. The
filter housing is fitted with a bypass valve in case of filter element clogging. The filter element is a disposable 25
micron filter. The fuel exits the fuel filter and flows to the inlet port of the main fuel pump. The main fuel pump is a
single-stage gear pump, which increases the fuel pressure and sends the pressurized fuel to the Fuel Metering Valve
(FMV). The EEC controls a dual Torque Motor (TM) which positions the FMV in the desired position. The close
loop monitoring is ensured by the EEC using the valve LVDT feedback signals. The fuel from the FMV is directed
to the High Pressure Shut-Off Valve (HPSOV). The fuel pressure at the back side of the HPSOV is controlled by
the Thrust Control Malfunction (TCM)/Overspeed TM and allows the valve to open or close. Inside the IFPC, the
fuel from the main pump is directed to the FMV and to the Pressure Regulating Valve (PRV). The purpose of the
PRV is to maintain a constant fuel pressure drop across the FMV to ensure the correct fuel flow and acceleration for
the engine. The TCM/Overspeed TM controls the fuel pressure to the back side of the PRV to modulate fuel flow
between the FMV and the Bypass Directional Control Valve (BDCV). Pressurized fuel that passes through the PRV
is directed to the BDCV. The BDCV directs fuel by-passed by the PRV to the engine FOHE at low engine power or
when the fuel temperature is low to help in maintaining the engine oil and fuel within operating limits. At high
power, the BDCV returns the recirculation flow downstream of the FOHE.
The EEC controls the dual TCM/Overspeed TM for HPSOV positioning. It monitors the valve fully closed position
with the two proximity switches.
The EEC also controls the FMV position via a dual channel Torque Motor (TM).A dual channel Linear Variable
Differential Transducer (LVDT) provides the FMV position to the EEC.
For the air system, the EEC controls the fuel-operated actuators with dual channel TMs and it monitors their
position thanks to LVDT position feedbacks.
The metered fuel from the FMV crosses the HPSOV and flows to the fuel flow transmitter. The fuel flow
transmitter sends the fuel flow rate to the EEC channel A and directs fuel to the Flow Divider Valve (FDV).
The EEC commands the FDV opening during starting to improve fuel atomization. During engine start, the FDV
sends most of fuel to the primary manifold. Above idle, the FDV evenly divides metered fuel flow between the
primary and secondary fuel manifolds. At shutdown, the FDV is spring loaded closed to allow primary and
secondary manifold drainage. The FDV is fitted with a metal screen strainer that can be bypassed in case of
blockage. There are 18 fuel nozzles mounted to the outer diffuser case. All the nozzles atomize fuel inside the
combustor. Twelve of them are duplex nozzles featuring both a primary and a secondary fuel flow paths while six
others are simplex nozzles providing only a secondary fuel flow path.
The servo pump housed in the IFPC is a gear-stage pump which sends pressurized fuel to a wash filter. Fine filtered,
pressurized fuel from the wash filter is supplied to the engine air system actuators where it is used as servo and
muscle pressure to position the actuator pistons.
These actuators are:
- the Low Pressure Compressor (LPC) Stator Vane Actuator (SVA),
- the LPC (2.5) Bleed Valve Actuator (BVA),
- the turbine Active Case Cooling (ACC) valve,
- and the High-Pressure Compressor (HPC) SVAs (primary and secondary).
The fuel from the actuators is filtered again before it returns back to main pump and servo pump inlet. The Servo
Minimum Pressure and Pump Sharing Valve is a spring loaded valve that provides the five air system actuators with
main pump fuel pressure when servo pump fuel pressure is not enough during start.
At engine shutdown, residual fuel in the manifolds downstream of the FDV is drained back through the FDV to an
ecology collector tank. The collected fuel remains in the ecology collector tank until the next engine start when the
fuel is drawn back into the fuel system. During shutdown, the fuel pressure from the IFPC is reduced and the FDV
closes to prevent fuel from entering the combustor and to drain any fuel remaining in both the primary and
secondary fuel lines to the ecology collector tank. The ecology collector tank has enough space to receive fuel from
a single engine shutdown. The tank has an inlet float valve which closes when the tank has reached its maximum
capacity. This prevents the tank from overfilling and spilling fuel out following an aborted start. At next engine start
up, the ejector pump draws the fuel from the ecology collector tank back to the IFPC boost pump. The tank has an
outlet float valve which closes when the tank has reached its minimum capacity and a check valve to avoid fuel
transfer from the suction line.
INITIAL STARTING:- During starting, the servo pump fuel pressure is not enough to control the air system
actuators and to close the Servo Minimum Pressure and Pump Sharing Valve. In this position, the Servo Minimum
Pressure and Pump Sharing Valve directs a portion of pressurized fuel from the main pump to the five actuators.
The other portion of fuel from the main pump is sent to the PRV and to the FMV. The PRV opens partly and directs
the excess of fuel flow to the BDCV which is spring loaded to send it to the engine FOHE. The EEC opens the
FMV and let the fuel to flow to the HPSOV which also opens and sends fuel to the fuel flow transmitter. The
pressurized fuel opens the FDV. The FDV partly opens and sends most of fuel to the primary fuel nozzles.
As the pumps rotation speed increases with the engine acceleration, the fuel pressure also increases. The FMV
opens more and as a consequence the fuel pressure pushes the BDCV out of its rest position to direct the excess fuel
flow to the fuel filter. The FDV also opens more and evenly divides metered fuel flow between the primary and
secondary fuel nozzles. In parallel, the fuel pressure from the servo pump increases and pushes the Servo Minimum
Pressure and Pump Sharing Valve, segregating the burn flow from the servo fuel.
NORMAL SHUTDOWN:- During a normal engine shutdown, the Master Lever controls the LPSOV to close and
sends a shutdown signal to the EEC. As a consequence, the EEC controls the TCM/overspeed TM that directs fuel
pressure to the back side of the HPSOV to close it and stop the fuel flow to the engine. In the same time, the PRV is
controlled fully open to bypass the main pump fuel flow away from the FMV to the FOHE. In turn when the related
fuel pressure drops, the FDV closes to let the remaining fuel in the nozzle manifolds to drain in the ecology drain
tank, and the Servo Minimum Pressure and Pump Sharing Valve reopens. After the HPSOV is confirmed closed by
the proximity switches, the EEC tests the FMV via its TM then closes it.
ABNORMAL SHUTDOWN :- The abnormal shutdown is initiated in case of an over speed (N1 or N2), shaft shear
(fan, LP or HP) or Thrust Control Malfunction (TCM) event detected on ground. In such case, the TCM/over speed
TM directs fuel pressure to the back side of the HPSOV and of the PRV. This causes the PRV to open and stop fuel
flow to the FMV, allowing rapid closure of the HPSOV and rapid engine shutdown. Fuel flow through the PRV is
directed to the BDCV and then to the engine FOHE. This shutoff method is independent from the FMV control.

The Fuel Filter Differential Pressure (FFDP) sensor measures the differential pressure across the fuel filter. This
helps to detect if the filter is partially or totally clogged. According to the received value, the EEC will generate
various warnings on the EWD: ENG X FUEL FILTER DEGRAD or ENG X FUEL FILTER CLOG or ENG X
FUEL SENSOR FAULT and on the SD: CLOG. The IDG Fuel-Oil Heat Exchanger (FOHE) differential pressure
sensor is used to sense the differential pressure on the fuel side of the FOHE and send a signal to the EEC in case of
clogging detection. According to the status, the EEC will generate various warnings on the EWD: ENG X HEAT
EXCHANGR CLOG or ENG X FUEL SENSOR FAULT. For monitoring and Thermal Management System
control by the EEC, the fuel temperature is sensed by two dual channel temperature sensors. The fuel temperature
sensor is used for the control of the heat exchaexchangers (Fuel/Oil Heat Exchanger Bypass Valve (FOHEBV)) and
BDCV. The Fuel Return To Tank (FRTT) temperature sensor is used for the RTTV control. The engine fuel
temperature is not directly displayed in the cockpit but, according to the status, the EEC will generate various
warnings on the EWD: ENG X HOT FUEL or ENG X FUEL HEAT SYS or ENG X HEAT SYS DEGRADED or
ENG X HEAT SYS FAULT.

Both EEC & PHMU are vibration-isolated units, which are cooled by natural convection.
The FADEC controls the engine parameters displayed in the cockpit. The primary parameters (N1, N2, Exhaust Gas
Temperature (EGT) andFuel Flow (FF)) are sent by the EEC to the ECAM through DisplayManagement Computers
(DMCs)
If the aircraft is on ground and extend the slats the engine will stay at minimum idle but in flight it will go to
approach idle. The idle can also be modulated up to approach idle depending on: Air conditioning demand, wing
anti-ice demand, engine anti-ice demand and oil temperature (for Integrated Drive Generator (IDG) cooling).
The FADEC ensures engine integrity protection. It provides over speed protection for N1 and N2 or rotor shaft
shear by driving to close the Thrust Control Malfunction (TCM)/Over speed torque motor in the Integrated Fuel
Pump and Control (IFPC). Shaft shear detection logic is only active at high power settings. It ensures overheat
protection by monitoring EGT, nacelle and EEC temperature.
Five electrical connectors are used in each channel module to connect wiring from the engine, aircraft and nacelle.
The EEC also has a connector to test the unit and a connector for the Data Storage Unit (DSU). The DSU is a data
memory plug attached to the engine case bracket by a lanyard and connected on the EEC channel A for engine
identification and rating, engine trim data storage and detected failure storage.
The PHMU is a single channel component with internal software that performs the following engine health
monitoring functions:
- Vibration analysis, - Engine trim balance solution computation, - Oil Debris Monitoring (ODM),
- Auxiliary Oil Pressure (AOP) signal conversion.
It uses data provided by several engine sensors and by the EEC and sends back the computed data to the EEC
through CAN buses. Two connectors are used for the data exchange.

When fully operational, the EEC starts and operates in an Active-Standby mode. Under this control scheme, only
one channel of the EEC has full authority over all engine functions and is identified as the preferred channel. The
preferred channel is alternated upon every engine shutdown for the next engine start. If a feedback fault is detected
in the preferred channel, the data is retrieved from the standby channel via the crosstalk data link. If an output driver
fault is detected, the EEC switches from Active-Standby mode to Active-Active mode. This allows either channel
to control any of the output drivers independently, regardless of which channel is the preferred channel. This control
mode allows both channels to be engaged simultaneously and to manage different engine functions, providing an
effective fault accommodation strategy. If the crosstalk data link is lost, each channel maintains its current controls
prior the failure. If the engine subsystem control loop is no more possible (by any channel), the subsystem control is
set to its failsafe position.

-Active Oil Damper Valve (AODV) solenoid control - Variable Oil Reduction Valve (VORV) TM control
EEC SIGNALS :-
Fuel Flow Meter to Ch A, Oil Level sensor to CH B, Oil Debris Monitoring (ODM) sensor feedback signal (ch A)
via PHMU, Auxiliary Oil Pressure (AOP) sensor feedback signal via PHMU, - P ambient feedback signal (ch A),
- Ps14 feedback signal (ch B),- P25 feedback signal (ch A),- P3 feedback signal (2 pairs), T25 feedback signal (ch
A),- Core Nacelle Temperature feedback signal (ch B), - EGT feedback signal (2 pairs), - Auto Thrust (A/THR)
Disconnect P/B (ch B), - Flight Control Unit (FCU) A/THR engagement (ch B),

NAI:
- Upstream PRSOV solenoid control signal (ch B),
- Downstream PRSOV solenoid control signal (ch A),
- Upstream pressure sensor feedback signal (ch B),
- Downstream pressure sensor feedback signal,
- Dual temperature sensor feedback signal.
In Thrust Reverser SYS Tertiary Lock Valve (TLV) solenoids are controlled independently by SEC.

The Electronic Engine Control (EEC) is electrically supplied by the A/C electrical network when high pressure
rotor speed (N2) is below 10% or when the dedicated Permanent Magnet Alternator (PMA) has failed, and then by
its dedicated PMA when N2 is above 10%.Two transformer rectifiers provide 28V DC power supply to channels A
and B. Switching between the A/C 28V DC supply and the dedicated alternator power supplies is done
automatically by the EEC.
The Prognostics and Health Management Unit (PHMU) receives aircraft 28V DC directly from the aircraft normal
DC power bus through the EIU. The de-powering conditions are the same as the EEC. The Fan cowl door proximity
switches are supplied by another bus in 28V DC. Power is also transferred to the reverser system valves for
Directional Control and Isolation. Each starting igniter is independently supplied with 115V AC. 115 V AC from
aircraft electrical system is supplied to the ignition exciter via EIU which provides the necessary voltage to the
igniter plugs to generate the spark for combustion. 1 - 3 sparks per second normally. Alternate igniter every 2 start
attempts. The ignition system is composed of a dual channel ignition exciter supplying two spark igniter plugs.
During an automatic start, the EEC opens the SAV to motor the engine for start. The ignition exciter is then
energized when the HP rotor speed is nominal. The EEC provides full protection during the start sequence.
When the automatic start is completed, the EEC closes the SAV and cuts off the ignition. In case of an incident
during the automatic start the EEC makes a second attempt or aborts the start procedure.
There is no automatic shutdown function or second attempt in MANUAL START.
When the engine reaches the minimum fuel pressurization speed (18% N2), the EEC activates one igniter and
controls the appropriate fuel flow to the burner. When N2 reaches 51% N2, the automatic start sequence ends when
the EEC controls the SAV to close and the igniter to OFF. The EEC has the authority to abort a start only on the
ground. The EEC will abort the start, dry motor the engine for 30 seconds and attempt a single start for the
following reasons:
- no light up (EGT low and constant),
- no N2 acceleration (hung start),
- EGT reaches starting limit (impending hot start).
The maximum EGT during start sequence is 700º C
The EEC will abort a start, dry motor the engine for 30 seconds and not attempt a restart for the following
conditions:
- Failure of automatic restart,
- N1 locked rotor,
- EEC unable to command both igniters,
- Loss of EGT indication (T5 sensors failed),
- EEC unable to control fuel flow.
The EEC will also abort a start, will not dry motor the engine and will not attempt a restart if the starter duty cycle
is exceeded.
Manual start abort:
The automatic start sequence can be manually aborted by selection of the ENG MASTER lever to OFF position.
This leads to:
- SAV closure,
- Igniter(s) off,
- FMV, LP and HP fuel shut-off valves closure
NOTE: EEC does not dry motor the engine when an automatic start is manually aborted.

During continuous ignition both igniters are active. Following a ground start, the rotary selector must be moved
back toNORM before continuous ignition can be manually selected by moving it back to IGN/START position.
Continuous ignition shall remain commanded by the EEC until the rotary selector is moved back to NORM. In the
event that data position of the rotary selector sent by Engine Interface Unit (EIU) to EEC is not available or invalid,
the EEC shall use the last valid value of the rotary selector position if the aircraft is on ground until a valid
configuration is received again.Automatic command:
The EEC automatically commands continuous ignition at the following conditions:
- If an engine flameout is detected in flight, or during takeoff, igniters are kept on for a minimum of 30 seconds
after the engine has recovered from the flameout and reached idle,
- If a surge is detected in flight or during takeoff, igniters are powered until 30 seconds after the surge recovers,
- If the EEC detects a quick relight (Master Lever cycled from ON to OFF and back to ON in flight),
- If TCM Cutback is commanded.
Automatic continuous ignition shall be inhibited if the burner pressure (PB) is above 150 psi (the
nominaldeteriorated igniter quench point) to preserve igniter life.
The dry cranking procedure is used to motor the engine to remove unburned fuel from the combustion chamber or
cool down the engine or for some fuel or oil leak tests. The dry motoring can be interrupted at any time by pushing
the ENG MAN START pushbutton to OFF or positioning the ENG MODE rotary selector to NORM position.
The usual starter duty cycle is 3 starter crank cycles or 4 minutes maximum of continuous cranking. A 30 minutes
cool down period is necessary for additional use.
WARNING: the EEC is able to initiate a start sequence immediately following a dry motoring sequence by setting
the ENG MODE rotary selector to IGN/START position and the ENG MASTER control lever to ON position.

The wet cranking procedure is used to motor the engine for specific fuel or oil leak tests.The fuel flow is
commanded but both ignition systems are isolated. The fuel goes through the IFPC to the actuator fuel pressure
lines, the engine fuel manifolds (primary fuel lines only), and nozzles. Fuel is then sprayed in the combustion
chamber.
- the ENG MAN START P/B is set to ON. (SAV opening). When N2 speed stabilizes, the ENG MASTER lever is
set to the ON position to command the fuel flow. After 15 seconds, the ENG MASTER lever is set to the OFF
position to cut the fuel supply. The SAV command is maintained 30 seconds to blow all the fuel from the engine.
The wet motoring ends by pushing the ENG MAN START pushbutton to OFF or/and positioning the ENG MODE
rotary selector to NORM position.

The Electronic Engine Computer (EEC) will abort the automatic start,dry motor the engine for 30 seconds and
attempt a single auto-restart for the following reasons:
- No light up (Exhaust Gas Temperature (EGT) low and constant),
- No N2 acceleration (hung start),
- EGT reaches starting limit (impending hot start or surge).

NO LIGHT UP
If during an automatic start, the EEC identifies a low EGT:
- It shuts down the fuel supply and the selected igniter,
- It generates the ECAM alert "ENG x IGN A(B) FAULT",
- It maintains the Starter Air Valve (SAV) open to clear fuel vapors andcool the turbine for 30 seconds,
- Then it controls simultaneously the fuel flow and both igniters,
- When N2 reaches the starter cutout speed (or the light up is confirmed), it switches the igniters off and controls the
SAV closure 1 seconds after (or 1 seconds after the starter duty cycle is exceeded).
The engine continues to accelerate and stabilizes at idle speed. If this auto-restart attempt fails, the start is aborted
and the EEC will generate the ECAM alerts "ENG x START FAULT (IGNITION FAULT)" and "ENG x IGN A+B
FAULT".

IMPENDING HOT START

If during an automatic start, the EEC identifies an impending hot start, it maintains the SAV open, the selected
igniter on and controls a fuel depulse procedure: it cycles fuel off for 2 seconds and back on for 12 seconds via the
Fuel Metering Valve (FMV) for a maximum of 28 seconds to lower EGT below the limit. The EEC will generate
the ECAM alert "ENG x START FAULT (HOT START)". If the fault disappears, the starting sequence goes on
normally up to the engine stabilizes at idle speed. If the fault is still present, the EEC shuts down the fuel supply and
the igniter, performs a dry motor for 30 seconds and attempts a single auto-restart. If this auto-restart attempt fails,
the start is aborted and the EEC will generate the ECAM alert "ENG x START FAULT (EGT OVERLIMIT)"

AIR SYSTEM:-
The main air sources are the fan discharge air, Low Pressure Compressor (LPC) discharge air, High Pressure
Compressor (HPC) 3rd stage air and HPC 6th stage air.
The compressor control system optimizes the compressor performance
and its stability during engine start, transient and reverse thrust operations.
The two subsystems that comprise the compressor control system are
the:
- Compressor Stator Vane Control System,
- Compressor Bleed Control System.
STATOR VANE CONTROL SYSTEM:- The first stage LPC stator vanes and the HPC Inlet Guide Vanes
(IGV) and the 1st, 2nd and 3rd HPC stages have variable stator vanes. The Electronic Engine Control (EEC) controls
the vanes positioning to adjust the compressor airflow via three Stator Vane Actuators (SVAs) and mechanical
linkages. Each of the LPC SVA and the primary HPC SVA comprises an electrically controlled dual coil torque
motor and a fuel operated Electro-Hydraulic Servo Valve (EHSV). The secondary HPC SVA is a slave of the
primary. The three SVA Linear Variable Differential Transformers (LVDTs) transmit the piston position to each
EEC channel individually.
BLEED CONTROL SYSTEM :- The compressor bleed control system comprises one LPC Bleed Valve
Actuator (BVA) and two HPC bleed valves. The LPC bleed system is used to control the LPC discharge 3 rd stage
airflow into the fan discharge. The EEC modulates the LPC BVA and mechanical linkages accordingly. The LPC
BVA comprises an electrically controlled dual coil torque motor and a fuel operated EHSV. The actuator LVDT
transmits the piston position to each EEC channel individually. The HPC bleed system is used to control the HPC
6th stage airflow into the core area. The system has two ON-OFF HPC bleed valves; one is active, the other passive,
and both spring-loaded open and pneumatically closed at certain engine operating conditions. The active valve is
EEC controlled closed through the HPC bleed valve solenoid thanks to Ps3 pressure. The passive valve closes when
the pressure inside the HPC is high enough to force the spring loaded valve closed. Both are monitored by the EEC
thanks to two dedicated pressure sensors.
TURBINE ACTIVE CASE COOLING SYSTEM:- The Turbine Active Case Cooling (ACC) system cools
and controls the expansion of the turbine case to match the radial expansion of the rotary parts; this improves the
fuel efficiency and extends the turbine case life. The EEC modulates the turbine ACC air valve ( The valve is closed
during engine start and idle; partially open during take off and climb; fully open during cruise. ) to let some fan air
flow be discharged via manifolds and tubes around the LP and HP turbine cases. The turbine ACC air valve
comprises an electrically controlled Single Stage Servo Valve (SSSV) and a fuel operated actuator that operates the
butterfly. An LVDT transmits the piston position to the EEC channel A.
TURBINE COOLING AIR SYSTEM :- The Turbine Cooling Air (TCA) System is a passive system that
provides a continuous flow of cooling air inside the turbine cases. The system consists of 19 external tubes or
jumpers that direct calibrated HPC bleed air (3 rd and 6th stages) to the followings:
- High Pressure Turbine (HPT) 2nd stage vanes,( HPC 6th stage air cools, the others are cooled by HPC 3rd stage air.)
- Inter-stage HPT cavity,
- Turbine Intermediate Case (TIC) Stator Vanes, including the inner andouter diameter cavities,
- Low Pressure Turbine (LPT) case outer cavity and LPT rotor inter-stag avities.
ENGINE BEARING COOLING SYSTEM :- The engine bearing cooling system provides cooling buffer air
to the engine main bearing compartments and supplies sealing air to prevent oil leakage. It consists of:
- the buffer/ventilation system for bearing numbers 1, 1.5, 2, 3, 5 and 6,
- the engine bearing cooling system for bearing number 4.
BUFFER / VENTILATION SYSTEM:- The bearing compartments numbers 1, 1.5, 2, 3, 5 and 6 are cooled
and pressurized by the HPC 3rd stage through the LP buffer shutoff valve at low power or by the 2.5 bleed air valve
at high power through the LPC check valve. The LPC check valve is a passive device that is open until the HPC
3rd stage pressure delivered by the LP buffer shutoff valve is higher than the 2.5 pressure, to prevent a reverse flow.
The LP buffer shutoff valve is open through the integrated EEC controlled HPC buffer shutoff valve solenoid
thanks to Ps3 pressure. The cooling buffer air is distributed to the bearing compartments via external and internal
tubing, including LP shaft. For monitoring, the Buffer Air Pressure Sensor (BAPS) provides a buffer air pressure
signal to both EEC channels.
NUMBER 4 BEARING COOLING SYSTEM:- The Buffer Air Heat Exchanger (BAHE) uses station 2.5
bleed air to cool HPC 3rd stage air before it is delivered to the number 4 bearing housing. The station 2.5 air exits the
BAHE and is routed into the fan discharge.
COMPARTMENT COOLING:- The compartment cooling system ensures the ventilation of the fan
compartment, the core compartment and dedicated components inside the core compartment. The cooling of the fan
compartment is achieved through a passive ventilation system. Outside airflow circulates from the top scoop around
the fan case and exhausts through bottom holes and gabs of the fan cowls. The cooling of the core compartment is
achieved through a passive ventilation system. Fan bypass airstream is directed to the nacelle core, ignition leads,
igniter plugs and Environmental Control System (ECS) bleed valves through openings on the inner contour of the
thrust reverser cowl doors and exhausts through bottom holes and gabs of the Inner Fixed Structure (IFS) trailing
edge. Additional tubes are dedicated for the cooling of the ACC Valve, Starter Air Valve (SAV) and the Flow
Divider Valve (FDV).

The throttle control lever is linked to a mechanical rod. This rod drives the input lever of the throttle control
artificial feel unit. A mechanical rod transmits the throttle control lever movement. It connects the throttle artificial
feel unit to the input lever of the throttle control unit. The input lever drives two gear sectors assembled face to face.
Each sector drives itself a set of one resolver and three potentiometers. The relationship between the throttle lever
angle and throttle resolver angle (TRA) IS LINEAR AND 1 DEG.TLA = 1.9 TRA. The accuracy of the throttle
control unit (error between the input lever position and the resolver angle) is 0.5 deg.TRA. The maximum
discrepancy between the signals generated by two resolvers is 0.25 deg.TRA. The TLA resolver operates in two
quadrants. The first quadrant is used for positive angles and the second quadrant for negative angles. Each
resolver is dedicated to one FADEC channel (ECU / EEC) and receives its electrical excitation current (6 VAC)
from the related FADEC channel (ECU / EEC) The ECU considers a throttle resolver angle value: less than -47.5
deg.TRA or greater than 98.8 deg.TRA as resolver position signal failure. The ECU includes a resolver fault
accommodation logic. This logic allows engine operation after a failure or a complete loss of the throttle resolver
position signal.The throttle control unit comprises:
-An input lever
-Mechanical stops, which limit the angular range
-2 resolvers (one resolver per FADEC (ECU/EEC)
-6 potentiometers installed three by three
-A device, which drives the resolver and the potentiometer
-A pin device for rigging the resolver and potentiometers
-1 switch whose signal is dedicated to the EIU
-2 output electrical connectors
The throttle control lever moves over a range from -20 deg.TLA (Reverser Full Throttle stop) to +45 deg.TLA. In
the forward thrust area, there are two detent points, the MAX CLIMB detent point set to 25 deg.TLA and the MAX
CONTINUOUS/FLEX TAKE-OFF detent point set to 35 deg.TLA. In the reverse thrust throttle range, there is one
detent point at – 6 deg.TLA. This position agrees with the selection of the thrust reverser command and the Reverse
Idle setting. In the forward range (35 deg. To 45 deg.TLA), the autothrust function cannot be activated (except in
alpha floor condition).This range agrees with the selection of FLEX TAKE-OFF/MAX TAKE-OFF Mode.
The main thrust monitoring parameter is the N1 speed (LP shaft).
The main thrust demand parameter is the engine Fuel Flow (FF).
An additional Soft Go-Around (SGA) mode (Thrust limit mode) is available. It is automatically selected if during
approach, the TOGA detent is set and the thrust levers are then moved back to the FLX/MCT detent.
For each thrust limit mode selection, an N1 rating limit is computed by the EEC according to Thrust Lever Angle
(TLA) and the air data parameters from the Air Data Inertial and Reference Units (ADIRUs). This indication is
displayed in green on the upper ECAM display near the thrust limit mode indication.
The A/THR function is engaged manually when the A/THR P/B is selected or automatically at take-off power
application. In case of Alpha Floor detection, the A/THR function becomes active automatically and the N1 target is
to TOGA.
THRUST CONTROL MALFUNCTION:- The Thrust Control Malfunction (TCM) is a FADEC protection
function against un-commanded and uncontrollable excessive power excursion in which the normal thrust control
becomes inoperative.
NOTE: Note: The FADEC logic uses TCM permission data from FMGCs to FCU to automatically reduce engine
thrust during flare.

Both the N1 and N2 speed sensors are dual channel magnetic speed sensors and transmit the corresponding signals
to the EEC for processing and monitoring and to the PHMU via the EEC for vibrations computation. The EEC uses
the Fan Speed sensor to detect de-coupling of the Fan Shaft from the LP shaft (sheared shaft) by comparing the Nf
to the N1. The PHMU uses the Fan Speed from the EEC in conjunction with Fan Rotor vibrations to monitor Fan
Rotor vibration and calculate trim balance solution for maintenance purposes.

The engine EGT is sensed and averaged by four thermocouple probes (T5 probes) located around the circumference
of the Turbine Exhaust Case (TEC). Each probe is a single channel Chromel / Alumel thermocouple. The signals
from the two T5 probes on the left side of the engine are electrically averaged and sent to Channel A of the EEC.
The signal from the two T5 probes on the right side of the engine are electrically averaged and sent to channel B of
the EEC.

The Fuel Flow Meter (FFM) is a magnetic drum and impeller type. The fuel used value is computed by the EIS
from the fuel flow value sent by the EEC.

The Main Oil Pressure (MOP) sensor is located on the left hand side of the engine on the Oil Control Module
(OCM), rear lower side. It is a dual channel sensor which sends the signal to the EEC for monitoring. The Main Oil
Temperature (MOT) sensor is a dual channel sensor and is used to measure the temperature of the scavenge oil
returning to the tank. The sensor is located on the front face of the OCM. An Auxiliary Oil Pressure (AOP) sensor is
located on the left side of the engine, below the Variable Oil Reduction Valve /Journal Oil Shuttle Valve
(VORV/JOSV). It measures the pressure of oil delivered to the journal bearings in the Fan Drive Gear System
(FDGS). It sends a signal to the EEC, where it is used in conjunction with other oil parameters to detect a Fan Drive
Gearbox (FDG) auxiliary oil supply malfunction. The Oil Debris Monitoring (ODM) sensor is located on the top
front side of the oil tank. It sends signals proportional to size and type of the pollution particles to the PHMU. The
PHMU monitors the debris for quantity and identifies whether it is ferrous or non-ferrous debris. The data is
transmitted to the EEC for analysis and to generate an ECAM message and trend monitoring accordingly. The data
is also stored in the Data Storage Unit (DSU).

VIBRATION PARAMETERS DESCRIPTION:- The vibration monitoring function within the PHMU uses
the two vibration sensors to measure the Fan related vibrations (VIB N1) and the Core related vibrations (VIB N2),
stores this information and sends it to the EEC. It is used for ECAM display in the ENGINE SD page. It's also used
for the fan trim balance procedure. The PHMU receives Nf, N1 and N2 data from EEC to capture and compute the
appropriate vibration data. The Forward Vibration Sensor is a single channel piezoelectric accelerometer, installed
at 10 o'clock on the HP Compressor casing. The Aft Vibration Sensor is a single channel piezoelectric
accelerometer, installed at 3 o'clock on the LP Turbine casing. If the signal from one vibration sensor (either
forward or aft vibration sensor) is lost during engine operation, the vibration monitoring function is still able to
provide both vibration signals (N1 and N2) for cockpit display. However, the display for the affected sensor will be
presented in degraded mode.

The nacelle temperature is monitored by a temperature probe installed in the ventilated core compartment. The
nacelle temperature is displayed on the ECAM ENGINE SD, except during starting or cranking sequences where it
is replaced by starting parameters. The T2 sensor measures the air inlet temperature for engine rating, Mach
number calculation and bleed scheduling.

THRUST REVERSER SYSTEM :- The thrust reverser system is of the aerodynamic blockage type. For each
engine, it consists of two translating sleeves, ten blocker doors and cascade vanes to redirect fan discharge airflow.
Each system is made of one Hydraulic Control Unit (HCU) including an Isolation Control Valve (ICV) and a
Directional Control Valve (DCV), two worm drive actuators per side, locking and monitoring devices. Safety
(primary locks in each actuator and one tertiary lock at the bottom of each translating sleeve.)
Deploy sequence :- When the thrust-reverser lever is set to the deploy position, the following sequence occurs.
1-As soon as the Spoiler Elevator Computers (SECs) receive the signal from the TCU potentiometers (Throttle
Lever Angle (TLA) < -3°), and from the Radio Altimeter (RA) (altitude < 6 ft), they control the powering of the
TLVs to open. In this position, the TLVs are ready to let the hydraulic pressure release the Track Lock (TL) when
the ICV will be controlled open.
2-When the Engine Interface Unit (EIU) receives the signals from the Throttle Control Unit (TCU) switch (TLA <
-3.8°) and from the Landing Gear Control and Interface Units (LGCIUs) (aircraft on ground), it controls the closure
of internal relays involved in the ICV and DCV powering.
3-When the Electronic Engine Control (EEC) receives the signals from the TCU resolvers (TLA < -4.3°), it closes
an internal relay to power the ICV to open. The pressure is sent to the actuators rod chambers to perform an
overstow and to the TLs to release the latches.
4- When the EEC receives the signals from the TCU resolvers (TLA < -4.8°) provided the TLs are confirmed
unlocked, it closes an internal relay to power the DCV to open. The pressure is sent to the actuators jack heads to
release the actuators internal primary locks and command the translating sleeves deployment.
5-Above 85 % of travel, the EEC commands the engine to accelerate from reverse idle to max reverse thrust.
Maximum allowable thrust is defined as a function of sleeve travel and TLA. At 95% of travel, the actuators engage
their integral snubbing devices, thus decreasing their extension speed before the full opening. The TLV, ICV and
DCV remain supplied to maintain the translating sleeves fully deployed by hydraulic pressure.
Stow sequence:- When the thrust-reverser lever is set to the stow position, the following sequence occurs.
1-When the EEC receives the signals from the TCU resolvers (TLA > -4.8°), it de-energizes the DCV. The pressure
is sent only to the actuators rod chambers to stow the translating sleeves until the actuators internal primary locks
are re-engaged.
2-15 seconds after the SECs receive the signals from the TCU potentiometers (TLA > -2°), they de-energize the
TLVs to re-engage the TLs.
3-15 seconds after the stow sequence is completed, the EEC de-energizes the ICV. Then the EIU opens its internal
relays to isolate the ICV and DCV powering.
GROUND ASSISTED STOW SEQUENCE (GASS) :- The EEC shall initiate a thrust reverser GASS
operation on ground only in order to lock the thrust reverser system in the following two cases:
- at least one primary lock is detected unlock after the normal stow sequence is completed (operational case),
- if at least one primary lock is detected unlock after the engine start (maintenance case).
The GASS shall be initiated by energizing the ICV for 5 seconds when all the following conditions are fulfilled:
- the aircraft is on ground,
- the throttle is in forward thrust region and less than CL position,
- no stow sequence is being commanded,
- within 15s after engine transition to idle following an engine start,
- one or two primary locks of any translating sleeve are seen unlocked,
- the sleeve positions (left and right) are less than 5% of travel,
- the thrust reverser is not inhibited,
- 28V DC power is available.

OIL SYSTEM:- The oil system:

- Lubricates the engine bearings, Angle Gearbox (AGB), Main Gearbox (MGB) and Fan Drive Gear System
(FDGS) with filtered, non-pressure regulated oil,
- Regulates the temperature of the engine oil with the Air/Oil Heat Exchanger (AOHE), engine fuel with the
Fuel/Oil Heat Exchanger (FOHE), Integrated Drive Generator (IDG) oil with IDG Oil/Oil Heat Exchanger
(IDGOOHE),
- Scavenges the hot lubrication oil back to the tank,
- Vents overboard the excess of sealing air from the bearing compartments.
Oil flows from the pressurized oil tank to the lube pump in the Lubrication and Scavenge Oil Pump (LSOP).The
pressurized oil is directed to the main oil filter and to the Oil Control Module (OCM). The main part of the filtered
oil flows to the Fuel/Oil Heat Exchanger Bypass Valve (FOHEBV) ( Controlled and monitored by EEC to modulate
the oil flow between AOHE and FOHE LVDT provides feedback to EEC. At low fuel temperature, oil flow increases
to FOHE, about 92.5%.) which modulates the oil flow between the AOHE and the FOHE. The oil flow that is
directed to the AOHE also flows through the IDGOOHE. The FOHEBV is electrically controlled and monitored by
the Electronic Engine Control (EEC) according to fuel temperature. Oil from the heat exchangers is sent via the
OCM to the No. 3, 4, 5, 6 bearings and to the AGB and MGB. Oil is also sent to the Variable Oil Reduction Valve
(VORV) / Journal Oil Shuttle Valve (JOSV) which modulates the flow of oil to the No. 1, 1.5, 2 and Fan Drive
Gear System (FDGS) based on engine power settings.
The VORV is electrically controlled and monitored by the EEC to bypass part of the oil flow to the front bearings
at low power setting.( VORV is controlled by EEC and feedback by LVDT. It gives max. flow when a/c take off, fail-
safe position is at max. flow. VORV is electro-hydraulic servo valve. )
The JOSV is a mechanical device that keeps a continuous supply of oil to the fan drive journal bearings from the
main oil supply in normal condition or from the auxiliary oil supply in windmill or zero or negative gravity
conditions.
Nozzles in the main bearing compartments and gearboxes supply the oil to the different bearings, gears, seals, and
accessory drive splines. Last chance strainers are provided at the entrance to the compartments to protect the oil
nozzles from debris introduced to the oil system downstream of the main oil filter.
The other part of the filtered oil is sent through the Active Oil Damper Valve (AODV) to the No. 3 bearing damper
for N2 vibration control. The AODV is electrically controlled by the EEC to supply oil to the damper during
starting and acceleration and shut it off at high power.( The valve is a dual-coil solenoid scheduled on or off by EEC.
The valve will provide an open or closed position. It limits N2 spool vibration; Optimizes No.3 bearing loads during
all phases of operation; Provides bowed rotor protection at sub-idle.)
OIL SCAVENGE AND VENTING :- The engine oil scavenge system is used to return the hot lubrication oil
to the tank through the LSOP. The LSOP has six scavenge pumps that are used to pull scavenge oil from the:
- No. 1, 1.5, 2 bearing and FDGS,
- No. 3 bearing compartment,
- No. 4 bearing compartment,
- No. 5 and 6 bearing compartment,
- MGB,
- AGB.
Six magnetic chip collectors, installed upstream of the scavenge pumps, catch ferrous metal particles.The scavenge
pumps send the scavenge oil to the oil tank through the Oil Debris Monitor (ODM) and the deaerator. The ODM
senses the size and quantity of ferrous and non-ferrous particles in the scavenge oil system and the corresponding
signal is processed by the Prognostic Health Monitoring Unit (PHMU). The engine oil breather system is used to
remove sealing air from the bearing compartments, separate the air from the oil, and vent it overboard. In the tank,
the deaerator is a static component that separates the air that is mixed with the scavenged oil. Part of the air is used
to pressurize the tank and the excess is sent to the centrifugal deoiler. The deoiler is mechanically connected and
driven by the MGB and receives the air/oil mist internally from the MGB, from the tank by the breather line and
from the No. 3 bearing compartment by a dedicated breather vent tube.

The oil level sensor is installed on the top of the oil tank. It is of the magnetic float and reed switch type. The signal
proportional to the oil level is sent to the EEC channel B.
The Oil Debris Monitoring (ODM) sensor is installed between the main oil scavenge line and the deaerator in the oil
tank. It detects any type of pollution that crossed its electromagnetic field. The signal corresponding to the ferrous
and non-ferrous debris is processed by the PHMU. The PHMU calculates the number of particles in a given time
period and sends it to the EEC channel A. The EEC compares the data to predefined values and generates a
maintenance signal.
The low oil pressure switch is installed on OCM (Main oil pressure & temperature & oil differential pressure sensor
also). It detects low oil pressure condition on the oil supply line and sends the signals to the Engine Interface Unit
(EIU).
The dual auxiliary oil pressure sensor is installed on the VORV / JOSV assembly. It measures the pressure of the
auxiliary oil supply for the journal bearings of the FDGS and sends it to both EEC channels to detect failures in the
JOSV or the oil auxiliary pump.

DO NOT ATTEMPT TO OPEN THE FAN COWL DOORS IF THE WIND SPEED IS HIGHER THAN 96 KM/H
(60 MPH).To open Pull down in sequence each handle (first the AFT then the CENTER then the FWD) to open the
three latches.

DO NOT KEEP OPEN A THRUST REVERSER DOOR WHEN THE WIND SPEED IS 83.5 KM/H (51.6 MPH)
OR MORE. NOTE: The closure assist assembly only helps to open or close the L1A and L1B latches. It is not
necessary to use the closure assist assembly if you can open and close these latches without it. On the Thrust
Reverser Cowl, push the latch trigger to release and open the latches in sequence: L5, L4, L3, Bifurcation Latching
System (BLS), L2, L1A and L1B.

If possible, the engine oil should be checked and serviced within 05 to 60 minutes after engine shutdown.If the
engine has been shutdown for more than 2 hours,dry-motor the engine until the oil pressure is stable.

OIL TANK CAPACITY :- 39.6 QUARTS (37.4 LTRS)

OIL TANK FULL LEVEL :- 34.9 QUARTS (33.1 LTRS)

CHIP COLLECTORS:- The engine oil scavenge system has six magnetic chip collectors which catch ferrous
metal particles that might exist in the scavenge and supply oil:
The No. 4 bearing magnetic chip collector is located in the No. 4 bearing oil scavenge line.
The Angle Gearbox (AGB), Main Gearbox (MGB), No. 1, 1.5 and 2Bearing and Fan Drive Gear System
(FDGS), No. 3 bearing, and No.5 and 6 bearing magnetic chip collectors are located on the lubricationand
scavenge oil pump, at the 6 o'clock position.The six chip collectors are bayonet-type plugs, they are LRUs.

For IDG servicing the left thrust reverser cowl-door has to be opened as the IDG installation change to core
mounted area. The IDG has two new additional sensors (oil level sensor and oil filter DPI) providing warnings IDG
OIL LVL, IDG FILTER CLOG, which permit to increase the periodic inspection interval.

ATA 26

The PW has 3 fire detectors (pylon, AGB and core).

The avionics SMOKE detector, which is installed in the extraction duct, is used for the detection of smoke from the
computers and control boxes. The detector is monitored by the AEVC. The smoke detector directly sends the signal
to FWC for the AVIONICS SMOKE warning in the cockpit.

ATA 30

Hot air for the Nacelle anti-ice system is supplied by a dedicated HP Compressor (HPC) bleed on the PW1000G, 6 th
stage. The NAI System is controlled and monitored by the (Propulsion Control System (PCS) (Engine Electronic
Controller (EEC) and Engine Interface Unit (EIU)). Each engine NAI System consists of two electrically
controlled, pneumatically operated Pressure Regulating and Shut-Off Valves (PRSOV). The EEC energizes the
solenoid to CLOSE the PRSOV. Therefore, in case of loss of electrical power supply, the valves will go fully open
provided the engine bleed air supply pressure is high enough. In the absence of air pressure, the valve is spring-
loaded to the closed position.
Each engine NAI system consists of one command P/B SW but two Pressure Regulating and Shut -Off Valves
(PRSOVs) for good operability,two Pressure Transducers (PTs), temperature protection and supply ducts.
PRSOV 1 is controlled by EEC Channel A and PRSOV 2 is controlled by Channel B. Each PRSOV pneumatically
regulates the downstream air pressure.
The EEC does a detailed monitoring of the PRSOVs with two PTs (PT1 & PT2) located downstream each PRSOV.
PT1 is located in between the PRSOVs in the core engine area. It gives the feedback to channel B only and use for
trouble shooting. PT2 is located downstream of PRSOV 2 in the fan case. It gives the feedback to both the EEC
channels for monitoring function in case of single failure of EEC channel. A dual temperature sensor located in the
fan case, provides the EEC (one per channel) with the fan compartment temperature measurement for NAI leakage
detection.
The PB "FAULT" light is triggered by the EIU based on the input from EEC. It appears when the engine is running
and NAI is failed in OPEN or CLOSED. It also appears in case of monitoring fault. The fail safe position of the
valves in case of EEC dual channel failure is OPEN. In case of a single valve failure, the corresponding valve being
failed open, the anti-ice function is still available. Master Minimum Equipment List (MMEL) IMPACT- In case of
both NAI valve failures, dispatching with one of the two valves locked close will not be possible.

ATA 28

The benefit to combine both layouts (A320 & A321 FUEL SYSTEM), on the new A319/A320 Fuel System, is to
achieve the following:
- Weight reduction, - Better protection against UERF,
- Cost improvements, - Communality in between all SA Aircraft variants.
Fuel transfer from the center tank to the wing tanks is controlled by transfer valves. When the transfer valves are
opened, they supply pressure to two jet pumps in the center tank and transfer the fuel from the center tank to the
wings.
The Refuel/Defuel panel functions are:
- Automatic or manual refueling, - High level test, - Defueling, - Fuel transfer, - Refueling on batteries.
The 2-channel Fuel Quantity Indication Computer (FQIC) calculates the fuel mass, controls automatic refueling and
monitors the system with different interfaces.
CDCCL:- These regulations are related to the prevention of ignition sources in fuel tanks of current type certificated
aircraft. The function of the CDCCL is to give instructions to prevent critical ignition source feature from
alterations, repairs or maintenance actions during configuration change. For AIRBUS this document is called the
Fuel Airworthiness Limitations and it is added to the Airworthiness Limitation Section part 5.
PUMP LOGIC:- While fuel is supplied from the center tank, the wing tanks will stay full and will possibly overfill
because the returned fuel is supplied to the wing tanks. If this occurs, the center tank transfer valves close when the
inner cell gets to the FULL level sensor. The wing tank pumps will supply the fuel to the engine until approximately
500 kg (1100 lbs) of fuel are used and the UNDERFULL sensor is reached. The logic circuit then open the center
tank transfer valves again.
FRTT STOPS WHEN:-
1)The FRTT closes if the center tank transfer valves do not obey thelogic signals of the full level sensors. This
causes the wing tank to overflow through the tank ventilation system into the vent surge tank.
The overflow sensor sends an electrical signal to the FLSCU. The FLSCU sends a closure signal to the EEC
through the Engine Interface Unit (EIU). The EEC closes the FRTT and stops the fuel supply back to the outer cell.
2) The FRTT closes if the fuel temperature is too high in the outer cell, i.e. 52.5°C
3) The FRTT closes if the fuel temperature in the inner cell is too high,i.e. 55°C
4) The FRTT closes if a fuel pump Low Pressure (LP) is sensed by all pump pressure switches of one wing for the
related engine when the crossfeed valve is closed, or if a fuel pump LP is sensed by all pump pressure switches of
the two wings when the crossfeed valve is open. This is to stop the return fuel flow during engine gravity feeding.
LP is sensed by the pump LP switch and a signal is sent to the FLSCU.
5) The FRTT closes when the fuel level in the inner cell decreases to the INNER LOW LEVEL sensor at 280 kg

ATA 36

The pneumatic system operates electro-pneumatically. There is one BMC for each engine bleed system. Both BMCs
exchange data. In this NEO configuration, one BMC can control & monitor both sides when the other BMC fails.
Air is bled from an Intermediate Pressure (IP) stage (HP3) or the HP8 stage with the High Pressure Valve (HPV)
which is used for the pneumatic regulation. The Engine Bleed Air System (EBAS) uses electro-pneumatic valves.
The Pressure Regulating Valve (PRV) regulates the bleed air pressure. The PRV is used as a protective shut off
valve when the parameters are abnormal. In case of EBAS electrical failure, the PRV operates in back-up pneumatic
mode (Fail safe close function). On this PW Engine the OPV is installed in the engine core. The Fan Air Valve
(FAV) modulates Fan discharge air through an air-to-air heat exchanger called "Precooler" to reduce the Bleed
Temperature.
BMCs are Dual Channel computers. Each BMC channel A is a full digital channel embedding all the control and
monitoring functions. Channel B is a hardware part and back-up channel able to detect system overtemperature. For
the monitoring, the BMCs read pressure transducers (upstream / downstream of the PRV), Precooler Differential
Pressure and downstream temperature with the Bleed Temperature Sensor (BTS).

HP7 air to hydraulic reservoir.

LEAK DETECTION
Leak detection loops are installed along the hot air supply ducts of the pneumatic system. The loops are made of
multiple sensing elements connected in series to the BMCs Overheat Detection System (OHDS).If a leak is
detected, a signal is sent to the BMC 1 or 2 which automatically isolates the affected area by closing the crossbleed
valve and shutting off the engine bleed on the affected side. The leak detection system is organized into three loops.
Here are the loops and the protected areas:
- Pylon: dual loop from the precooler to the wing leading edge.
- Wing: dual loop from wing leading edge, including the wing air inlet supply, and belly fairing (cross bleed duct,
pack supply ducts and APU forward supply duct).
- APU: single loop at APU aft supply duct (left hand side of the fuselage) from APU firewall to wheel well area.
As compared to A320 CEO,the NEO engine has higher bleed air temperatures during High Pressure (HP) operation,
lower air pressure during Intermediate Pressure (IP) operation, lower fan pressures for cooling air flow supply and
limited space for installation due to new pylon configuration.To achieve better performance requirements a new
electro-pneumatic bleed air system is designed for A320 NEO.
Normally BMC 1 Channel A does all the control and monitoring of the LH EBAS and BMC 2 Channel A the RH
EBAS. Each BMC channel A controls torque-motor and solenoid for the electro-pneumatic valves, monitors
sensors. As both BMC interface, each one is capable to control both sides. The channel B is a fully hardware part
able to detect the system overtemperature: Electrical Protection Function (EPS). This detection is fully independent
from software part. Each BMC reports the failures independently of each other.
HPV (solenoid operated butterfly valve) regulates the pressure of the bleed air between 15and 65 psig.
PRVregulates the pressure of the bleed air at 42 ± 2 psig in normal dual bleed operation (50 ± 2 psig in single bleed
operation). Its setting is modulated by the electric command on the torque-motor.
The OPV, normally in spring-loaded open position will be fully closed if bleed pressure reaches 90 psig.
BLEED MONITORING PRESSURE SENSOR (BMPS) The Bleed Monitoring Pressure Sensor (BMPS) is
used to perform bleed port switching function. It is also used to estimate the position of the HPV butterfly and to
monitor the HPV and the PRV.
BLEED PRESSURE SENSOR (BPS) The Bleed Pressure Sensor (BPS) is installed downstream the PRV.
It provides to BMC the actual bleed air pressure delivered through the PRV. This sensor is also used by the BMC
for system monitoring (overpressure and low pressure alarms) and to monitor the position of the OPV butterfly.
DIFFERENTIAL PRESSURE SENSOR (DPS) The Differential Pressure Sensor (DPS) ensures the reverse
flow protection by sensing the differential pressure between Precooler hot side inlet and outlet. It also provides to
the BMC an indication of the PRV and OPV position. The dual Bleed Temperature Sensor (BTS) installed
downstream the Precooler provides to the BMC the actual EBAS temperature. The BMC uses EBAS temperature to
position the Fan Air Valve (FAV). The wiring connected to channel A of the BTS is fully segregated from the
wiring connected to channel B. Both BMCs interchange temperature measurements and can carry out both sides
temperature regulation. This dual sensor is also used by the BMCs for system monitoring (overtemperature and low
temperature alarms).
NOTE: Channel B of one BMC is connected to Channel A of the other BMC, so that in case of loss of temperature
monitoring and control in Channel A of one side, the opposite controller can take over control of the whole EBAS.
The FAV butterfly valve actuator rod is adjusted by the BMC via a torque motor servo-control depending on BTS
input. The BMC set point is 200°C (392°F) in normal operations and 160°C (320°F) in Climb and Hold with 2
bleeds and Wing Anti-Ice (WAI) off. With no electrical power and enough muscle pressure, the FAV valve is fully
open.
The Precooler is a stainless steel and nickel alloy air-to-air heat exchanger.
The PRV operates as a shut-off valve. It is commanded to close in the following conditions:
- Over-temperature downstream of the Precooler (BTS):
257°C (495°F) < T 270°C (518°F) during 55s,
270°C (518°F) < T 290°C (554°F) for 15s,
T > 290°C (554°F) for 5s.
- Overpressure downstream of the PRV > 60 ± 3 psig at BPS,
- Engine fire (consequence of crew action on the ENG FIRE P/B),
- Leak detection in pylon/wing/fuselage ducts surrounding areas,
- APU bleed valve not closed & APU BLEED P/B selected: Depending on the Crossfeed Bleed Valve (CBV)
position, only one PRV (left engine PRV if CBV is closed) or both (if XBleed is open).
- Reverse flow detected by DPS,
- ENG BLEED P/B selected OFF or ENG not running,
- Associated Starter Air Valve (SAV) not closed,
- HPV failed open,
- Dual BTS channels failed.

The pneumatic system uses 2 identical controllers with a microprocessor and command channel A and a back-up
channel B. Each channel is supplied by a different 28V DC bus bar. Both Bleed Monitoring Computers (BMCs)
will work as MASTER/SLAVE so long as the ARINC429 cross communication is working properly. If one
ARINC429 bus is lost from one BMC to the other, the BMC receiving no data will take over control and would
inform to the opposite BMC.

Each loop consists of sensing elements connected in series.

Page60