A380 TECHNICAL TRAINING MANUAL RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear This document must be used for training purposes only
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A380 TECHNICAL TRAINING MANUAL
ATA 32 LANDING GEAR
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Landing Gear Introduction (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Landing Gears and Doors Presentation (1) . . . . . . . . . . . . . . . . . . . . . 4
Landing Gears Extension and Retraction System Presentation (1) . . 20
Brake System Presentation (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Steering System Presentation (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Landing Gear Maintenance (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
TABLE OF CONTENTS
Jan 13, 2009
Page 1
A380 TECHNICAL TRAINING MANUAL
LANDING GEAR INTRODUCTION (1)
General
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The landing gear system supports the aircraft on the ground and transmits
landing, takeoff and taxi loads to the structure.
It also decreases the aircraft speed through the braking system and steers
the aircraft on ground.
The landing gear system includes:
- landing gears and doors,
- the Landing Gear Extension and Retraction System (LGERS),
- the Braking Control System (BCS),
- the Wheel Steering Control System (WSCS),
- the Tire Pressure Indicating System (TPIS),
- the Oleo Pressure Monitoring System (OPMS),
- the Brake Temperature Monitoring System (BTMS).
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEAR INTRODUCTION (1)
Jan 13, 2009
Page 2
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A380 TECHNICAL TRAINING MANUAL
GENERAL
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEAR INTRODUCTION (1)
Jan 13, 2009
Page 3
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
General
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There are five Landing Gears (L/Gs):
- two Wing Landing Gears (WLGs),
- two Body Landing Gears (BLGs),
- one Nose Landing Gear (NLG).
During flight, the L/G is retracted into bays.
Doors are operated mechanically and hydraulically to close when the
L/G retracts. The hydraulically operated doors also close after the L/G
is extended.
The oleo-pneumatic shock absorbers are monitored to give oleo pressure
to flight and maintenance crew through the Oleo Pressure Monitoring
System (OPMS).
NLG tires dimensions are different from BLG and WLG ones:
- NLG tire type is the same as the one mounted on the A321,
- WLG and BLG tire type is the same as the one mounted on the
A340-500/600.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 4
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A380 TECHNICAL TRAINING MANUAL
GENERAL
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 5
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Nose Landing Gear (NLG) & Doors
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The NLG is installed in the forward fuselage. It supports the forward part
of the A/C on the ground and transmits taxi, take-off and landing loads
to the airframe.
The NLG retracts forward into its bay and has these parts:
- a leg assembly that includes a shock absorber and a twin-wheel axle,
- a nose wheel steering mechanism that includes two actuators,
- a retraction actuator.
There are four doors for the NLG, those are:
- two forward doors,
- two rear doors.
- the forward doors are hydraulically operated and the rear doors are gear
operated.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 6
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A380 TECHNICAL TRAINING MANUAL
NOSE LANDING GEAR (NLG) & DOORS
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Nose Landing Gear (NLG) & Doors (continued)
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Nose Landing Gear Operation
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 8
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A380 TECHNICAL TRAINING MANUAL
NOSE LANDING GEAR (NLG) & DOORS - NOSE LANDING GEAR OPERATION
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 9
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Wing Landing Gears (WLGs) & Doors
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A WLG is installed in each wing. They support the A/C on the ground
and transmit taxi, take-off, landing and braking loads to the wing. Each
WLG retracts inboard into its wheel bay in the fuselage.
Each WLG has these parts:
- a leg assembly that includes a shock absorber and a four wheel bogie
beam assembly,
- a retraction actuator.
There are four doors for each WLG, a main door, an auxiliary door, a
fixed fairing door and a hinged door.
The main door operates hydraulically.
The auxiliary door is articulated and is operated by the main door.
The fixed fairing door and the hinged door are gear operated.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 10
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A380 TECHNICAL TRAINING MANUAL
WING LANDING GEARS (WLGS) & DOORS
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Body Landing Gears (BLGs) & Doors
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The two BLGs are installed in the center fuselage (between the two
WLG).
The BLG gives to the A/C a large footprint to spread the weight of the
A/C and transmits taxi, take-off, landing and braking loads to the fuselage.
BLG has steering capability on its aft axles.
The BLG retracts aft into a bay in the fuselage and has these parts:
- a BLG leg assembly that includes a shock absorber and a six wheels
bogie beam assembly,
- a retraction actuator.
There are four doors for each BLG:
- an inner door,
- an outer door,
- a center door,
- an auxiliary door.
The inner, center and outer doors are hydraulically operated.
The center door is folded inwards when the BLG extends.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 12
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A380 TECHNICAL TRAINING MANUAL
BODY LANDING GEARS (BLGS) & DOORS
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 13
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Body Landing Gears (BLGs) & Doors (continued)
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Wing Landing Gear & Body Landing Gear Operation
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 14
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A380 TECHNICAL TRAINING MANUAL
BODY LANDING GEARS (BLGS) & DOORS - WING LANDING GEAR & BODY LANDING GEAR OPERATION
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Oleo Pressure Monitoring System (OPMS)
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This system measures and gives the oleo pressure of the gears to the flight
and maintenance crew.
It monitors the pressure and temperature of the gears and transmits the
information to the Integrated Modular Avionics (IMA) through the
Landing Gear Remote Data Concentrator (L/G RDC).
The Oleo Pressure and Temperature Sensors (OPTS) acquire pressure
and temperature for each L/G.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 16
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A380 TECHNICAL TRAINING MANUAL
OLEO PRESSURE MONITORING SYSTEM (OPMS)
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 17
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS AND DOORS PRESENTATION (1)
Tire Pressure Indicating System (TPIS)
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Tire pressure is indicated to the flight and maintenance crew through a
Tire Pressure Indicating System (TPIS) hosted in the CPIOMs.
Tire pressure is measured by pressure sensor, one for each wheel and
sent to the CPIOMs through L/G RDC.
Note: The TPIS is installed as an option.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 18
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A380 TECHNICAL TRAINING MANUAL
TIRE PRESSURE INDICATING SYSTEM (TPIS)
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS AND DOORS PRESENTATION (1)
Jan 13, 2009
Page 19
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS EXTENSION AND RETRACTION SYSTEM PRESENTATION (1)
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General
The Landing Gear Extension and Retraction System (LGERS) controls
and monitors the extension and retraction of the Landing Gear (L/G).
The system is divided into three sub-systems:
- The normal extension and retraction system,
- The free fall extension system,
- The Ground Door Opening (GDO) system.
The normal extension and retraction system extends and retracts the L/G
in normal operation. The system is electrically controlled and
hydraulically operated.
The green hydraulic system supplies the hydraulic power to the Nose
Landing Gear (NLG) and the Wing Landing Gear (WLG) gears and doors
operation.
The yellow hydraulic system supplies the hydraulic power to the Body
Landing Gear (BLG) and doors operation.
A L/G control lever (1312VU) is used to start the extension or retraction.
If the normal extension and retraction system is not available, the gravity
assisted L/G extension can be made by using the free fall system.
The free fall system is electrically controlled and operated. A switch
(1311VU) is used to make the necessary extension selection.
The GDO system is operated on the ground from outside the A/C for
access to the L/G bays for maintenance.
Five ground door-opening handles adjacent to the L/G bays operate the
doors.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
Page 20
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A380 TECHNICAL TRAINING MANUAL
GENERAL
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
LANDING GEARS EXTENSION AND RETRACTION SYSTEM PRESENTATION (1)
Normal Extension & Retraction
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A L/G control lever in the cockpit is used to extend or retract the L/G.
The lever starts the electrical control.
The LGERS application, hosted in the CPIOMs, controls the L/G
extension/retraction operational sequence by sending control signals to
gear and door selector valves and to gear and door electrical uplock
actuators.
Doors and gears proximity sensors supply the Landing Gear Extension
Retraction System (LGERS) with the necessary position data through
the L/G Remote Data Concentrators (L/G RDCs). Later this position data
is sent to the ECAM page.
Independent proximity sensors send only L/G position to the independent
indication lights (1312VU) via L/G RDCs.
The LGERS also interfaces with other A/C systems to give gear status
and position information.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
Page 22
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A380 TECHNICAL TRAINING MANUAL
NORMAL EXTENSION & RETRACTION
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
Page 23
A380 TECHNICAL TRAINING MANUAL
LANDING GEARS EXTENSION AND RETRACTION SYSTEM PRESENTATION (1)
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Free Fall Extension
In the event that the normal system is not available to deploy the L/G,
the free fall system is an alternative and independent system that releases
the gears and doors from their uplocks.
The free fall system is independent from the Integrated Modular Avionics
(IMA) environment.
This independent system makes sure that a failure in the normal system
cannot prevent the free fall system from operating.
The system is activated from a dedicated free fall switch, installed on the
instrument panel in the cockpit.
The emergency extension operating sequence is controlled by a Free Fall
Control Module (FFCM), which is a dual system.
To get a free fall extension, the FFCM has to:
- Isolate the hydraulic supply pressure from the L/G hydraulic circuits;
this is achieved by cut out valves.
There is a cut out valve for each gear group (NLG, WLG and BLG):
- To get free flow between the ports of gear and door actuators; this is
achieved by vent valves.
There is a vent valve for each individual gear bay (NLG, L WLG, R
WLG, L BLG and R BLG):
- To release gear and door uplocks, such as the gears and doors can fall
under gravity.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
Page 24
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A380 TECHNICAL TRAINING MANUAL
FREE FALL EXTENSION
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
LANDING GEARS EXTENSION AND RETRACTION SYSTEM PRESENTATION (1)
Ground Door Opening (GDO) System
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Each L/G bay doors are independently operated by the GDO system.
Door opening and closing operations are done by means of a door opening
lever, installed on the GDO panel, adjacent to each L/G bay.
When the A/C is on the ground, the normal LGERS maintains the operated
doors in their closed and locked position.
To get door opening, first, the related hydraulic door actuator is isolated
from the LGERS hydraulic circuit.
This is achieved by using a door bypass valve that connects extend and
retract ports of the door actuator together and blocks the door close
pressure line.
There is one door bypass valve per individual door(s) operation (NLG,
L WLG, R WLG, L BLG and R BLG).
Following the door actuator isolation, the door uplock is unlocked and
the door opens under gravity.
Closing the door is accomplished in reverse order by resetting the system;
after that, the control returns to the normal operating system.
Resetting the GDO System is only possible if hydraulic pressure is
available.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
Page 26
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A380 TECHNICAL TRAINING MANUAL
GROUND DOOR OPENING (GDO) SYSTEM
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
LANDING GEARS EXTENSION AND RETRACTION SYSTEM
PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
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General
The Braking Control System (BCS) supplies aircraft retardation during
landing, taxi and in case of a Rejected Take Off.
The nose gear and the aft axles of the body gears do not have brakes
installed.
The braking orders are generated by the auto brake system, the brake
pedals and the parking brake handle.
The BCS has five modes of operation, normal, alternate, emergency,
ultimate and the parking brake.
The yellow hydraulic pressure is used for the Body Landing Gear (BLG)
and green is used for the Wing Landing Gear (WLG).
There are three braking groups: WLG, left BLG and right BLG. Each
group can operate independently in normal, alternate or emergency modes.
Hydraulic power for the alternate, emergency, ultimate and parking brake
is supplied by high pressure accumulators and/or Local electro-Hydraulic
Generator Systems (LEHGS) through the alternate circuit, one LEHGS
for the BLG and one LEHGS for the WLG.
The BCS function is hosted in the Central Processing and Input Output
Module (CPIOM), which controls and monitors the braking.
The Emergency Brake Control Unit (EBCU) controls the emergency
braking.
Brake indications and warning are given by the BCS application hosted
in the CPIOM through the ECAM.
In the following topic, the braking modes will be shown on the BLG.
Braking modes also are applicable to the WLG, except for the parking
brake, which only brakes the BLG. The ultimate braking is different for
the BLG and the WLG.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
Page 28
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A380 TECHNICAL TRAINING MANUAL
GENERAL
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
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Normal Braking
The control of the Braking Control System (BCS) is based on two
redundant systems. Each system has Core Processing Input/Output
Modules (CPIOMs) and Interface Remote Data Concentrators (IRDCs).
The normal braking mode includes the following functions:
- Pedal braking,
- Auto brake,
- Antiskid
- Retraction braking.
The normal braking circuit draws hydraulic power from the centralized
aircraft hydraulic system. Two valves in series are used to control the
pressure in the circuit.
The first valve is an isolation valve, named the Normal Brake Selector
Valve (NBSELV), the valve isolates the hydraulic power supply from
the rest of the braking circuit. The NBSELV is controlled by the CPIOMs.
The second valve is the Normal Servo Valve (NSV) which function is
to control pressure to the demanded level and to supply regulation for
the Anti-Skid function. Each NSV controls the two brakes installed on
the axle.
The NSV is controlled by the CPIOMs via the Interface Remote Data
Concentrators (IRDC).
The auto brake can be used during landing or during a Rejected Take Off
(RTO).
Brakes indications and warning are given by the CPIOMs through the
ECAM.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
Page 30
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A380 TECHNICAL TRAINING MANUAL
NORMAL BRAKING
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
Alternate Braking
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If the normal braking fails, the alternate braking takes over.
The alternate braking mode includes the following functions:
- Pedal braking
- Auto braking
- Anti-skid
The Alternate circuit maintains a similar hydraulic valve layout to the
Normal circuit, with an Alternate Brake Selector Valve (ABSELV) placed
in series with an Alternate Servo Valve (ASV).
The ABSELV is commanded by the CPIOMs and the ASV is commanded
by the CPIOMs through IRDCs.
The hydraulic power is supplied by a Local Electro-Hydraulic Generation
System (LEHGS), which works in unison with an accumulator to meet
the pressure and flow requirements of the Alternate circuit.
A Bogie Shuttle Valve selects the highest pressure from the Normal and
Alternate circuits.
The CPIOMs give brakes indications and warnings through the ECAM.
The triple gage indicator shows information related to the BLG brake
pressures in alternate, emergency, ultimate and parking modes. It shows
in the higher needle the lowest BLG accumulator pressure and in the
lower needles the left and right BLG alternate pressure.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
Page 32
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A380 TECHNICAL TRAINING MANUAL
ALTERNATE BRAKING
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
Emergency Braking
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If BCS function is lost, the Emergency Brake Control Unit (EBCU) is
engaged to control the emergency braking with pedals orders only and
limited braking pressure.
The EBCU uses the alternate hydraulic circuit and controls the ABSELV
and ASV.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
Page 34
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A380 TECHNICAL TRAINING MANUAL
EMERGENCY BRAKING
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
Ultimate Braking
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Ultimate braking supplies braking for the aircraft in the event that pedal
braking is unavailable.
The LEHGS and/or the accumulator power the ultimate braking. Braking
is initiated by parking brake switch action.
The EBCU commands through the alternate hydraulic circuit, a limited
pressure on WLG brakes, when the Flight Control System (FCS) gives
ground spoiler deployment signal.
The Parking brake switch will simultaneously activate the Parking brake
circuit and apply Parking brake pressure on the BLG brakes.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
ULTIMATE BRAKING
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
Parking Brake
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The parking brake function is available only for the BLG wheels.
The Parking Brake Selector Valve (PBSELV) commanded by the park
brake switch is installed in parallel with the ABSELV, and the two
sub-circuits are joined via a Shuttle Valve.
The shuttle valve moves over to let the highest pressure supply the service
lines.
Normal and Alternate braking circuits remain active during and after
application of Parking Brake.
An accumulator re-inflate switch adjacent to the park brake switch
operates the BLG LEHGS and the WLG LEGHS, to pressurize the BLG
and WLG accumulators.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
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A380 TECHNICAL TRAINING MANUAL
PARKING BRAKE
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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A380 TECHNICAL TRAINING MANUAL
BRAKE SYSTEM PRESENTATION (1)
Alternate Circuit Refilling
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The Alternate Refilling Valves (ARVs) are used to replenish the WLG
and BLG accumulators and reservoirs, from the aircraft hydraulic circuit.
There are two ARVs for the BLG, one for the Left BLG and one for the
R BLG, and one for the WLG (Left WLG and Right WLG).
They are commanded open once per flight cycle only, after engine start.
Each ARV is controlled independently by the CPIOMs and is commanded
open if the accumulator pressure is below a defined pressure, or the
LEHGS reservoir is not in the full condition.
In the PARK BRK panel an ACCUS REINFLATE push button is
connected to the WLG LEHGS ECU and to the BLG LEHGS ECU
allowing the BLG and the WLG accumulators re-inflation.
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
Jan 13, 2009
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ALTERNATE CIRCUIT REFILLING
RAMP & SERVICING COURSE - M02 (RR Trent 900) ATA 32 Landing Gear
BRAKE SYSTEM PRESENTATION (1)
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BRAKE SYSTEM PRESENTATION (1)
Brake Temperature Monitoring System (BTMS)
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The brake temperature sensors monitor the temperature of the sixteen
brake packs and send the information to the CPIOMs through LGRDC.
The CPIOMs compute and supply an alert to the flight and maintenance
crew when one or several brake temperatures are outside defined limits.
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BRAKE SYSTEM PRESENTATION (1)
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BRAKE TEMPERATURE MONITORING SYSTEM (BTMS)
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STEERING SYSTEM PRESENTATION (1)
General
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The nose gear and the rear axle of the body gear are steered.
The Nose Wheel Steering (N/WS) and the Body Wheel Steering (BWS)
are controlled and monitored by CPIOMs hosting the Wheel Steering
Control System (WSCS) application.
The N/WS system is powered by the green hydraulic system in normal
operation and from a Local Electro-Hydraulic Generation System
(LEHGS) working in unison with an HP accumulator, for the alternate
mode of operation.
The BWS system is powered by the yellow hydraulic system only.
The CAPT and F/O's hand-wheels, autopilot signals, and rudder pedal
demands control the position of the nose wheels.
BWS commands come from the nose wheel position.
N/WS and BWS commands are reduced as A/C speed increases.
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STEERING SYSTEM PRESENTATION (1)
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STEERING SYSTEM PRESENTATION (1)
Nose Wheel Steering (N/WS)-Normal System
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The N/WS system is powered by the green hydraulic system.
The WSCS function receives the steering orders either from the rudder
pedals, the autopilot, or hand-wheels.
The WSCS controls the Normal Selector Valve (NSELV) and the Electro
Hydraulic Servo Valve (EHSV) to get the nose wheel steering position.
The NSELV isolates the N/WS circuit from the green hydraulic supply
when it works in alternate mode.
The EHSV controls the hydraulic flow to both steering actuators.
Steering indications and warning are given by the WSCS through the
ECAM.
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STEERING SYSTEM PRESENTATION (1)
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NOSE WHEEL STEERING (N/WS)-NORMAL SYSTEM
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STEERING SYSTEM PRESENTATION (1)
Nose Wheel Steering (N/WS)-Alternate System
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If the normal system fails, the alternate system uses hydraulic power from
the LEHGS and the accumulator.
The WSCS controls the Alternate Selector Valve (ASELV).
The ASELV isolates or supplies the N/WS circuit.
There is a Shuttle valve (SV) located down stream of both the NSELV
and ASELV, which controls the supply of hydraulic fluid.
The selected position of the shuttle valve is achieved automatically by
differential pressure.
The Electro Hydraulic Servo Valve (EHSV) controls the hydraulic flow
to and from both steering actuators.
Indications and warning are given by the WSCS through the ECAM.
The Alternate Refill valve (ARV) is opened, if necessary, at the beginning
of each flight to refill the accumulator.
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STEERING SYSTEM PRESENTATION (1)
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NOSE WHEEL STEERING (N/WS)-ALTERNATE SYSTEM
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NOSE WHEEL STEERING (N/WS)-ALTERNATE SYSTEM
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STEERING SYSTEM PRESENTATION (1)
Body Wheel Steering (BWS)
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The main function of the BWS is to increase low ground speed
maneuverability.
The BWS is controlled and monitored by CPIOMs, hosting the WSCS
application.
The BWS interfaces with the CPIOM through the Interface Remote Data
Concentrators (IRDCs).
BWS command is a function of the N/WS angle.
The body wheel steering system is powered by the yellow hydraulic
system.
The BWS Bay Mounted SELector Valve (BMSELV), controls yellow
hydraulic pressure to both the left and right hand BWS.
The left and right Steering SELector Valves (SSELV) are connected
downstream of the BMSELV and isolate the servo metering-valves from
the hydraulic pressure.
The left and right Electro Hydraulic Servo Valves (EHSV), meter the
hydraulic pressure to the actuators.
The left and right Lock SELector Valves (LSELV) are connected to the
hydraulic supply line and isolate the lock actuator from the system
pressure.
Indications and warning are given by the WSCS through the ECAM.
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STEERING SYSTEM PRESENTATION (1)
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BODY WHEEL STEERING (BWS)
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LANDING GEAR MAINTENANCE (1)
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Landing Gear Safety Items
When you work on the landing gear system, make sure that you obey all
the AMM safety procedures. This will prevent injury to persons and/or
damage to the aircraft. Here is an overview of main safety precautions
relative to the landing gear system.
Unwanted electrical or hydraulic power can be dangerous.
When you do any maintenance task, make sure that all circuits are
isolated.
When you tow or pushback the aircraft, you have to be aware that the
aircraft will change its position and can cause injury to persons or kill
them. During towing or pushback you have to keep a safety area of three
meters around nose wheels, towbar and tow tractor.
When you are working on wheels and brakes, not applying the appropriate
procedures may lead to a tire explosion.
Before working on hot wheels and brakes, let them cool, do not apply
gas or liquid on it, and decrease tire pressure before wheel removal.
Movement of landing gear and door can cause injury and or damage.
Before you work on or near the landing gear and door, be sure that the
ground safety device and warning notices are in position.
Some components are heavy; it can cause injury to persons and damage
to equipment.
By consequence, the component removal/installation tasks require specific
tooling that must be used.
Compressed gas is dangerous, it can go through you skin and creates
bubble in your blood and kill you.
High-pressure air and carbon dust can damage your eyes and lungs.
Therefore wear all necessary protection equipments.
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LANDING GEAR MAINTENANCE (1)
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LANDING GEAR SAFETY ITEMS
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LANDING GEAR MAINTENANCE (1)
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LANDING GEAR MAINTENANCE (1)
Landing Gear Ground Support Equipment
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Some landing gear maintenance tasks require Ground Support Equipment
(GSE).
As an example, a GSE used for landing gear maintenance is the wheel
change-jacking tool.
This tool is used to lift the gear during a wheel change.
The A380 requires a specific 137 Tonnes jack spherical with a stroke
limitation of 250 mm. This is to prevent airframe over load at high aircraft
weight above 400 Tonnes.
The A380 jacking dome is type V opposed to the A330/A340, which is
type IV.
Refer to the Aircraft Maintenance Manual (AMM) for the tasks.
Also, refer to the illustrated Tool and Equipment Manual (TEM) for the
complete list of the tools.
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LANDING GEAR MAINTENANCE (1)
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LANDING GEAR GROUND SUPPORT EQUIPMENT
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LANDING GEAR MAINTENANCE (1)
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AIRBUS S.A.S.
31707 BLAGNAC cedex, FRANCE
STM
REFERENCE LAY08521
JANUARY 2009
PRINTED IN FRANCE
AIRBUS S.A.S. 2009
ALL RIGHTS RESERVED
AN EADS COMPANY