Educational familiarization only. This original TechOpsBase resource explains system purpose, architecture and maintenance reasoning. It does not reproduce Airbus pages, diagrams, procedures, limits or controlled maintenance data. Actual aircraft work requires current approved data, correct effectivity, operator procedures, authorization, safety precautions and supervision.
Resource profile
- Aircraft: Airbus A350 family
- ATA chapter: 32 — Landing Gear
- Audience: Students, junior technicians and working professionals
- Level: Intermediate familiarization
- Source basis: Privately supplied legacy manufacturer training and MSG-3 material
- Technical status: Draft pending technical review
Learning objectives
- Trace normal brake command flow.
- Explain anti-skid feedback.
- Describe autobrake integration.
- Explain pressure control and reconfiguration.
- Apply wheel-group fault reasoning.
1. Brake demand
Normal braking can begin with pilot pedal input or an automatic braking command. The Brake Control System combines demand with aircraft-state, wheel-speed, steering and protection data to determine the pressure required at each brake group.
The command is electronically computed and hydraulically executed. A braking complaint can therefore originate before the hydraulic valves, within pressure modulation, at the brake, or in the wheel-speed feedback.
2. Anti-skid
Anti-skid compares wheel behavior with a reference and reduces pressure when a wheel approaches an excessive slip condition. It continuously balances stopping performance with tire/runway adhesion.
A faulty wheel-speed channel can remove or degrade anti-skid for the affected wheel or group. Troubleshooting must distinguish an actual wheel deceleration event from sensor, drive, wiring or computation faults.
3. Autobrake and protective logic
Autobrake applies a selected deceleration strategy when engagement conditions are satisfied. The system can disarm when pilot inputs, faults or aircraft-state changes make automatic braking inappropriate.
Brake-release logic can reduce braking during tight pivot turns at high steering angles, protecting tires and improving maneuvering. This illustrates how braking and steering systems exchange data.
4. Hydraulic execution
Selector and pressure-control valves route and meter the normal hydraulic supply to the wheel brakes. Pressure limitation protects components while feedback and monitoring identify failures or command/response disagreement.
When normal capability is lost, the system may reconfigure to alternate braking. The correct maintenance question is not only whether pressure exists, but whether the intended control mode and protections are available.
Maintenance boundary
This lesson supports system understanding and maintenance reasoning. It deliberately excludes task steps, numerical limits, servicing quantities, torque values, dispatch decisions and configuration-specific instructions. Before touching the aircraft, confirm the current approved maintenance data, aircraft effectivity, safety procedures, tooling, personnel authorization and restoration requirements.
Review prompts
- What is the commanded function?
- Which computer or control channel accepts the command?
- Which energy source performs the movement or braking action?
- Which mechanical locks, valves or actuators must change state?
- Which sensors confirm that the commanded state was achieved?
- What independent or alternate path remains available?
- What hazards exist if maintenance personnel assume the indication alone proves the system is safe?
