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3945128218 – Thales ELAC Elevator & Aileron Computer
The Thales 3945128218 is a flight-critical, line-replaceable unit (LRU) that serves as a cornerstone of the fly-by-wire (FBW) flight control architecture for the Airbus A320 aircraft family. Designated as the Elevator Aileron Computer (ELAC), this dual-channel, digital computing system processes manual commands from the cockpit sidesticks, tracking data from the autopilot flight guidance units, and critical inertial/air data parameters. It translates these inputs into real-time, micro-precise hydraulic actuator positioning for the elevators, ailerons, and the Trimmable Horizontal Stabilizer (THS). Operating inside the electronic equipment bay (EEB), the 3945128218 acts as the core mathematical engine driving pitch and roll control while enforcing aerodynamic safety protections to keep the aircraft within its certified structural and flight envelope.
Built to rigorous commercial aviation standards by Thales Avionics, the 3945128218 employs a segregated asymmetric architecture consisting of independent Control (COM) and Monitor (MON) processors. This configuration ensures continuous cross-channel cross-checking to trap data calculation variations or electrical transit faults instantly. The computer integrates inputs from seven distinct aircraft systems, including the Air Data Inertial Reference Units (ADIRUs), Flight Management Guidance Computers (FMGCs), and Radio Altimeters. Each Airbus A320-family aircraft relies on a pair of these computers (ELAC 1 and ELAC 2) acting in a primary/active-backup arrangement to provide immediate, fault-tolerant takeover logic, ensuring uninterrupted pitch and roll authority during normal, alternate, or direct flight control laws.
The Thales 3945128218 is indispensable for maintaining fleet airworthiness, dispatch reliability, and regulatory compliance under recent civil aviation authority updates. As an essential component in Category III Dual (CAT III DUAL) automatic landing operations, this computer must maintain absolute signal and structural integrity to guarantee safety-of-flight during critical low-visibility approaches. For procurement officers, avionics engineering divisions, and global MRO service providers, acquiring this flight-certified, dual-release ELAC ensures perfect integration with existing onboard system buses while eliminating the operational safety risks associated with non-certified rotable hardware.
Key Features
Dual-Channel Asymmetric COM/MON Architecture: Designed with entirely separate Control and Monitor microprocessors executing parallel logic computations to isolate internal hardware anomalies.
Flight Envelope Protection Enforcement: Actively calculates and enforces safety limitations for pitch attitude, high angle of attack (AoA), overspeed protection, and structural g-loading limits.
Multi-Bus Avionics Integration: Seamlessly interfaces with ARINC 429 and ARINC 600 high-speed data bus streams to aggregate inertial, air data, and flight management variables.
Advanced Multi-System Redundancy: Provides automatic master/slave handoff execution between ELAC 1 and ELAC 2, as well as cross-system failover to Spoiler Elevator Computers (SECs).
Ruggedized Modular Avionics Housing: Contained within a standardized ARINC 600 MCU enclosure featuring gold-plated pin insertions, heavy thermal dissipation paths, and structural vibration isolation.
Technical Specifications
Part Number: 3945128218
Component Type: Elevator and Aileron Computer (ELAC) B
OEM Manufacturer: Thales Avionics SA (CAGE Code: F9111)
Chassis Standard: ARINC 600 Enclosure
Internal Architecture: Asymmetric 16-bit/32-bit Microprocessor Core (COM / MON Segregation)
Data Interface Bus: ARINC 429 Input/Output Channels
Input Voltage: 115 VAC / 400 Hz Aircraft Primary AC Bus Power
Cooling Interface: Forced-Air Convection via Avionics Ventilation System
Primary Functions: Pitch Control (Elevators, THS), Roll Control (Ailerons), Normal/Alternate/Direct Law Computation, BITE Diagnostics
Certification Status: Dual Release Eligible (FAA Form 8130-3 / EASA Form 1)
Environmental/Vibration Profile: Certified for harsh electronic equipment bay installations under RTCA DO-160 categories
Software Baseline Compatibility: Regulated under mandatory airworthiness software status (Verify specific load variant such as L103+ / L97+ relative to active regulatory service directives)
Aircraft Compatibility
Airbus A320 Family: A318-100 Series, A319-100 Series (Ceo), A320-200 Series (Ceo), A321-100/200 Series (Ceo).
Note: Final component positioning, airframe tail number effectivity, and active operational software standard compatibility must be cross-referenced and verified strictly against the aircraft's Illustrated Parts Catalog (IPC), Aircraft Wiring Manual (AWM), or carrier-specific Configuration Deviation List (CDL).
Applications
Fly-By-Wire Flight Law Execution: Real-time processing of sidestick deflection variables into direct electro-hydraulic control loop signals.
Autopilot and Autoland Integration: Execution of automatic flight path guidance commands down to CAT III DUAL touchdown thresholds.
Aerodynamic Pitch and Roll Control: Strategic distribution of control surface orders to elevators, ailerons, and horizontal stabilizer jackscrew assemblies.
Why Choose 3945128218?
Sourcing a genuine, flight-certified Thales 3945128218 ELAC is vital to keeping an operator's fleet airworthy and in absolute compliance with global civil aviation directives. Substandard, un-traced, or unrevised rotable units can suffer from severe core memory vulnerabilities, trace degradation, or internal data corruption when exposed to thermal cycling and atmospheric radiation. Such issues risk triggering uncommanded surface deflections or unexpected dropouts into Direct Law, which compromises the aircraft’s structural limits and forces immediate emergency diversions. A certified 3945128218 unit ensures precise timing loops and rigorous Built-In Test Equipment (BITE) isolation compliance, removing the danger of intermittent signal dropouts and securing predictable dispatch reliability across all regional flight legs.
The operational execution of the Thales 3945128218 centers on the principles of asymmetric multi-channel synchronization and digital deterministic control feedback loops. The system relies on a rigorous architectural division where the Control (COM) channel maps and calculates target hydraulic valve deflections based on real-time control law matrices, while the completely independent Monitor (MON) channel evaluates the same flight input metrics using altered algorithmic processing paths. This structural configuration mitigates the threat of common-mode software loop failures. The processing core reads inputs via differential ARINC 429 data links, sampling physical parameters from the ADIRU laser gyros and processing them via discrete Kalman filters to check angular rates against the local gravity vector. The calculated outputs are sent to the main servo-valves via high-frequency pulse-width modulated (PWM) current loops, driving the elevator and aileron hydraulic pistons into precise spatial positions. If any positional delta calculation between the COM and MON hardware pathways exceeds a microsecond tolerance threshold, the unit executes a safe hardware shutdown and transfers command authority to the backup ELAC or SEC bus via high-speed relay de-energization, maintaining absolute aircraft stability and structural integrity.
Note: The Thales 3945128218 ELAC is an ultra-critical, flight-governing rotable electronic component. Component handling, electrostatic discharge (ESD) protective grounding, and system integration testing must be executed exclusively by authorized avionics technicians or certified Part 145 repair facilities. Installation must align precisely with the Airbus Aircraft Maintenance Manual (AMM) Chapter 27 guidelines. Following unit insertion into the EEB rack, a comprehensive flight control computer BITE test and a full landing system test must be successfully passed and documented in the logbook before returning the airframe to revenue service.
Documentation
Airbus A320 System Architecture and Flight Control Specification Overview
No direct public-facing blueprint or raw schematic PDF link is available for this proprietary rotable hardware due to strict intellectual property and aviation security control parameters; all operational wiring paths must be cross-referenced via a licensed Airbus Technical Data Integration portal.
