ATA22

Overview

  • This document serves as a technical training manual for the Airbus A319/A320/A321 Auto Flight system, focusing on Mechanical and Avionics aspects related to the PW1100G engines.

General Information

Document Usage

  • Designed for training purposes only.

  • Not to be used as a reference guide; no updates will be provided.

  • Reproduction of content is prohibited without written permission from Airbus S.A.S.

Environmental Considerations

  • Users are encouraged to consider the environmental impact before printing the document.

Auto Flight System (AFS) Details

Introduction to AFS

  • The Automatic Flight System (AFS) enhances pilot workload management and flight safety.

  • Provides functions to assist in reducing landing distances and includes:

    • 2 Flight Management and Guidance Computers (FMGCs)

    • 2 Flight Augmentation Computers (FACs)

    • 2 Multipurpose Control and Display Units (MCDUs)

    • 1 Flight Control Unit (FCU)

Functions of AFS

  • Break Distance Calculation: AFS computes real-time braking distances to anticipate overrunning risks during landing.

  • Data Exchange Examples:

    • Receives altitude and attitude data from the Air Data/Inertial Reference System (ADIRS).

    • Transmits autopilot orders to ELevator and Aileron Computers (ELACs).

Components and Controls

Flight Management and Guidance Computers (FMGC)

  • Composed of:

    • Flight Management (FM) section: handles flight plan definition and monitoring.

    • Flight Guidance (FG) section: manages aircraft control functions.

Flight Augmentation Computer (FAC)

  • Basic functions include:

    • Yaw damper control

    • Rudder travel limitation

    • Flight envelope protection

Control Panels and Interfaces

Flight Control Unit (FCU) and MCDUs

  • FCU: Short-term control device for engaging autopilot and other flight management functions.

  • MCDUs: Provide long-term control and interface between crew and FMGC, allowing management of the flight trajectory.

Autopilot Functionality

  • Engagement:

    • Initiated from FCU using related pushbuttons.

    • Engagement status indicated on the Primary Flight Displays (PFD).

  • Modes: Includes take-off, cruise, and landing modes, engaging different control systems accordingly.

Flight Guidance Systems

Autothrust Function (A/THR)

  • Engagement: A/THR can be engaged manually or automatically under specific conditions.

  • Thrust Control: Adjusts according to the calculated thrust target from FMGC.

Alpha-Floor Protection

  • Protects against excessive Angle-Of-Attack (AOA) by commanding maximum thrust under critical conditions.

Maintenance and Fault Detection

Fault Isolation and Detection System (FIDS)

  • Centralizes failure detection and maintenance information from various AFS components.

BITES (Built-In Test Equipment)

  • Each AFS component has associated BITES to perform ongoing health checks and report faults.

Navigation Backup System

MCDU Backup Navigation (B/UP NAV)

  • Activated when both FM parts fail, providing essential navigation data for crew member use based on inertial reference systems.

Conclusion

  • The A319/A320/A321 Auto Flight Technical Training Manual is a critical resource for understanding the aircraft's automated flight systems, their controls, functionalities, and maintenance considerations.