CMCS Architecture and Functions Overview
37 Questions
0 Views

CMCS Architecture and Functions Overview

Created by
@LowCostMorningGlory

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What primary function does the central maintenance computer system (CMCS) serve in modern aircraft?

  • Manages fuel efficiency during flights.
  • Controls the aircraft's autopilot features.
  • Offers a central location for troubleshooting and fault reporting. (correct)
  • Provides in-flight entertainment options.

    • Which component is not part of the central maintenance computer system?

  • A printer for hardcopies of information
  • Multi-purpose Control and Display Units (MCDUs)
  • A dedicated autopilot module (correct)
  • A digital computer connected to the CMC

    • How many Multi-purpose Control and Display Units (MCDUs) are typically included in the cockpit?

  • Two or three (correct)
  • One
  • No MCDUs are present
  • Four or five

    • What is the role of the printer in the central maintenance computer system?

    <p>To provide hardcopies of information related to troubleshooting.</p> Signup and view all the answers

    What type of data link system connects the CMCS to transmit information to the home base?

    <p>ACARS (Aircraft Communications Addressing and Reporting System)</p> Signup and view all the answers

    How does the central maintenance computer facilitate troubleshooting in complex aircraft systems?

    <p>By providing a digital computer for each aircraft system.</p> Signup and view all the answers

    In older generation aircraft, how were systems typically tested?

    <p>With individual switches and specific testing methods.</p> Signup and view all the answers

    What is a key benefit of having a central maintenance computer system in aircraft?

    <p>It allows mechanics to troubleshoot in a more economical way.</p> Signup and view all the answers

    Which aircraft systems are typically not connected to the CMC?

    <p>Water system</p> Signup and view all the answers

    In which mode does the CMC scan all aircraft systems and memorize fault information?

    <p>Reporting mode</p> Signup and view all the answers

    What is a common function of the interactive mode in the CMCS?

    <p>Starting system tests</p> Signup and view all the answers

    How many complex systems might typically be connected to the CMC in an aircraft?

    <p>Between 50 and 100</p> Signup and view all the answers

    What does BITE stand for in the context of CMC communication?

    <p>Built-in Test Equipment</p> Signup and view all the answers

    Which component has different names across various aircraft models for the CMC?

    <p>Centralized Fault Display Interface Unit</p> Signup and view all the answers

    What is the maximum number of components in simple systems like the water system that typically are connected to the CMC?

    <p>1 to 5</p> Signup and view all the answers

    How can memorized fault information from the CMC be accessed?

    <p>Via MCDU or a printer printout</p> Signup and view all the answers

    What does BITE stand for in the context of aircraft systems?

    <p>Built in test equipment</p> Signup and view all the answers

    Which of the following is NOT a function of BITE?

    <p>Perform tests when the aircraft is airborne</p> Signup and view all the answers

    What happens to BITE information during the flight if the CMC fails?

    <p>It is lost permanently</p> Signup and view all the answers

    How does a standby CMC function in relation to a normal CMC?

    <p>It receives the same input data and activates automatically if the normal CMC fails</p> Signup and view all the answers

    What is one limitation of the CMC's backup channel?

    <p>It is limited to the interactive mode only</p> Signup and view all the answers

    During which phase does the BITE perform its second function?

    <p>When the aircraft is on the ground</p> Signup and view all the answers

    What components are part of the MCDU?

    <p>Control area with buttons and display area</p> Signup and view all the answers

    Which of the following best describes the MCDU's primary function?

    <p>To control the flight management system mainly during flight</p> Signup and view all the answers

    What is the purpose of the scratchpad in the MCDU display?

    <p>To enter alpha numeric data into the data lines.</p> Signup and view all the answers

    What must be done after typing data into the scratchpad?

    <p>Press the LS key adjacent to the boxes.</p> Signup and view all the answers

    What happens if the data typed in the scratchpad exceeds the allowed value?

    <p>The data entry is not accepted.</p> Signup and view all the answers

    How are the data lines arranged in the MCDU display?

    <p>In 6 pairs with label lines above data lines.</p> Signup and view all the answers

    Which line on the MCDU display is used to show the title of the selected display?

    <p>Title line.</p> Signup and view all the answers

    What does the FAIL annunciator indicate in relation to the MCDU?

    <p>The MCDU is defective.</p> Signup and view all the answers

    What is the primary function of the brightness control knob on the MCDU?

    <p>Adjusts display brightness and switches the MCDU on or off.</p> Signup and view all the answers

    Which of the following is NOT a system shown in the MCDU MENU?

    <p>FMS</p> Signup and view all the answers

    How many line select keys are available on the MCDU?

    <p>12</p> Signup and view all the answers

    What happens when line select key 4 Left is pressed?

    <p>Opens the CMCS maintenance menu.</p> Signup and view all the answers

    What does ACARS stand for?

    <p>Aircraft Communication, Addressing and Reporting System</p> Signup and view all the answers

    What is indicated by the SELECT DESIRED SYSTEM message on the MCDU?

    <p>The user is required to press a line select key to proceed.</p> Signup and view all the answers

    Which of the following abbreviations is specifically for the CMCS in the context of the A340?

    <p>CMS</p> Signup and view all the answers

    Study Notes

    Central Maintenance Computer System (CMCS) Architecture

    • The CMCS is a central system on modern aircraft (A340, A320, 747-400).
    • It provides a standardized method for troubleshooting aircraft systems from the cockpit.
    • CMCS consists of:
      • One or two Central Maintenance Computers (CMC) located in the avionic compartment
      • Two or three Multi-purpose Control and Display Units (MCDU) in the cockpit
      • A printer in the cockpit for hard copies of system information
      • A connection to the ACARS datalink system for transmitting information to the home base
      • A separate digital computer within each aircraft system connected to the CMC for troubleshooting data

    CMCS Functions

    • CMCS operates in two modes:
      • Reporting Mode: Continuously scans connected aircraft systems, recording fault information into memory.
        • This information can be accessed at any time through the MCDU, printed, or sent via the ACARS system.
      • Interactive Mode: Used for system tests only while aircraft is grounded.
        • MCDU allows selecting a specific system and initiating a test.
        • The selected system performs the test and sends results back to the CMC.
        • Results can be viewed on the MCDU, printed, or sent via ACARS.

    BITE (Built-In Test Equipment)

    • Located within each aircraft system's computer
    • Independent of the system's normal operating functions
    • Two functions:
      • Failure Detection: Provides the most probable cause of failures during normal operation
      • Ground Testing: Automatically performs system tests, sometimes including additional tests, when electrical power is switched on (power up test)
      • Manual Testing: Can be initiated manually from the CMC.
    • Test results are sent to the CMC.

    CMCS Redundancy

    • CMCS uses a backup CMC to ensure continued operation in case of primary CMC failure.
    • The standby CMC, which is identical to the primary CMC, receives the same input data.
    • It automatically becomes active when the primary CMC fails.
    • Some aircraft allow manual activation of the standby CMC even when the primary CMC is operational.
    • A backup channel on the CMC provides redundancy for only the interactive mode.

    MCDU (Multi-Purpose Control and Display Unit) Basics

    • Includes a control area with pushbuttons and a knob, a display area (CRT), and annunciator lights for operator communication.
    • Primarily used during flight to control the flight management system.
    • FAIL annunciator indicates a defective MCDU, requiring the use of another unit.
    • Menu pushbutton activates MCDU MENU, displaying connected systems.

    MCDU CMCS Data

    • Displays system abbreviations:
      • FM: Flight Management
      • ACARS: Aircraft Communication, Addressing and Reporting System
      • ACMS: Aircraft Condition Monitoring System
      • CMS: Central Maintenance System (A340 specific)
    • MCDU MENU provides access to CMCS Maintenance Menu for function selection.

    MCDU Display and Data Entry

    • Display has 14 lines, each with 24 characters.
    • Top line displays the title of the selected display.
    • Data lines are arranged in pairs with a label line and a data line.
    • Bottom line (scratchpad) is used for data entry.
    • To enter data, type it in the scratchpad and then press the LS key next to the designated data field.
    • Data is not accepted if it exceeds the maximum length of the data field or allowed value.
    • The CLEAR pushbutton is used to clear the scratchpad.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Aircraft Digital Computer Systems PDF

    Description

    Explore the architecture and functions of the Central Maintenance Computer System (CMCS) used in modern aircraft like the A340 and A320. This quiz covers the system's key components, operating modes, and troubleshooting capabilities to enhance your understanding of aircraft maintenance systems.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser