Equipment & Systems - FMS & CPDLC

Question 1

What is CPDLC?

Answer 1

Controller Pilot Data Link Communications

CPDLC is a data link application that allows for
the direct exchange of text- messages between
controller and pilot.

Question 2

CPDLC - dos the pilot have to acknowledge a read back?

Answer 2

No

Question 3

CPDLC requires SPECIFIC readback of clearances, true or false?

Answer 3

FALSE

Question 4

What contents are in CPDLC messages? (6)

Answer 4

• FLs
• lateral deviations
• route changes
• clearances
• routing delveriry of messages
• crossing contracts

Question 5

What are the benefits of CPDLC?

Answer 5

• Allow flight crew to print messages, to give better understanding to foreign pilots.
• Allowing auto load of specific uplink messages into the FMS reducing crew-input errors.
• Allowing crew to downlink complex route clearances and requests, which ATCO’s can re-send when approved without having to type a long string of coordinates.
• Specific uplink messages arm the FMS to automatically downlink a report when an event (such as crossing a waypoint) occurs. This automation assists with workload management for all.
  Some messages will automatically update the Flight Data Record (FDR) in some ground systems.

Question 6

What is CPDLC Emergency Mode?

Answer 6

The sending of a CPDLC MAYDAY message automatically places the CPDLC and the ADS functionality into Emergency Mode.
The crew can also select ADS Emergency Mode
independently of CPDLC.

Question 7

Who can turn off and on CPDLC Emergency mode?

Answer 7

Emergency Mode can only be initiated by the crew and can only be cancelled by the crew

Question 8

What is FMS?

Answer 8

Flight Management System

Question 9

What are the Components of FMS?

Answer 9

FMC (Flight Management Computer)
AFS (Auto Flight System) (Auto Pilot)
Navigation System
- IRS (Inertial Reference System)
- GPS.

(EFIS Electronic Flight Instrument System is not an FMS component, though it is an important interface between FMS and pilots)

Question 10

What is ACARS?

Answer 10

Aircraft Communications, Addressing and Reporting System

Question 11

How is ACARS used?

Answer 11

ACARS uses the AM mode because the same airborne VHF radio is often also used for voice communications.
Burst transmissions are used with a limit of 220 characters per message.
Transmissions often last less than one second!

Question 12

What 3 types of ACARS messages are there?

Answer 12

Air Traffic Control (ATC)
Aeronautical Operational Control (AOC)
Airline Administrative Control (AAC)

Question 13

What can the ATC part of ACARS be used for?

Answer 13

• Pre-Departure (Clearance delivery)
• Datalink ATIS
• En-route Oceanic Clearances

Question 14

What can the AOC & AAC part of ACARS be used for?

Answer 14

• Upload of weather or NOTAM information;
• Download from the aircraft of status, position, eta, and any diversion;
• Download of spot weather observations from aircraft sensors;
• Download of technical performance data including automatically triggered exceedance or abnormal aircraft system status information;
• ‘Housekeeping’ Information such as catering uplift requirements, special passenger advice and ETA.
• Free Text messaging is also possible.

Question 15

What are the benefits of ACARS?

Answer 15

• It automatically sends messages about each phase
  of flight OOOI msgs (out of the gate, off the
  ground, on the ground, and into the gate).
• Information on aircraft systems in real time.
• Interfaces with the FMS system for flightplans and
  weather information.
  It utilises VHF, HF and in some cases Satellite links.

Airline use mostly