How many data authorities and ATC units can connect to the aircraft for CPDLC at any one time?
An aircraft can have a maximum of two CPDLC connections established concurrently, each with a different ATSU. Only one CPDLC connection can be active at any given time; any second connection is inactive. [ICAO Doc 10037, ¶ 1.2.
How does CPDLC communicate?
CPDLC is a two-way data-link system by which controllers can transmit non urgent strategic messages to an aircraft as an alternative to voice communications. The pilots are provided with the capability to respond to messages, to request/receive clearances and information, and to report information.
How is CPDLC used in air traffic control?
CPDLC (Controller-Pilot Data Link Communications) uses VHF and SATCOM to transmit Air Traffic Control clearances and messages from the ground to the aircraft, and vice versa. The RTL-SDR dongle (Check Price on Amazon) was originally intended for people to receive TV broadcasts on their computers, but its use has been adapted by very clever people.
How does CPDLC replace voice communications over VHF?
CPDLC also replaces voice communications over VHF relieving the burden on VHF communications which is out of frequencies. FANS Routes allow more direct flights to the destination. Polar Routes allow the aircraft to take advantage of great circle navigation which is a more direct route to countries such as China.
How does flight control communicate with the aircraft?
I read somewhere that control communicates with an aircraft directly, through a direct radio link, while it’s within the line-of-sight. After that control communicates through satellite. Why doesn’t control use satellite throughout the flight? Are direct radio links used only for voice services? or are they used for data as well?
What’s the difference between ACARS and CPDLC messages?
As ACARS messages are transmitted by VHF, HF and SATCOM between the aircraft and airline it means ACARS is available almost anywhere on the planet. CPDLC, on the other hand, is more limited due to the fact the Air Traffic Control area (FIR – Flight Information Region) has to be equipped to handle CPDLC flights.