Having it explained to me briefly what exactly the tower does that cannot be handled by such a system would probably enlighten me somewhat.
Fair warning, that's my job you're trying to replace with a computer, so I'm probably biased. Still though, hear me out:
What do we do?
Handle a large amount of non-standard requests and communication between the ...
The current air/ground systems (based on OSI) are aviation unique. And they are limited by design to "messages no larger than 3.5 kilobytes". This limits how much information can be sent to/from an airplane, and is a major roadblock towards time based navigation and the broader data-hungry Global Air Navigation Plan (GANP), which includes SWIM for ...
Short answer: it's coming soon.
For why can't they, the answer is limited data transfers at the moment, which is being worked on.
See: How can shifting to TCP/IP make current aviation systems more delay-tolerant?
Once implemented, it will be like the current CPDLC, where an instruction awaits the crew to press accept, reject, or cancel. A plane like the ...
It's already here, but it's private
Your proposed geostationary orbits are very high, and since aircraft are the transmitters, that means high power antennas are required from the aircraft.
However, low Earth orbits (LEO) are more forgiving. By using 72 ADS-B receiver-equipped satellites in LEO (icao.int), Aireon will provide 100% global coverage by Q3 ...
ADS Broadcast and ADS Contract are intended for different purposes. They use the same type of equipment except for the link technology, which is matched to the differing intent.
ADSB is intended to allow self separation between aircraft as well as for informing ground control of position, as a radar would. It is a predetermined set of messages that are ...
Someone said FANS includes CPDLC, another said it does not.
It depends on the region and/or airplane generation.
There is the ICAO-compliant CPDLC used in Europe (via ATN-B1), and there is the Oceanic/US CPDLC (via ACARS).
A plane fitted with FANS 1/A+ has the Oceanic/US CPDLC, but not the European one.
New long-range planes like the 787 and A350 use FANS ...
That pic is from "the Naval Air Warfare Center, Weapons Division (NAWCWD)"
So, testing and development.
Possible reasons (purely speculative):
Testing capability/performance from the 2 different wing stations.
Test/compare different software configs in each.
Ferry one to somewhere else.
In your question, you're mixing two things about aircraft communications:
The protocol used by the satellite transceiver aboard the plane (SDU) to communicate with the its ground station (GES). It allows for example to log on/off with the satellite service. This protocol is a custom one.
The protocol used by engines and other aircraft systems to ...
A, B, and C are the names used by Airbus. As a short summary:
If you want text communication with ATC (CPDLC), you need FANS A in USA/oceanic, and FANS B or C in Europe.
If you want position/trajectory reporting at set intervals (ADS-C) in continental Europe, then you need FANS C (still being tested).
See the Airbus slide below for more:
With most airlines, the PM(pilot monitoring) handles datalink communication, with confirmation from the PF(pilot flying) before executing any instructions, clearances, or changes.
As with everything, there might be some exceptions at some airlines.
Because the pilot in command of the flight is responsible for the safe outcome of the flight, not air traffic control. Pilots are responsible to evaluate a clearance and accept or decline it. Controllers have very limited information on a flight's situation and circumstances, information the pilot(s) must be aware of and must take into account in accepting a ...