View Full Version : Exact Airbus datalink procedures

4th Apr 2008, 11:20
Can anyone describe to me the exact process of how one would request start-up clearance from somewhere like LHR in an A320 using ATSU/ACARS. I'm absolutely gobsmacked that you can do this, but have absolutely no idea how it works.

Which page of the FMGS would you use? Is there an option merely to type any message you want?

Step-by-step would be great - i'm absolutely fascinated by this little system.

The more I learn about the 'bus, the better I think this wonderful aircraft is.

4th Apr 2008, 15:48
It should be under "preflight" in the acars menu. On ours it says "dep clr": just fill in the blanks and voila!,.
If you dont find it your company is to cheap to buy it...

Jetstream Rider
4th Apr 2008, 15:57
Its not an Airbus thing - we have it on the 757 and 767 and the company operates it on our other types too. We use ACARS, fill in the blanks and get a message back detailing clearance and squawk. Been fitted on the aircraft for years, although LHR has only had the ability in the last year or so.

4th Apr 2008, 23:15
1) So how do you request a loadsheet? What page do you use for this?

2) What's the difference between ATSU and ACARS (except the bloomin' letters!)

3) To print clearances and loadsheets off, do they print AUTOMATICALLY on the A320/330, or is there a special FMGS page for this too? (describe which page if you can pls!)


5th Apr 2008, 12:08

1 You don't(at least we don't) request a loadsheet by ACARS. It is sent by the ops center automatically when it is ready.

2. ACARS is the general system that the aircraft uses to comunicate by datalink. The datalink communication is data that is sent on the back of a radio signal. These are VHF, satellite(UHF) or HF. Within the ACARS system we have 2 kinds of applications, namely ATSU and AOC. They operate off different ARINC standard and hence the difference. ATSU is how we communicate with ATC which is what we know as CPDLC. It also includes DCL(datalink clearance) which is how we get departure clearance from ATC.

The other application(AOC) is the one we use to communicate with the company. It has less stringent certification standard(than ATSU) and that is why it uses a different ARINC standard. Some of the uses include getting weather, atis, free text messages to maintenance, dispatch, etc. It also includes PDC which is pre departure clearance which on the surface is the same as DCL but it is different. With PDC the messages are routed through the company and DCL is direct with ATC. This is transparent to the pilot except for the fact that that a PDC is required by ATC to be read back verbally whereas DCL is accepted on the ACARS with no readback.

From this you can see that a plane can be equiped with ACARS but might not necessarily be CPDLC equiped, in which case it should have no ATSU menu.

3. You can configure anything to print automatically. Press the DATA key followed by LSK 6R(ACARS PRINT FUNCTION) and there you will see a bunch of things you can configure to print automatically(press the right arrow to see more options). Loadsheets always print automatically. I don't know why but it also does not appear in our messages received list(like your sms inbox) so if the printer gets stuck, the only way to re-print is to call ops and ask for another copy to be sent via ACARS.

We are moving to a system where we will print a loadsheet only for info. The actual loadsheet will be accepted by pressing a button on the ACARS.

5th Apr 2008, 23:23
very kind kenny

6th Apr 2008, 00:51
CJ - Airbus have a document 'Getting To Grips With Datalink' that may be useful. I couldn't find it on 'Smartcockpit.com' , but if you want a pdf version, pm me and I will send it. It's about 7.6Mb file.

Dan Winterland
6th Apr 2008, 16:25
There are different ways of doing things dependent on the airline and the airfield. My company uses ACARS for most things now, including the take off perf and the voyage report. But we do have to log on by initialising on the ATSU menu before we can do anything.