Transponder
Transponder
Greetings
I have a question as an ATC with regard to transponder information. My facility sees Mode A, S and ADSB and will display on our screens if we see any of those three. My question is that on the case of an aircraft with mode S and ADSB equipped is the physical method for inputting the call sign done in more than one place. Do you input a call sign on the mode S transponder and the ADSB machine? Do you input the call sign into a separate panel that covers both?
I ask the question because when the S or ADSB don't match the A we get an indication. Our system uses the A for coupling of tracks so you are tagged up correctly with the flight plan call sign. I want to know what is the most correct way of asking an aircraft to rectify the issue. Currently I say something like 'either your ADSB or Mode S is giving incorrect ident, could you check and set it to ABC123'
Do I need to specify the either/or part of the message?
I have a question as an ATC with regard to transponder information. My facility sees Mode A, S and ADSB and will display on our screens if we see any of those three. My question is that on the case of an aircraft with mode S and ADSB equipped is the physical method for inputting the call sign done in more than one place. Do you input a call sign on the mode S transponder and the ADSB machine? Do you input the call sign into a separate panel that covers both?
I ask the question because when the S or ADSB don't match the A we get an indication. Our system uses the A for coupling of tracks so you are tagged up correctly with the flight plan call sign. I want to know what is the most correct way of asking an aircraft to rectify the issue. Currently I say something like 'either your ADSB or Mode S is giving incorrect ident, could you check and set it to ABC123'
Do I need to specify the either/or part of the message?
On the A330 and 777 the flight number is put into the FM/FMC * during the setup preflight.
Input is in the usual XXX123 format.
We must put it in correctly as it won't logon to CPDLC if it's wrong ( been there and done that!! )
So ask them to confirm their ident is correctly entered on their FM/FMC
The Transponder has the code given to us by you. The ADS B out function transmits all the data ( pre programed and some stuff from the FMC I think ) free to air from the transponder, we don't have any means to input data into the transponder apart from the discrete code.
* FM Airbus speak for Flight Management
* FMC Boeing speak for Flight Management Computer.
Basically the same thing.
Input is in the usual XXX123 format.
We must put it in correctly as it won't logon to CPDLC if it's wrong ( been there and done that!! )
So ask them to confirm their ident is correctly entered on their FM/FMC
The Transponder has the code given to us by you. The ADS B out function transmits all the data ( pre programed and some stuff from the FMC I think ) free to air from the transponder, we don't have any means to input data into the transponder apart from the discrete code.
* FM Airbus speak for Flight Management
* FMC Boeing speak for Flight Management Computer.
Basically the same thing.
Last edited by ACMS; 16th Jan 2015 at 06:38.
Later installations typically allow the flight ID to be typed into the FMS. Some which originally didn't include Mode S have a separate way of "dialling" it in at the transponder.
I think in virtually all cases the ADS-B data is directly derieved off the Mode S data, so I don't think you will find aircraft with a seperate means to define it.
ADS-B is a subset ("extended squitter") of Mode S anyway.
I think in virtually all cases the ADS-B data is directly derieved off the Mode S data, so I don't think you will find aircraft with a seperate means to define it.
ADS-B is a subset ("extended squitter") of Mode S anyway.
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Usually what i get from ATC is either "please squawk xxxx" if the incorrect squawk is set and "please correct your flight id to.." if the wrong callsign has been entered into the FMC. On quite a few sectors all aircraft use the same squawk (1000) anyway so the flight id is getting more important.
The controller can't tell of you've entered the wrong format for the flight number in your FMC. On more than one occasion over Oz I've heard quite a VHF exchange going on to workout why the CPDLC won't connect. Only after quite a few calls did they workout it was the flight number incorrectly entered in the FMC causing the failure to logon.
Problem fixed
The logon is initiated by the Aircraft not the controller, hence the secure connection never works if the data is wrong from the Aircraft and the controller cannot see what the problem is.
Problem fixed
The logon is initiated by the Aircraft not the controller, hence the secure connection never works if the data is wrong from the Aircraft and the controller cannot see what the problem is.
Both the Mode S Flight ID and the ADS-B ACID come from the same register in the transponder, so if one is incorrect then the other will be too.
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On the 744/748 there are 2 places to input the call sign -- on the ACARS INITIAL DATA page and the FMS ROUTE page. IIRC, the former goes to ADSB/Mode S, and the latter goes to ADS-C/CPDLC/ATC Comm.
I'm not sure the CPDLC gets it's flight number data from the ACARS.
I've flown both the 777 and the A330 with inop ACARS and the CPDLC still worked and had the correct data.
The ACARS is only for company comms/ admin stuff/wx etc
The FM or FMC sends the data to and from the CPDLC ADSB units directly irrespective of ACARS.
( yes I agree it also sends data to the ACARS as well )
I've flown both the 777 and the A330 with inop ACARS and the CPDLC still worked and had the correct data.
The ACARS is only for company comms/ admin stuff/wx etc
The FM or FMC sends the data to and from the CPDLC ADSB units directly irrespective of ACARS.
( yes I agree it also sends data to the ACARS as well )
