Mode S off on ground
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Mode S off on ground
hello guys, i have the following inquires, why do some airports (berlin) require the mode s to be turned off after parking, my understanding is the ATC specialist (ground/apron controller)can choose what he wants to see.
do you want to see mode s data from an aircraft that is at the gate?
i.e. selected altitude (controller giving atc clearance)
is transpornder code (squak) relevant or required for you to see mode s info at the gate?
i hope my question makes sense other wise I'll rephrase.
thanks very much..
do you want to see mode s data from an aircraft that is at the gate?
i.e. selected altitude (controller giving atc clearance)
is transpornder code (squak) relevant or required for you to see mode s info at the gate?
i hope my question makes sense other wise I'll rephrase.
thanks very much..
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In Australia the requirement is to turn it off once reaching the gate inbound and to turn it on just prior to requesting pushback. At my airport having it on all the time (which a number of internationals do) clutters up the ground radar display and is a bit of a nuisance.
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There are many reasons why it should be switched off, the main ones being:
1) Aircraft ‘tracks’ (the information the controller sees) can erroneously move, even as far as the runway. This of course makes life interesting (e.g. false alarms on runway incursion warning systems etc.);
2) There is also the potential of overloading the TCAS systems of overflying aircraft (which will constantly have to check the Mode S transponders of all of those parked aircraft to verify that they’re still on the ground).
So, best to switch it off
!
Imperator 1300
1) Aircraft ‘tracks’ (the information the controller sees) can erroneously move, even as far as the runway. This of course makes life interesting (e.g. false alarms on runway incursion warning systems etc.);
2) There is also the potential of overloading the TCAS systems of overflying aircraft (which will constantly have to check the Mode S transponders of all of those parked aircraft to verify that they’re still on the ground).
So, best to switch it off
!Imperator 1300
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imperator, now i wonder how the surface movement radar works, if the aircraft target is so unreliable, or do you need the mode A for that.
I place this question:
is the ATC Mode S available to the controller from an aircraft when the ATSU has blocked off?
I place this question:
is the ATC Mode S available to the controller from an aircraft when the ATSU has blocked off?
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MD83FO I am nor sure what an ATSU is but if you mean an ATC tower then the controller does not block anything off, the parameters are set in the equipment.
On the ground your aircraft weight on wheels switch puts the Mode S into Ground Mode. This stops the transponder from replying to air surveillance radars which do not want to see you on the ground, but still allows MODE S surface movements systems such as ASDE-X to track your aircraft on the ground.
The surface system does not want you to squawk at the gate because the proximity of buildings and moving vehicles can cause false tracking to occur. At the same time, if you leave the transponder as it was while flying you are now using an unassigned Mode A code which may have already been reassigned to another flight at the same airport.
Once upon a time leaving the transponder on was used as mitigation against aircrews forgetting to turn it back on and so becoming airborne without TCAS protection; but that was before ground systems that tracked transponders. Another way has to be found to mitigate that problem and I believe most aircraft now have TCAS OFF warnings on the dashboard.
Hope this answers your question
On the ground your aircraft weight on wheels switch puts the Mode S into Ground Mode. This stops the transponder from replying to air surveillance radars which do not want to see you on the ground, but still allows MODE S surface movements systems such as ASDE-X to track your aircraft on the ground.
The surface system does not want you to squawk at the gate because the proximity of buildings and moving vehicles can cause false tracking to occur. At the same time, if you leave the transponder as it was while flying you are now using an unassigned Mode A code which may have already been reassigned to another flight at the same airport.
Once upon a time leaving the transponder on was used as mitigation against aircrews forgetting to turn it back on and so becoming airborne without TCAS protection; but that was before ground systems that tracked transponders. Another way has to be found to mitigate that problem and I believe most aircraft now have TCAS OFF warnings on the dashboard.
Hope this answers your question
