Use of transponder on the ground

[roundwego]

I thought it would be easy to find a reference to the correct protocol regarding the use of transponders on the ground.
Obviously at SMGCS equipped airports, aircraft transponders should be switched on before pushback/taxi until back on stand but what about airports where no such equipment is used?
My company's procedure at a non SMGCS airport (99.9% of our ops) is to switch it on just before line up and switch it off after vacating the runway but is this "best practice"?
Ideally, I would wish to switch it on before taxi and off just before shut down purely because it is one less thing to do while taxiing but is there a CORRECT answer? Please provide a reference if possible.

[Minesapint]

Try the Eurocontrol site www.eurocontrol.int/msa and search for TCAS. If you have a problme, PM me.

[roundwego]

Minesapint,

Appreciate your suggestion but I waded through the eurocontrol site as far as I could without drowning and couldn't find an answer.

[Imperator1300]

Roundwego,
Perhaps have a look here:
www.eurocontrol.int/airports/public/standard_page/APR1_Projects_ASMGCS.html
There is a leaflet outlining the procedures somewhere on the page and as far as I know they can be applied at any airport (whether A-SMGCS equipped or not).
Imperator1300

[MrApproach]

Its about TCAS and the transponder. With A-SMGCS (SMGCS is just the paint, guidance signs etc) the Mode S transponder should be on and in ground mode, when on the ground, normally achieved through a weight on wheels switch. If no squat switch then there should be a cockpit air/ground mode switch. Eurocontrol would like the TCAS switched off when you are on the ground because it acts as a transponder interrogator and if enough aircraft are present eg Heathrow, Frankfurt etc, can electronically swamp the terminal area. Europe has presented rule changes to ICAO for changes to the way transponders/TCAS are operated. If you have Mode A/C it does not have a ground mode so you should check local requirements as Mode A/C transponders can generate false radar tracks on ATC radar. If you are at an airport without A-SMGCS the procedure probably should be the same but only for cockpit procedure reasons. The issues about false tracks could still be a problem.
In summary:
Taxi - Take off, Mode S on in ground mode, TCAS standby/Off, Mode A standby,
Take Off - Landing , TCAS on, Mode S air mode, Mode A/C on
After landing, TCAS off, Mode S on in ground mode, Mode A/C off.
All of this is on the Eurocontrol website, ASMGCS pages.

[Spitoon]

There is a [Eurocontrol] leaflet outlining the procedures somewhere on the page and as far as I know they can be applied at any airport (whether A-SMGCS equipped or not).I don't know whether the leaflet is still available or has been updated but I heard talk recently that suggested the mode A conspicuity code for mode S equipped aircraft was now to be 2000 rather than 1000 as had been promoted previously by Eurocontrol.

[A7700]

The legal references are only in the "tubes" :
The European Air Navigation planning group ( from ICAO) has agreed for the changes proposed by Eurocontrol in order to use A-SMGCS level 1 and 2. It has taken one year more because some airlines refuses to change their (unnecessary) routine TCAS procedures.
For the existing A-SMGCS The present use of data's is mainly done through a discrete code (Mode A) and FPL correlation using mode S squitter on the ground ( Conspicuity code will be for the future developpement, and as said and requested by the Eurocontrol Mode S Unit , 2000 instead of 1000 reserved for the airside for the time being - waiting for more trust in the system...)
The changes are expected to be published 1st quarter 2008 :
In DOC7030 (Only for the ICAO EUR Region, decision by Montreal) , to the equivalent of DOC4444 chapter 7 and 8 for the ATC procedures part
in PANS-OPS (DOC8168) for the mode S and TCAS changes on the crew side
All the procedures have been coordinated with the FAA. The new handling of Mode S XPDR + TCAS is independant of the ground equipment:
Mode S XPDR shoud be ON when requesting taxi or push so that the identification of the aircraft should appear just at clearance request (Not before in order to not overloaded the surveillance screen) and should be kept after landing until the gate ( When at the gate , should be switch off so that the Mode A code could be re-use for another aircraft)
TCAS should be put ON only when lining up and OFF when vacating the runway in order to avoid unnecessary interrrogations between TCAS on the 1090 Mhz band, resulting in busy environment, into a lost of SSR track on the ATC airside surveillance display). When the ACAS requirements where defined, no one of them was taking care of a ground usage: "A" is for Airborne and so indications when TCAS is used on the ground can be completely wrong.
A7700 , member of the project team

[Minesapint]

PANS ATM is about to be changed for 2000, its for aircraft not receiving an ATC service basically. I can post the whole thing if needed. 1000 will remain the Mode S conspicuity code.