Can you back that up with an FCOM reference? I haven't found anything that supports that view, although it is expressed by some trainers.

Which transponder mode is used depends on the transponder mode switch, which should be in AUTO on the ground. In that case it transmits only in Mode S with the ground flag set, which excludes it from any TCAS and unwanted ATC display. Unlike ON which does indeed switches to Mode S/C regardless if on the ground or not and will usually lead to very fast complaints by your friendly local ATCO.

Setting TCAS to TA/RA does not override the transponder mode selector, try it out next time you're in the aircraft.

Yes, and in effect, uses up bandwidth which is limited. Currently, ATC has to null out the ac on the ground, but the bandwidth is still being used up. With increasing ground ops managing surface flow, it will become critical to turn systems off.

Where are you guys digging this stuff up from? In Australia (unless we are way out in front of everybody else), it's TCAS on TA/RA on receipt of Airways clearance ie before start, and TCAS OFF when you shut down the donks.

Bandwidth overload, maxxed out SSR?? :confused:

Hey Bloggsy.......we go further, the TCAS switch is never touched out of the TA/RA position unless directed by a non normal checklist or possibly if you desire during a PRM app in SYD to TA.

The Transponder is switched to Auto before start and back off after shutdown. Turning off the Txpd shuts down the TCAS at the same time.

Besides, in the AUTO mode the TCAS is inhibited on the ground anyway.

TCAS is not inhibited on the ground, it is in ground mode (not causing RAs).
But Mode A and C will be active.
We used to keep TCAS on before, but some years ago there was a request by ATC here in Europe to PLEASE keep it to mode S on ground only.
It is also in almost any airport briefing here.
I will try to dig out the respective notice.

ACAS Guide Airborne Collision Avoidance Systems (incorporating TCAS II versions 7.0 & 7.1 and introduction to ACAS X)
May 2016

p.42 INTERFERENCE LIMITING
p.70 TCAS II/TRANSPONDER OPERATIONS ON THE GROUND

The techical explanation is not provided in that particular document, but guidelines are very clear.

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And a leaflet straight out of my flightbag, where a copy is stored for no apparent reason since 2004. :E

This brochure describes transponder operating procedures from departure gate to runway line-up, and landing to gate.

Full dedicated webiste here:
EUROCONTROL Documents on SSR Mode S | Eurocontrol

Bloggs, time to evolve. If and when AUS adds ground ops, or the airspace gets closer to capacity, you will begin to see the same.

Thanks for once again, trolling my posts! I have a stalker!

A-SMGCS in operation at YMML, YSSY with TCAS/transponders going full bore. Obviously no bandwidth issues there. Stop making grandiose, sweeping statements that don't apply everywhere.

As this is a thread about the airbus TCAS, do you have any official documentation that actually confirms that? I haven't found any, and testing it with our local ATCOs actually confirmed that mode A/C are not active on the ground with TCAS on. That said, that is not official confirmation of course.

Just weird that on my previous type it was actually the OEM that changed our SOPs after a fleet audit at "my" outfit to always have TCAS on instead of switching it off and on. According to the OEM all that achieved was wearing out the switch. No complaints from any ATC unit and we are a medium sized legacy carrier in the middle of europe.

I can't recall the exact reasons given but for 6 months we selected the TCAS ON before line up and OFF after vacating. That lasted 6 months until our Fleet Tech office determined that the TCAS systems fitted were updated to the latest software/mod and we can leave it switched on all the time.

Now, as per Airbus standard, we switch the TXPDR to SBY at the gate.

A330.

While the comments are for operations where there are issues, why do you continue to comment on areas where there are not issues? As noted, IF and WHEN AUS adds ground ops, there will be bandwidth issues, like at other locations where they have.

Again, time to READ, evolve, and stop stalking, stop inserting yourself where you are irrelevant.


Did you figure out that Perth only has one AWOS, and when you get TCH winds, it is simply because they give the winds per runway end with the corresponding headwind/tailwind component? Or do you really think they measure they winds at each TCH?

Mate if you don't want others to comment on your posts then...............don't post.