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Inhibit transponder auto-on

bobmarkert

bobmarkert

Well Known Member
Is there any way to prevent my Garmin GTX 23 ES transponder (with classic G3X) from turning on automatically at takeoff? I've searched the manual and this forum with no luck. This is a problem when doing formation takeoffs with my teammates and we end up with 3-4 guys squawking within the same formation. Hopefully Garmin has kept this as a user selectable option.
 
See if there is a setting in the install manual not the user manual. If I recall there was a way to disable this function in the GTX327. Of course in my area having this feature enabled helps keep us from forgetting to turn the transponder on which enables the unpleasant feature of making new formation freinds that have live ammo and know how to use it.
 
Capflyer said:
See if there is a setting in the install manual not the user manual. If I recall there was a way to disable this function in the GTX327. Of course in my area having this feature enabled helps keep us from forgetting to turn the transponder on which enables the unpleasant feature of making new formation freinds that have live ammo and know how to use it.
Click to expand...

Yes, the install manual will direct you via the FUNCTION menu how to deactivate the AUTO On feature during takeoff. However, this function should have been deactivated anyway because of the revised transponder usage requirements per AIM. Basically we are now required to turn the transponder ON prior to taxi, and OFF at engine shutdown unless you are in Class G.

Ref. 4-1-20 AIM
3. Civil and military transponders should be turned to the “on” or normal altitude reporting position prior to moving on the airport surface to ensure the aircraft is visible to ATC surveillance systems. IN ALL CASES, WHILE IN CON- TROLLED AIRSPACE EACH PILOT OPERATING AN AIRCRAFT EQUIPPED WITH AN OPERABLE ATC TRANSPONDER MAIN- TAINED IN ACCORDANCE WITH 14 CFR SECTION 91.413 MUST OPERATE THE TRANS- PONDER, INCLUDING MODE C IF INSTALLED, ON THE APPROPRIATE CODE OR AS AS- SIGNED BY ATC. IN CLASS G AIRSPACE, THE TRANSPONDER SHOULD BE OPERATING WHILE AIRBORNE UNLESS OTHERWISE RE- QUESTED BY ATC.
 
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Good point Tom. I wonder if you turn the auto feature off if the transponder will remain in its last setting, such as you had it set to "ALT" before shutting down then does it stay there when starting back up?
 
In Mode-S transponders, GND mode transmits your altitude, and is allowed (and preferred) from "ALT" mode. You do not need to avoid GND mode to be compliant with the AIM.
 
Thanks

90%+ of my flying is with the Renegade Airshow team and 6 of the 10 members are on the same hangar row. We usually do formation departures from a towered airport (KBJC) so when all our transponders come on automatically, tower is not very happy. Once out of the traffic pattern area and we loosen up the formation we get them into STBY except for lead. Turning off the "auto on" feature works best for our situation. Thanks all for the input
 
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Since it is for specific "special occasions", why not wire a switch to "EXTERNAL STANDBY CONNECT"?

You can label it "FORMATION ON/OFF" :)

EXTERNAL STANDBY SELECT (remote STANDBY) is not a momentary input. When EXTERNAL STANDBY SELECT is grounded, the GTX 23 operates in standby mode. In this mode, the transponder will not squitter or reply to interrogations.

Pin 13, but check the latest manual revisions - above is from an unknown on-line version.
 
When flying formation and you're not lead, at startup, simply turn the xpdr to OFF. Problem solved.
 
I don't think that will work with my system , but I'm heading to the hangar soon and I'll check it out
 
scard said:
When flying formation and you're not lead, at startup, simply turn the xpdr to OFF. Problem solved.
Click to expand...

There is no "off" selection with the GTX 23es. Only STBY, GND, ON and ALT.

I have the same issue as the OP. How do we inhibit the GTX 23es from automatically switching from standby to ALT after takeoff?
 
jliltd said:
There is no "off" selection with the GTX 23es. Only STBY, GND, ON and ALT.

I have the same issue as the OP. How do we inhibit the GTX 23es from automatically switching from standby to ALT after takeoff?
Click to expand...

Pull the breaker?
 
TomVal said:
Yes, the install manual will direct you via the FUNCTION menu how to deactivate the AUTO On feature during takeoff. However, this function should have been deactivated anyway because of the revised transponder usage requirements per AIM. Basically we are now required to turn the transponder ON prior to taxi, and OFF at engine shutdown unless you are in Class G.

Ref. 4-1-20 AIM
3. Civil and military transponders should be turned to the “on” or normal altitude reporting position prior to moving on the airport surface to ensure the aircraft is visible to ATC surveillance systems. IN ALL CASES, WHILE IN CON- TROLLED AIRSPACE EACH PILOT OPERATING AN AIRCRAFT EQUIPPED WITH AN OPERABLE ATC TRANSPONDER MAIN- TAINED IN ACCORDANCE WITH 14 CFR SECTION 91.413 MUST OPERATE THE TRANS- PONDER, INCLUDING MODE C IF INSTALLED, ON THE APPROPRIATE CODE OR AS AS- SIGNED BY ATC. IN CLASS G AIRSPACE, THE TRANSPONDER SHOULD BE OPERATING WHILE AIRBORNE UNLESS OTHERWISE RE- QUESTED BY ATC.
Click to expand...

The FAR/AIM is a USA regulation.

Garmin sells into a global market. Imposing FAA standards on non-FAA countries is a bit rude.

In Australia, I want the transponder in SBY 100% of the time when I'm a formation wingman. The only airplane that should be squawking is lead, and sometimes the last aircraft in an extended trail in controlled airspace.

If a transponder is over-riding the command of the PIC in its out-of-the-box configuration, that sounds like a bug Garmin should be expected to fix. An auto-on feature is all well and good, but it shouldn't be the default.

- mark
 
GDU Software 9.10

Good Afternoon,

We are planning to release GDU Software 9.10 next week which will help to correct this behavior when flying formation. If set to STBY prior to takeoff, the system will not automatically transition to ALT when the aircraft becomes airborne, for that flight.

Thanks,

Justin
 
As for turning the transponder off when in formation... Double check ADS-B regulations. For example, the way the rules are written now, it's just about impossible for ferry a plane with inoperative ADS-B, and AOPA is working that problem.

I hope my information is out of date...
 
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