ACD-57 as Winter 4555 replacement — anyone with real-world Trig TT22 transponder correspondence experience?

[Ward Clapham]

Hi all,

Vancouver Island glider pilot here, flying a Ventus 2b with a Trig TT22 transponder. My Winter 4555 altimeter just failed (tested outside acceptable range), and I'm looking hard at the AIR Avionics ACD-57 as a replacement — but since it's non-returnable once purchased, I want to hear from anyone who's actually run one before I commit.

Specifically:

1. Has anyone installed an ACD-57 alongside a Trig TT22? Did it pass the 24-month altimeter/transponder correspondence check (in Canada we have a 20 ft low altitude tolerance) without drama?
2. Any correspondence drift over time? I don't want to trade one flaky altimeter for another that fails the same inspection down the road.
3. Any install gotchas — static line routing, activation/licensing steps, calibration quirks — that caused a failed correspondence check for you or someone you know?
4. Documentation on hand-off — did your installer/AME have everything they needed (ETSO, static adapter info, etc.) without having to chase the manufacturer for it?

Happy to hear both good and bad experiences — trying to make an informed call rather than find out the hard way at my next inspection.

Thanks,
Ward

[Mark Zivley]

You can control the TT22 with the ACD-57 (requires 2 licenses) and in that situation, the ACD-57 provides altitude information to the TT22.   Seems they should always match since it's the same source for both the altitude display and the transponder.  Only difference is the display allows for adjustment based on pressure vs. 29.92 for the transponder.

[Mark Zivley]

To clarify, the 2 licenses are as follows.   1. for the trig control  2.  altitude display.

[Rakel]

I have an ACD 57 and a Trig TT22. It was tested by my avionics shop and it works just fine. My instruments were tested all the way up to 15,000 feet.