Air on Ground ADS-B faults

[One Whiskey Hotel]

Anyone else get a call from FAA about ADS-B issues? My initial issue dealt with an easy fix (length/width code error, a misconfigration). Once I called the inspector about that issue, he went into the minuscule issue of air on ground faults, which I understand are inevitable on takeoff as the airplane accelerates past stall speed but is not yet airborne.

High speed taxis can cause this too I’m told, and manually switching from ‘On’ to ‘Altitude’ can prevent this one, at least long enough to get an inspector out of your hair, but how can these be ironed out entirely so this guy quits bothering me? 

I’m assuming when 2020 comes, being on their hotlist could Ground me for ADS-B, so I’d like to get this put to bed well in advance.

Anyone else have similar experience and insight to a fix? Can setting the stall speed a little higher in the configuration menu ‘force’ the fault to correction?

[Cruiser]

I would suggest you get the avionics installer involved. They should be responsible for the proper configuration and assure correct operations. 

[N201MKTurbo]

What are you using for your air/ground indication? I'm using the output from the Avidyne and it is displayed on the transponder. Do you have any way of displaying its state?

[PaulM]

I don't think 1WH was having problems with his air/ground system, just that the FAA inspector talked about what they saw as an issue. 

What pilots saw during the rebate period is that the FAA's automatic remote evaluation of air/ground status often did not agree with the reported status from the ADSB transmitter.   FAA's evaluation was all about GPS coordinates.  Air/ground can be a squat switch, WOW, airspeed, or computed by the GPS.

The heart of the issue is that the FAA remote evaluation is generic.. one size fits none..   If they tailored the in-flight, on ground speeds to each aircraft type it would be closer... In the end only the actual performance of the individual aircraft/transponder pair  matters.  The FAA won't be flagging people for this parameter unless it is obviously very wrong.. (shows on ground at 100+ knots)  transient false positives  are to be expected if they use a generic envelope.