Help---unable to get ADS-B rebate due to error Garmin says in no big deal

murphey said:
There's a lengthy discussion about this over on MooneySpace. I just came back from my verification flight - passed everything EXCEPT the "Air on Ground" flag. With this many people having the exact same problem with different aircraft and different shops in different states, the shop is not the problem, Garmin is the problem.
Click to expand...


What I did was left the transponder off till at the hold short line, then turned to stanby. Do not move the airplane till its completely booted and no warnings are flashing. Entered the code and then turned to mode C. Then taxi into position slowly and takeoff. Landng was similar, I stopped on the runway breifly before taxing slowly off the runway then shut the transponder off after stopping on the ramp.

Its possible that it is not configured properly and thinks it has a discrete connected when it doesn't.
 
Last edited:
bnt83 said:
What I did was left the transponder off till at the hold short line, then turned to stanby. Do not move the airplane till its completely booted and no warnings are flashing. Entered the code and then turned to mode C. Then taxi into position slowly and takeoff. Landng was similar, I stopped on the runway breifly before taxing slowly off the runway then shut the transponder off after stopping on the ramp.

Its possible that it is not configured properly and thinks it has a discrete connected when it doesn't.
Click to expand...
Will give it another try tomorrow morning with your instructions. Wasn't planning on it, tho. Getting too hot, too early in the morning. Too windy at night. Sent a note to the shop asking if they've seen this and if they have any suggestions.
 
murphey said:
Will give it another try tomorrow morning with your instructions. Wasn't planning on it, tho. Getting too hot, too early in the morning. Too windy at night. Sent a note to the shop asking if they've seen this and if they have any suggestions.
Click to expand...

Was the % error high on the report? That might be a clue as to whether or not its configured properly.
 
bnt83 said:
Was the % error high on the report? That might be a clue as to whether or not its configured properly.
Click to expand...
Very low %, waiting for a response from the shop.
 
The Ground/Airborne fail sounds a lot like a mis-configuration of your system.

I had a similar problem with a Bendix/King KT-74 tied to a Garmin 430W. To get the rebate I switched from Standby to Altitude on the take-off roll, then called the local Class "C" tower and told them I needed to fly circles around the tower above the class C for 30 minutes. After landing I switched back to standby on the roll out.

The REAL problem was the shop did not configure the new transponder! After several attempts I managed to acquire a copy of the STC for the installation and set the "Squat Switch / Airspeed Switch" parameter correctly. Now everything works well.

The transponder should have an indicator for "GND / ALT" or something similar. This would be the tip off for a mis-configured "Squat Switch / Airspeed Switch".
 
Last edited:
denverpilot said:
Oh. Did they test fly it, or you? I got the impression you were doing test flights.
Click to expand...
Me. The 2 hr flight home didn't count because I didn't do enough climbs/descents/360s. The one yesterday got the Air on Ground errors. Need to do another one tomorrow using the suggestions here.

Had to wash it when I got home because it was sitting on the ramp for over a week. Glad I took the sunshades along.
 
I wonder if the air-ground errors are worse at some airports than others. If its calculating a determination of air/ground would it need to know what the GPS elevation of the airport is? I think there are variables in accuracy of the data points and why these fail intermittently when checked.
 
Seems like guys have problems mostly with interracial marriages - i.e., Aspen to Garmin etc. . .

I upgraded my 530 to a 530w and a 330 to a 330ES and first flight home qualified me for the rebate. . .
 
bnt83 said:
I wonder if the air-ground errors are worse at some airports than others. If its calculating a determination of air/ground would it need to know what the GPS elevation of the airport is? I think there are variables in accuracy of the data points and why these fail intermittently when checked.
Click to expand...

I believe, the "Air / Gnd" is determined by a squat switch or an airspeed switch. For my ADS-B installation the STC calls for an addition of an airspeed switch, set for about 35 knots, which connects to the transponder squat switch input. The transponder configuration uses the "Squat Switch" setting to determine if you are on the ground or off the ground.
 
I just finished the THIRD attempt at the validation flight. Got this in the email:

"Your Performance Report request for Tail Number N2127R on 7/09/2017 failed to generate a result."

Swell. Just swell. I sent off a comment to the ADSBRebateHelp line pointing out that I've already spent $400 getting the airplane to/from the avionics shop and another $200 on the three failed validation flights and I'm fed up.

I turned it from standby to alt before I took off. It's night time and the buttons are NOT lighted! I had to turn on the ceiling light to make the changes, change the code (Denver center is very accomodating at 10 pm at night, 'specially when FTG is 5 nm from DIA)

So is Garmin going to get the fix out to everyone before the rebate deadline? And how is it going to be installed? By magic? I'm not going to fly 4 hours RT to the shop for the software update.

Just got the automated response from my request about the failed attempt:
"Thank you for contacting us. Please allow 3-5 business days for us to reply to your request."

grump grump grump grump grump.
 
murphey said:
Swell. Just swell. I sent off a comment to the ADSBRebateHelp line pointing out that I've already spent $400 getting the airplane to/from the avionics shop and another $200 on the three failed validation flights and I'm fed up.
Click to expand...

Hmm. Methinks I have another reason not to care about the rebate now.

And I'm thinking this isn't all on Garmin.

Who certified Garmin's stuff? Oh yeah. FAA.

The installation methodology and everything... all certified by the same folks who are saying yours isn't doing what they want it to do.

And why a flight test anyway? If the system can't be tested on the ground, it shouldn't be flying anyway.
 
A1Topgun said:
I believe, the "Air / Gnd" is determined by a squat switch or an airspeed switch. For my ADS-B installation the STC calls for an addition of an airspeed switch, set for about 35 knots, which connects to the transponder squat switch input. The transponder configuration uses the "Squat Switch" setting to determine if you are on the ground or off the ground.
Click to expand...

That's the beauty of the Garmin system, you don't need either one, mine doesn't use either. Instead air ground is determined by software.
 
murphey said:
I just finished the THIRD attempt at the validation flight. Got this in the email:

"Your Performance Report request for Tail Number N2127R on 7/09/2017 failed to generate a result."

Swell. Just swell. I sent off a comment to the ADSBRebateHelp line pointing out that I've already spent $400 getting the airplane to/from the avionics shop and another $200 on the three failed validation flights and I'm fed up.

I turned it from standby to alt before I took off. It's night time and the buttons are NOT lighted! I had to turn on the ceiling light to make the changes, change the code (Denver center is very accomodating at 10 pm at night, 'specially when FTG is 5 nm from DIA)

So is Garmin going to get the fix out to everyone before the rebate deadline? And how is it going to be installed? By magic? I'm not going to fly 4 hours RT to the shop for the software update.

Just got the automated response from my request about the failed attempt:
"Thank you for contacting us. Please allow 3-5 business days for us to reply to your request."

grump grump grump grump grump.
Click to expand...

Cant the shop send you the installation manual? The backlighting on the buttons should be easy fix assuming you don't care if they are wired to a dimmer knob and would accept them be dimmed by the photo cell in the radio.
 
bnt83 said:
Cant the shop send you the installation manual? The backlighting on the buttons should be easy fix assuming you don't care if they are wired to a dimmer knob and would accept them be dimmed by the photo cell in the radio.
Click to expand...
I think I have the install manual, will dig out details.
 
Just got a response back from the ADSB team...Turns out date must be UTC, and I entered local.

"I suspect that our system failed to find your Performance Report because we store data according to GMT or Zulu time. Your flight on the evening of 7/9 was conducted on 7/10 Zulu. Your flight was flagged for air on ground problems but manual review of the flight indicates your avionics is working properly. We have cleared your reservation so you can proceed to the rebate claim."

Good thing, too. The cherokee went in for annual this morning, and not going to be another chance for at least a week.
 
murphey said:
Just got a response back from the ADSB team...Turns out date must be UTC, and I entered local.

"I suspect that our system failed to find your Performance Report because we store data according to GMT or Zulu time. Your flight on the evening of 7/9 was conducted on 7/10 Zulu. Your flight was flagged for air on ground problems but manual review of the flight indicates your avionics is working properly. We have cleared your reservation so you can proceed to the rebate claim."

Good thing, too. The cherokee went in for annual this morning, and not going to be another chance for at least a week.
Click to expand...

Good deal! Did you get the back lighting figured out?
 
bnt83 said:
Good deal! Did you get the back lighting figured out?
Click to expand...
Back lighting....I think so. But the cherokee is in annual and I won't get out to the airport until later this week. There's instructions in the user manual..will see if it's the solution.
 
Latest update - when the shop installed the 335, they left most settings in default mode. That included the backlight, hence last Sunday night, I couldn't see anything other than the 1200 panel display. Every time Denver center/approach gave me a new squawk code, I had to either turn on the cabin light or find the flashlight. Got the Pilot manual out today at the shop....amazing! The documentation is actually correct and I was able to get the backlight to work!

Of course the altitude shows 5200 when I know the ground is 5500 +/- 50 ft or so.
 
Transponder displays unccorrected pressure altitude reference to 29.92. Lotta pilots think it should match field elevation or altimeter, it will be close, when the altimeter setting is 29.92...
 
Walboy said:
I have a friend who recently installed a GTX345 for his ADS-B in/out solution. As is required, a test has to be submitted to qualify for the FAA rebate. The only thing that fails is the (Air on Ground) parameter below during an airborne test. This failure stands between my friend and his rebate. The avionics shop says Garmin says it's no big deal.

Any ideas on what could cause this? I have seen the report and everything else passes. The test result is from the Airbone 1090 analysis.

View attachment 48357
Click to expand...
This problem still exists in July 2017. I have made 2 40 min flight in class B airspace with my GTX335 and am still getting air on ground failures. Garmin is studying the problem but one would think it would have been resolved by now. I am sure that I am not the only one. !
 
GeorgeC said:
From the March/April 2017 FAA Safety Briefing:
Click to expand...
Well, A year later, I dont think this problem is resolved... I just received a REGISTERED letter from the FAA regarding an operational failure in the Air on Ground mode, for a flight made just before putting the airplane down for engine overhaul. Like many others, I passed the FAA rebate test (on the third try) by leaving the transponder in standby until start of take off roll, and same after landing... The monitored flight for which I received the FAA warning letter originated at KSNA (John Wayne) where transponders are used to monitor ground movements. Studying the FAA performance guidelines is appears really possible that the FAA has the right to cancel ADS-B services for aircraft that exhibit repeated operational failures. Garmin had advised that there were no tech adjustable settings that could modify inputs to the algorithm that determines the air/ground mode.. I believe that ground speed and rate of climb are two of the inputs. If Garmin does not, or has not, resolved this issue, I have the option of wiring my aircraft weight on wheels switch into the system and bypassing the Garmin algorithm... Anybody have any later info? I have not contacted Garmin since having the original problem after installation.
 
Just as a data point, we’ve had zero air/ground errors in our installation. Not during testing and not since the rebate.

How fast do you taxi? ;)
 
I have installed Garmin GDL82s and have noticed the same thing, usually occurs while obtaining a 3D fix. Upon obtaining then it changed to ground. Also recommended checking stall speed setting.
 
You must log in or register to reply here.
Back
Top