Almost 6000 of the current 38000 ADS-B equipped FAA registered aircraft so far, are NOT PERFORMING because of a simple mistake which has something to do with the Certificate of Registration !
According to an article by By Woodrow Bellamy III in Avionics magazine, the latest available data from FAA shows that 18 percent of all U.S. registered ADS-B equipped aircraft have non performing equipment (NPE).
You can read the article here: http://www.aviationtoday.com/2017/07/27/18-percent-ads-b-aircraft-npe/
The biggest problem is in General Aviation (GA) fleet because the transponders are not properly programmed (or pin-strapped correctly). There are large aircraft and airliners that also fall into same NPE category.
Think about the air traffic centers getting an ADS-B signal, but it excludes aircraft registration info, to recognize type or model. They need to know if the ADS-B signal is from a small Cessna or a large Airbus. If the aircraft Transponders are not sending the unique (specific to each aircraft) 24 bit ICAO code, incorrect code or just 000000 or FFFFFF HEX (16 based) codes, then your ADS-B is not performing.
Take a look at your FAA Certificate of Registration card, and locate the ICAO Aircraft Address Code. The code on FAA Form 8050-3 is in OCTAL (8 based), which needs to be converted to 24 digit BINARY (2 based) zeros and ones, and to be used for pin-strapping of the transponder rack or CDU programmable ATC-Transponders.
If you need to convert OCTAL or HEX (16 based) number to BINARY, you can google it, or send me a message with copy of your Registration Card and we will convert it for you.
The GA fleet is much error prone to this ICAO (or Mode-S) address code because as upon change of aircraft ownership, the new owner wants his/her own N number, and most often ignores the rewiring or reprogramming of the ATC box(es).
Now, there is an EASY WAY I found to TEST YOUR AIRCRAFT ATC TRANSPONDER ….. Yes, there is an App for that !
Install FlightRadar24 app (free version) or go to their website. Go to SETTINGS > VISIBILITY. Turn OFF AIRBORNE AIRCRAFT and turn ON GROUND VEHICLES. Find the location of where you thing your aircraft is on the app’s (or website) worldwide map. Make sure your aircraft is not inside a hangar or too close to buildings. Activate your aircraft’ Transponder and set it to 1200. After 30 sec or so, your aircraft should pop up on the map. You can select (or click on) your aircraft and read the Mode-S (same as ICAO address) HEX code being transmitted to the ATC system. FlightRadar24 will also link your N number to the Mode-S Code and show it. So if you read an N number different than what is displayed on the side of your aircraft fuselage, then you know what needs to be done. Do the same test for your 2nd (if installed) transponder. (This test in only to check Mode-S code. Not your ADS-B)
This lack of correlation between aircraft and its transponders is also a major Homeland Security concern. So for those of you aircraft traders, think about fixing this as soon as you buy an aircraft from an unfriendly or semi-friendly country before flying it into US airspace. Simply getting an Number and painting it on the fuselage is not enough. You may not be considered friendly when there is a hair-raising ID difference between what the incoming aircraft transponder says and pilot’s verbal N number ID on the radio!