FlightAware Discussions

Can anyone explain why ADSB is picking up this plane in FL when it is in fact in Arizona right now?

Not sure why ADSB would have a whole flight thousands of miles from where the plane physically is, especially given the plane was tracking fine a week ago at its current location: N4541F Flight Tracking and History - FlightAware. Does this happen often?

Hi,

That is fairly common, and can happen for a number of reasons.

Here is the actual aircraft:

The aircraft going from TLH to Miami was actually N4514F. The clue is that the flight you linked to was not an actual ads-b flight track, it was an FAA radar track. For whatever reason, when the actual N4514F aircraft was entered in to the FAA system incorrectly as N4541F. The real aircraft has an ads-b trail available. The false aircraft has an FAA radar track available. If you look closely at a replay, you can see both NE of TLH shortly after takeoff. The false aircraft did not go all the way to Miami, because the FAA error was likely noticed and the actual N-number then assigned to the radar track.

It is also fairly common to see two fairly close tracks for a real aircraft. One is the very accurate GPS position received directly from ads-b and the other is the less accurate position received from FAA radar sources. A similar thing happens when you see rebroadcast TIS-B and ADS-R traffic “trailing” real aircraft.

If you are curious, take a look at the “View track log” for the aircraft you posted. You will see that normally it has ads-b positions. On the 5 JAN flight you mentioned it was showing “Jacksonville Center” or FAA radar positions.

-Dan

Thank you for the explanation. It makes sense. It is my airplane but I did not think to check the actual data from the TLH track.

On another topic, we did not have any ADSB coverage in middle Nevada at all on Dec 28. Someone should really put a receiver or two up there!

Regards,
Karl

Karl,

Yes, that is definitely a big one-hour gap in the data. I am surprised the FAA radar coverage did not fill in part of the data, but of course there were the mountains. The flight path looks like a VFR track and I noticed a 1200 squawk on the FlightRadar 24 data, so that seems to confirm you were likely VFR. If you were on an IFR flight plan, it is possible that parts of those gaps might have been filled with FAA data. That’s just a guess.

Glad to see you avoided all that airspace on your left side on the way to south of Vegas! Good plan.

-Dan

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Yes the ceilings were about quite low that day, and visibility was enough to see a mile or three, so we were flying the valley floors at 500-1000 all the way through that high country, hugging one side to give ourselves room for a standard rate 180 if we went total IMC. I was hard on the topo lines on Foreflight with GPS and my friend was flying. Luckily we could see the ground and follow the little rivers up, over and down the low parts of the valleys as well as the slopes on either side. We were low enough in mountains that we could not raise Desert Center on the radio and had to climb up to 9000 or so to ask them if the restricted area south of the solar farm was hot, which was only about 2500 agl, then up to 11,500 to get over that training area, after which you can see us do the mother of all S turns to get down under the clouds again and continue south. If I dont fly any high country in those conditions ever again, it will be soon enough for me. The 430W and Foreflight did a good job keeping us away from all the no fly zones - that part was comparatively easy compared to getting over and through all those little mountain ranges, whose peaks were all in the clouds, both north and south of Winnemucca. It is blue sky day country or full IFR up there - no inbetween. I think it was cold enough that we could have gotten up on top without ice, but we didnt have O2.

Like radar, ADS-B is essentially line of sight (1090MHz ADS-B is in fact using the same frequency as regular SSR transponder responses) so it’s hard to maintain coverage close to terrain without a lot of receivers…

Thanks for this information. I guess I was surprised that we did not fly over even one ground station out there, but given where we were flying, it should not have been a surprise. There are some dead areas in NM and AZ also.