Live Flight Tracking

I have encountered several US-registered planes (tail numbers starting with N) which do not appear to be in the FlightAware or FAA registry. All of these planes have been flying for several years and some of these planes fly frequently. Here are some examples:

N340GZ
N993QS
N556MP
N211HV

I first through this was due to the planes being on the blocked planes list, but there is owner infos for the couple of blocked planes I checked:
- Bill Gates: http://flightaware.com/live/flight/N887WM
- Jerry Jones: http://flightaware.com/live/flight/N1DC
- Paul Allen: http://flightaware.com/live/flight/N902AF

How are these planes not listed in the FAA registry? Sorry if this is an obvious, but I cannot figure out how this is possible.

None of those registrations have logged an IFR flight in the US in years. Where are they flying?

Mark oops yes you are right. Here is another which I knew flew IFR in at least 2009 and I believe is currently flying (it is on the blocked list):
N802DR

More generally am I correct in thinking that US-registered planes with unknown owners are a temporary phenomenon (say due to change in ownership or reassignment of tail number) which would be resolved in a the next update or two of the FAA registry?

Thanks again for your help!

There was an aircraft registered N802DR in 2009. It now has a new registration.

Unknown owners are mostly due to changes in registration.

Thanks again for the infos Mark!

N211HV was a King Air 200 re-registered N102FG in 2005. Not a current registration.
N340GZ no idea - no a current registration.
N556MP was a Piper PA-46 registration cancelled in 2004. Not a current registration.
N993QS currently a reserved tail number.

All four registrations you have listed are not valid registrations, the database is updated daily, all four are not in the current database, and even if re-registered recently - would still be there.

As for N993QS that is a reserved tail number - so someone (James Morris of Omaha NB) has payed a fee to reserve this tail number.

It is possible they are old expired and no longer valid tail numbers.

If you encounter any of the above tail numbers - take a photo - you can also contact FAA or local tower to inquire.

Hi bizjets:

Sorry I had not checked on this thread in a bit.

Thanks for the infos very helpful! Can I ask how you know about the old registrations? The FAA takes their old databases down with each update.