registration number


How can two different types of aircraft have the same registration number? This was recently shown on Flightaware.


They can’t. Please provide the registration that you think is duplicated.


What is the registration number?

No two aircraft can have the same registration number. There can be two aircraft with the same flight number, but that is only in very few situations in which there could be a flight (to give an example) going from Los Angeles to Houston and then connecting to New York, all on the same flight number. Even though they may have the same flight number, they can, and often are, two different airplanes. This is usually done that the LAX-IAH leg arrives and then an hour (or however long) later, the second aircraft departs on the IAH-JFK leg.

Sometimes though, if the LAX-IAH leg is delayed significantly, (anywhere from 2-4 hours late), to keep the schedule going smoothly, they’ll let the other aircraft (IAH-JFK) depart. If there is a significant gap between the two aircraft and they will not cross paths nor interfere with ATC, they’ll keep the same call sign and flight number. If they will do any of the above and/or be too close to each others arrival/departure times, they’ll add a letter to the call sign or give the flight a completely new flight number. The new flight number and/or addition of a letter to it involves a lot of paper work, so if there is room, they’ll just send it out with the same flight number.

To go back to the original question though, they can not have the same registration (a.k.a. tail number).


Sometimes a typo on the entry of flight plan for type of plane will cause discrepancies on Flight Aware under the same tail number.

BE23 may be transposed as BE32 and so on.


There is one possibiity that involves the air traffic controllers.

Let’s say you have N345 flying in California. In New York you have N12345 flying. It’s a pop-up IFR flight (it starts its IFR flight plan while already in flight - is that the right term?). The air traffic controller in New York may leave off the first two digits of the registration and enter it as N345. Thus, you have two aircraft that *appear *to have the same registration.


Yes you are correct in what the term “Pop-Up IFR” means, but if a controller ever did just put in the last 3 digits, there would be a world of hurt for that controller. They are required to enter all the digits from a registration number for a clearance. I’m sure it can and has happened, but it’s one of those possibilities to explain this, but shouldn’t even occur.


Usually a typo (N223AB instead of N233AB) by the controller or just the last three digits (N3AB instead of N223AB) were entered and they are the same as a valid registration.