Tail Number Specification

Some commercial operators who do not have an airline “name” or “handle” file “tango” in front of the “N” number; such as “TNxxxx” instead of “Nxxxx”

I’m not certain if FLIGHTAWARE ignores anything to the left of the “N” on a tail number or not. My flights last evening were filed as “TNxxxx” but show here as “Nxxxx”; however, a search for previous flights does show “TNxxxx”.

Could someone clarify the handling of prefixed “N” numbers ?

Thanks - Greg

Hi, Greg, and welcome to FlightAware.

We don’t ignore anything, and we have tracked many air taxi (TNxxx) flights (although there’s an outstanding bug that makes them claim to be registered in Congo :blush: ). A controller may have erroneously stripped the T prefix off of your flight ident when accepting/activating your flight plan, and we received it T-less.

Lifeguard flights have a similar format, with an L prefixed to the N number.

I can understand a FSS person stripping the “T”, but most of the plans I file are via DTC on the 'net. When I review my plans there, the “TN” shows up. Plans opened are acknowledged as “TN” by clearance delivery, and enroute controllers call out with the “TN”.

I guess the “real” question is: If I put in “7235F” as a tail number to search, does your system include “*7235F” or is it specific to what I entered (i.e. N7235F or TN7235F) ?

Thanks - Greg

FlightAware will only display flights for the exact flight ident you enter. That being said, we automatically prepend an N to flight idents that look like N numbers missing the N (like 7235F).

We’re looking into this issue. Do all of your IFR flights from the last couple months appear in the activity history for N7235F? Can you estimate how many, if any, are missing? Possibly even give us the details (airports, dates, approximate times) for any missing flights.

Last night (11/30) I filed TN77RE from 3SQ → SDF and SDF → 3SQ. I was recognized as “TN77RE” on both trips; clearance, tower, departure, enroute, etc.

If you look at airport 3SQ activity it shows tail # N77RE.

So, I’m not sure what who’s removing the “T” but for our purposes what you are reporting works great since not everyone is going to file a “T” in front.

In that case, FlightAware is removing the “T” although we’re working on some more consistency in that procedure. Glad to hear it worked out.

Prefixes like this shouldn’t be removed in my opinion. The callsign should be identical to whatever it says on the flight plan. Same feelings for this idea of removing leading zero’s too.

Eg. Air France’s flight 004 is exactly that, not AFR4. Same applies for the ‘N’ prefix on reg’s that start with a digit, eg. N5NBHY. If you keep removing the prefixes you’re going to be alienating yourselves in the flight tracker traffic as all the others leave the callsign exactly how it shows on the flight plan and if people can’t find the flight they’re looking for on here but can elsewhere, they’re going to go elsewhere aren’t they :laughing: .

I agree with the above as well – providing the user can wildcard search the tail number. Consider a 135 operator who doesn’t have a “name” and some pilots are filing as “N77RE” and some “TN77RE”. This may seem like a minor inconvenience to some, but consider the fact that one has to remember to check both tail numbers, and, consider a fleet of many planes.
There is no regulatory requirement (to my knowledge) that a 135 flight be prefixed as “TN” thus you will never get all the pilots to do it.

So while I agree that tail numbers should not be manipulated, we need a way of wild-card searching to get both flavors.

  • Greg

Removing the prefix isn’t for the operator who knows what they filed as, but rather the user who doesn’t (significant other of an operator or passenger, spotter with a camera, FBO employee, etc). Also, by removing the prefix it’s easier to make all fights by the same tail number appear on the same page (the issue Greg refers to). Sometime soon we’ll add a notice that the TN flights were air taxi flights, just like we do for lifeguard flights.

We feel removing leading zeros is a good practice, since airlines can be inconsistent with how they file and the vast majority of passengers won’t know about them. As with the removing the Ts and Ls, we’re making it easier for Joe Average to track flights. I think the operator will be able to figure it out most of the time.
Adding an N to the flight numbers that start with a number is a bug we need to fix.

This is actually not true; regularly, aircraft file under their tail number and the FAA sends an update modifying the aircraft’s identifier to include a lifeguard indication.

Flight numbers are integer values and any preceding zeros are likely computer limitations requiring a minimum number of digits in an identifier and they do not change the number or increase the number of significant figures. ATC refers to AFR004 as “air france four” and COA001 as “continental one,” with no preceding zeros.

Additionally, anyone entering COA001 (for example) is automatically redirected to COA1, so people can find the aircraft they’re looking for. Aditionally, the FlightAware forms specifically ask for the tail number of an aircraft operating without a flight identifier, not for how the flight was filed.

Sorry but you’re wrong. ATC refers to the aircraft as per whatever was filed and if AFR004 was filed as AFR004 then that is what it MUST use as its identity on the airwaves at all times, in line with ATC procedures.

I have heard on countless occasions an aircraft call up as say “Air France 4” (example) only for ATC to ask them if they are Air France 4 or Air France 004 and what was originally filed. Often the flight will reply along the lines of “Air France 4… Air France 004… same thing…” and then ATC get shirty and make it clear that if you originally filed as Air France 004 then that is what you must use to identify yourself.

I’ve just looked up N5NBHY and it is listed and also if you key in 5NBHY it comes up too, but changes to N5NBHY. N5NBHY is the correct callsign for it as flight ID’s starting with a digit are required to use a letter prefix to avoid confusion, hence the N prefix, although of course it’s Nigerian and not American.

However, 8PMAK automatically changes to N8PMAK which is not correct as the correct ID is X8PMAK. While the latter does not change, it isn’t listed either which is strange, as it is listed on FBOweb and Red1. :confused:

Rob k is right with this and the ATC issue:
VIR008 is said with the zeros as is AFR004
If a controller is knocking of those 00’s then sloppy technique!
COA4 would be spoken as such if no leading zeros put in/on the flight plan but its a fair point about joe-public not knowing a full and correct flight callsign and how that audience can track their flight.
Try some of the crazy alphanumerics we also have over here:
EZY8KK7, BAW49WY, DLH3PP and honestly, shirty ATC staff? :wink:

Re: TN flights. I understand that 91/135 operators CAN file as Taxi. I can’t get anyone to tell me why they DO.

It seems that fractional operators frequently use ABC123 while flying within the continental US, but then file TN when they go to the Caribbean or Hawaii.

I pored through the NOTAM’s last year and could never find a reason why anyone WOULD/not file TN, only that they COULD.

Does anyone have information regarding: 1. Why I WOULD file TN? 2. Why I would NOT file TN? 3. If I am 91/135 in the lower 48 I would file ABC123, but when I file to Hawaii or Caribbean (or even Mexico, Canada) I change my filing to TN?

Thanks in advance.

TN = Congo. This is not a glitch, TN- is the prefix for aircraft registered in Congo Brazzaville.
It has been quite a while since I flew for a 135 operator but it was a bit controversial then too, I guess somebody at the FAA needs to sit down and figure out “why are we doing it” and then work out these types of problems with using it.

Not a fix, but a work around try the following links:


by manually entering the address, it eliminates the search.

A “real” Congo airplane is going to have TN followed by 3 letters. A US operator will have at least one number in the registration. You could have your software check it that way.

Most charter operators have more than one pilot flying the same aircraft, if one uses the T and others don’t we don’t get a true picture of what the aircraft is doing.

I don’t like the idea of arbitrarily altering somebodys call sign, but it appears the T is already sort of arbitrary so this may be one way to eliminate the confusion.


The reason that operators file TN is because after the sept 11 attacks, only aircarriers were allowed to fly for a period of time. If you didn’t have the TN filed, then you couldn’t fly. Many people still file TN. There are some TFR’s that only allow aircarriers to fly through them.