Echo Tango
Well Known Member
I've seen a lot of confusion on the board about flight following, or tracking a flight on flight aware, and why flight following is sometimes terminated or a new code is given to a pilot during a flight. I thought I would do a short write-up on how airspace works pertaining to VFR flights and their relationship with FSS and ATC.
There are two computers in the FAA, used by controllers. One is the NAS (national, also known as "the machine") and one is ARTS (local). Each center (all 21 of them) has its own NAS computer, called "Host" (the name isn't important and won't be mentioned again), and they all talk to each other across the country, which forms a national database of all IFR and participating VFR flights in the National Airspace System; this is why Flight Aware will show your flight almost every time when you talk to the Center, but only sometimes when you are talking to an approach control. Centers = in the NAS (machine), approach = maybe in there.
Approach Controls are very like centers in that they have their own computers (ARTS). These are local computers and they have very limited capabilities (by limited, i mean we put in all or part of your callsign and that's it). The reason for this is generally workload (or laziness
) related. Just as the Center computer communicates with other centers to form a national database, ARTS associates itself with one single computer (the Center whose airspace is over top of it) and one computer only. This means if the approach next door to mine is under Cleveland Center, and I'm underneath Chicago Center, I can't automatically "flash" your callsign to "hand you off" to the adjacent facility. At this point, your flight is either terminated an we instruct you to contact the adjacent facility, or we make a short phone call and you just hear a frequency change and are none the wiser.
So with ARTS, you're basically an "x" followed by three numbers. That's all we see. If controllers keep asking you "whats your destination today" on initial contact, you're probably in ARTS. If you were in "the machine" we would get a paper strip (most places) with your destination, type, and (rarely) route on it. You will generally also get the same code "subset," as well, ie 02xx or 45xx. if you get one of these that you recognize, you're in ARTS. NAS codes are random.
Notice we haven't mentioned Flight Service yet. The simple reason is, we don't talk to them much. They protect you by looking at your enroute time and whether or not you call them to tell them you're still alive. An important side note here is that it's still a good idea to file a VFR flight plan even if you're talking to ATC. For one, we don't put in your Search and Rescue info, and even if you give it to us, we really have no way (or time) to relay that to anyone. Secondly, we might terminate you 15 (or more) miles from your destination, and if you don't make it there, nobody will be waiting for your call.
In summary:
1) If you're talking to a Center, you'll probably get flight following the whole way and your family can watch you on Flight Aware (though unfortunately it's not a real return, just a general "estimation" of where you are. If you burst into flames, flight aware will still show you happily flying your course).
2) If you're talking to Approach, you can get put into the machine if you ask (realize that it's a bit of a pain but most will do it).
3) If you REALLY want to be in the machine (and i dont recommend making a habit of it, because it's a bit of an abuse of the system) you can file IFR and just tell the controller to amend you to VFR when you call clearance/ground. Usually, we'll just amend your altitude and keep you in the system for flight following the whole way (we'll also have your whole intended route, instead of KXXX direct to your destination). I would still call FSS (after departure) as well and tell them that you're VFR and open/close as normal.
Clear as mud?
There are two computers in the FAA, used by controllers. One is the NAS (national, also known as "the machine") and one is ARTS (local). Each center (all 21 of them) has its own NAS computer, called "Host" (the name isn't important and won't be mentioned again), and they all talk to each other across the country, which forms a national database of all IFR and participating VFR flights in the National Airspace System; this is why Flight Aware will show your flight almost every time when you talk to the Center, but only sometimes when you are talking to an approach control. Centers = in the NAS (machine), approach = maybe in there.
Approach Controls are very like centers in that they have their own computers (ARTS). These are local computers and they have very limited capabilities (by limited, i mean we put in all or part of your callsign and that's it). The reason for this is generally workload (or laziness
) related. Just as the Center computer communicates with other centers to form a national database, ARTS associates itself with one single computer (the Center whose airspace is over top of it) and one computer only. This means if the approach next door to mine is under Cleveland Center, and I'm underneath Chicago Center, I can't automatically "flash" your callsign to "hand you off" to the adjacent facility. At this point, your flight is either terminated an we instruct you to contact the adjacent facility, or we make a short phone call and you just hear a frequency change and are none the wiser.So with ARTS, you're basically an "x" followed by three numbers. That's all we see. If controllers keep asking you "whats your destination today" on initial contact, you're probably in ARTS. If you were in "the machine" we would get a paper strip (most places) with your destination, type, and (rarely) route on it. You will generally also get the same code "subset," as well, ie 02xx or 45xx. if you get one of these that you recognize, you're in ARTS. NAS codes are random.
Notice we haven't mentioned Flight Service yet. The simple reason is, we don't talk to them much. They protect you by looking at your enroute time and whether or not you call them to tell them you're still alive. An important side note here is that it's still a good idea to file a VFR flight plan even if you're talking to ATC. For one, we don't put in your Search and Rescue info, and even if you give it to us, we really have no way (or time) to relay that to anyone. Secondly, we might terminate you 15 (or more) miles from your destination, and if you don't make it there, nobody will be waiting for your call.
In summary:
1) If you're talking to a Center, you'll probably get flight following the whole way and your family can watch you on Flight Aware (though unfortunately it's not a real return, just a general "estimation" of where you are. If you burst into flames, flight aware will still show you happily flying your course).
2) If you're talking to Approach, you can get put into the machine if you ask (realize that it's a bit of a pain but most will do it).
3) If you REALLY want to be in the machine (and i dont recommend making a habit of it, because it's a bit of an abuse of the system) you can file IFR and just tell the controller to amend you to VFR when you call clearance/ground.
Usually, we'll just amend your altitude and keep you in the system for flight following the whole way (we'll also have your whole intended route, instead of KXXX direct to your destination). I would still call FSS (after departure) as well and tell them that you're VFR and open/close as normal. Clear as mud?
Last edited:
