Meaning of SC1, SC6, ZZ3 origin/destination codes ?


I see these designations (in paren) on some flight tracks where one would normally see origin/destination codes. When I click on that I get this error message:

Unknown or Invalid Airport Code
Hint #1: Airport code must be a 3 or 4 digit ICAO (e.g., AUS/KAUS) or FAA (e.g., 3R9 or CA35) code.

Hint #2: IATA codes are not currently supported (i.e., Tokyo/Narita’s ICAO code is RJAA, not NRT or KNRT).

What do these designations mean ? I don’t see any relevance when I look up IATA codes.


Tracking my son’s Mooney N1171P


They appear to be codes used by controllers to indicate origin for VFR or popup IFR flights instead of an airport or a VOR. From what I’ve seen it appears SC1-7 and ZZ1-6 are in southern California.


I’ve also seen VG4, VG2, etc…they appear to come from Vegas.

Also, for some reason, controllers like to add the ‘K’ in front of a VOR. Like KVTU, KBZA, KEHF, etc. Makes it look like an airport at first, until you click on it and there’s no airport.


Tx Guys - makes sense. My son flies out of Santa Monica and is not yet IFR-qualified.



Tough airport to fly to/from. It is just a few miles from the edge of the LAX class B airspace and surrounded by other good sized airports as well. If he can fly there, just about anywhere else will be easier.


Yes, that’s what sonnyboy was told - learn to fly in Socal and the rest is easy. He barely has 100 hours so far but is pretty comfortable through LAX airspace and into most surrounding airports - there is some quicky direct route through that Class B for general aviation that controllers send him through - forget what its called.

He has no trouble flying up to me in the SF Bay Area though SFO/OAK airspace (although the crosswind at Gnoss in Marin County gave him some initial trouble) and will be flying to OAK this weekend if the weather holds.



I think you are probably referring to the LA Special Flight Rules Area (fondly known as the SFRA), which requires no communication with ATC and no LAX class B clearance. There are also 4 other special routes through the class B which require you to get class B clearance and maintain ATC contact. If he flies the SFRA into Santa Monica, he may just make the runway if he completely cuts the power and puts full flaps and gear down immediately at the edge of the route. It takes your A game to do that one.

When he gets his Instrument Rating, he should try the Tower enroute clearance from SMO down to San Diego. It starts something like "Fly runway heading until intercepting the LAX 315 degree radial, then turn right and track the 315 radial, then radar vectors direct SMO VOR, then SMO 124 degree radial until intercepting V123, track V123 until intercepting V456 etc. all within the first few minutes of departing into the Santa Monica clouds. It can’t be programmed into a GPS, so it has to be manually navigated.

Gnoss was sighted incorrectly when it was built (they just used approximately the same runway heading as Petaluma airport up the road a few miles) and it has almost perfect 90 degree cross winds in the teens gusting into the 20’s all summer. If he can handle that safely, he should be able to do almost any crosswind that his plane can handle. I’ll send you a PM with a trick one of the old-timers there taught me.


Can’t resist. He gets in the plane, files above, gets all nice and cozy mentally ready for the above gyrations, and then what happens?

Cleared as filed or N#### amendment to your clearance, ready to copy?

The above sure makes me appreciate the land of GPS direct! :stuck_out_tongue:


Actually, you can file GPS direct to [pick your favorite SD airport], but when you get your clearance I am told that there is a 90% chance it will be the above for a piston aircraft. Here’s a brain teaser for you: how can you determine what to file and how can you determine what you are likely to get? When I did it the first time, I asked at the SMO VOR for direct to VOR and got an explanation from ATC why I would not get anything other than that routing no matter how many times I asked.


Use the FlightAware IFR Route Analyzer!


You cheated and looked at the answer book. OK, anyone, what is the other half of the answer?


Nothing on the maps really jump out at me looking at flight planner maps.

Ran this through my flight planner to get a feel, and looks to me got some big rocks to the right and restricted airspace to the left around Ventura. Also NOTAMS on the SMO VOR makes me think that could be a factor???

VOR/DME UNUSBL 260-280 BYD 15 NM BLO 4000 FT; 280-290 BYD 20 NM BLO 4000 FT; 290-330 BYD 30 NM BLO 8000 FT; 330-360 BYD 30 NM BLO 6000 FT; 360-030 BYD 35 NM BLO 9000 FT.

Autorouting of the flight planner had me go from KSMO SADDE VTU KSBA KSBA which seemed reasonable based on the Nav maps.

Ran this also through AOPA flight planner, and that took me KSMO SMO SADDE V107 VTU V25 ZIQOR

Had it been me, would have filed the first one for the lesser fixes :slight_smile:

Of course, like you said what I file and what I get are two different beasts, thus me appreciating the land of GPS direct.


I had forgotten this one from training days as well. The answer is the Airport Facility Directory shows preferred routes. So the route you find there from SMO to MYF is
SCTM14 LIMBO V64 V363 V23 MZB PQ50

which means that you just file on your flight plan SoCal Tower Enroute M14 (SCTM14).

As Mark Duell also posted, you can also get that information by going to the FlghtAware IFR Route Analyzer and entering SMO for the departure airport and MYF for the arrival airport. For low altitude flights, it shows the routing as SCTM14 (SoCal Tower Enroute M14). You would still need to go to the A/FD to find what the routing for that is.

Mark: It would be a handy feature for FA to link those routing names to a page containing the routing waypoints (in this case:


AFD? You mean that drab green cover book that I never “open” due to me using a better AFD version (called flight guide). Didn’t those green books go by the wayside of pencils since the day of Internet? :stuck_out_tongue:

Thanks for that acute reminder, as to be honest, never would have looked in there! With all the flight planning automation in my two planners, you would think that the preferred routes would have come up as an “option” to select from based on airport selection, but neither flight planner did that.

I likey, I likey especially when one considers using Flight Aware as another tool in their tool kit for IFR flight planning.


I didn’t think of it either. I was at American Fliers at SMO dropping off a passenger and asked an instructor what they typically filed SMO - MYF and he was kind enough to remind me of one of the basic tools of the trade. I can’t remember the last time I looked at an A/FD.


Back to the original question, those are the sector designations. The flights in question most likely have requested an IFR approach or perhaps a full enroute clearance while in that sector rather than doing it on the ground before departure. SC1 most likely is socal approach sector 1, wherever that is.

We got preferred routes over here too, I fondly call them " you vill file this airway and only this airway, and you vill like it" routes.


Just as we were discussing this topic, our friendly airspace designers in SoCal changed the TEC routings. I found an online source for the A/FD that contains these new routings (page 358 of the document and page 368 of the pdf): NACO A/FD

Online A/FD is here:


So-Cal Tracon opened in 1994. They brought five tracons into one. Since they opened, they split off LAX arrivals from departures and took more center airspace. There are now six areas. Burbank-1, Lax-2, Ontario-3, Coast-4, San Diego-5, Lax/departures/VFR Class-B-6. Depending on who initiates your Center generated vfr flight plan, that area is the starting point for flight following as far as the computer is concerned. A direct line to projected from a common point in their area, to your desination.

You call So-Cal Approach (the old coast approach sector frequency) for flight following to Frenso from Orange Co. The controller will type: N12345 FAT BE36 105 (enter). The host computer will give the controller a code based on Seal Beach direct Fresno Air Terminal and 10500’. Once the center generated code is received, the point of departure will be SCT4.

Hope that helps.

P.S. The So-Cal Tec routes are about to be updated to “November”, so check your routes before you depart!!!


Ok here’s a new one. I noticed a Cessna coming here from LGWW. HUH?? Isn’t that Europe or something??
So I click on the map, and it appears to have originated around KLGB. Wonder where the LGWW came from.

HiChappells, where would SC7 be? I’ve seen that a few times as well.


I haven’t posted on here in a while, but I was a controller at SMO until January '08, so I can tell you about those questions . . .

. . . for guys coming out of the SFRA, I liked to have the traffic cross midfield and descend on the right downwind and advise when they were ready to turn base if I had traffic, or report turning base if I didn’t. None of the controllers there (at least that I am aware), would try to get a pilot to chop and drop unless the pilot said they could or wanted to do it, but to each his own, I guess.

. . . The TEC (and all IFR clearance) routes for P and M class aircraft (when SMO is 21 and LAX is west) is “Fly runway heading, at the LAX 310 radial, turn right heading 270, radar vectors to . . .” The most challenging one to read was Jets to San Diego . . . I’m sure it’s 5 times as hard to fly.

. . . Your airplanes are capable, but SoCal TRACON can’t take routes like that; the airspace is too congested. Out of Santa Monica, all the smaller guys going south or east get routed over SMO SMO125R V64 SLI. I think the SBA guys get SMO V107 SADDE V299 VTU VTU282R KWANG, but if you’re going further north, it’s direct VTU and then whatever you want, but they’re separating guys on TEC routes and other flight plans with altitudes.

At the tower, we didn’t have a choice, we had to give the full TEC route, but if you have the right SCT controller at the right time, it’s not unheard of to get direct MZB if they could work it out.