Anomaly with DAL1634, 23 March 2009

I was tracking DAL1634 (KSLC-KBWI) last night since I had to pick up my wife. Right around 10:30, the fight status changed to Diverted to “KKBW”. At the same time, I got a text message to that effect on my cell phone, since I had set it up for diversions and arrival. Then, two minutes later, the flight showed as “arrived” at BWI with an arrival time of 10:26pm.

Given the location of the flight at the time (38.38, -80.00) I first assumed that “KKBW” should have been “KBKW” (Beckley, WV). But then when the flight stopped tracking and showed “arrived”, needless to say I got a bit nervous (anxiety compounded when I got to BWI and the flight was listed on the arrivals board with a cryptic gate number [OP1] that corresponds to nothing else at KBWI).

Here’s what’s strange–when you look at the track log, it shows a proper conclusion of the flight and landing at KBWI at 11:02pm. My wife walked past the TSA checkpoint around 11:20pm–but we didn’t pull out of the garage until almost 12:30 due to a cluster #%#! at baggage claim. But of course I was just happy she was safe and sound.

Any idea what’s going on here?

Just speculation on my part: When a plane arrives, ATC puts an arrival message in the system. I don’t know specifically how that’s done, but if it requires the controller to type in the arrival airport code (KBWI), then it looks like the controller mistakenly hit the K twice, and then “BW” part of “BWI” producing “KKBW”. When the system reached the four letters, it accepted the data. The system would then recognize the KKBW is not its intended destination of KBWI and send a diversion message to the system.

That makes sense. So the weird coincidence is that at the time this was erroneously entered in, they were roughly 40 miles east of KBKW, a logical diversion airport (6750’ runway).

We’ve seen the same part with flights (generally from Canada) to Teterboro getting “diverted” to KKTE. I assume it’s some system upsteam of us getting a 4 letter code when it expects a 3 letter code, so it chops off the last character, then we get KTE/KBW and prepend the K to make it a 4 letter code.

Yeah, just a coincidence that KBKW is similar to the mistaken KKBW. I don’t really think Beckley would be a very good diversion location. While the runway is long enough for a 737 to operate, it’s an uncontrolled field and the terminal there is not equipped for such large volume of pax. I don’t think the taxiways are wide enough for such a big plane - it’d have to stay on the runway. Charleston, Huntington or Roanoke would be a much better diversion fields.

You mean that when humans are involved mistakes can happen? :slight_smile:

Thanks for the replies.

Good point. I guess if you *really *needed to land for whatever reason, it would be better than nothing but you’re correct that the other airports make much more sense.

Controllers do not manually enter “arrival messages”.

They do something that triggers an arrival message sent to us.

The aircraft lands and the ARTS track drops. That’s it.

I’m sure that “computer-wise” an arrival message is sent. But a controller doesn’t “type” anything to do this.

Do you know why the arrival message is sometimes triggered at a handoff from center to approach or approach to tower?

(Advanced apologies…)

Costello: Well then who’s on first?

Abbott: Yes.

Costello: I mean the fellow’s name.

Abbott: Who.

Costello: The guy on first.

Abbott: Who.

Costello: The first baseman.

Abbott: Who.

Costello: The guy playing…

Abbott: Who is on first!

Costello: I’m asking YOU who’s on first.

Link to the rest…

Mr. Duell, I honestly don’t know all the vagaries of the ARTS system.

All I know its a vast mosaic rather than a seamless integrated system.

One part of the system may not communicate very well, if at all, with another part.

The controllers have learned ways to work around the various computer/automation issues.

What has always amazed me is that Flightaware works as well as it does.

Want to dig deep? Here is the keyboard entry manual for the ARTS system. These are just the keyboard entries for the system. Its called the NAS MD 638. ( I found it at stuckmic)

Its a 544 page word doc, so beware!!!