Sunday, October 28, 2012

Strip Puzzler

I saw this strip yesterday, and happened to notice something interesting. Any guesses?

16 comments:

  1. something to do with flying LAX to New Orleans?

    ReplyDelete
  2. Since the flight is staying on J169 to TFD I don't think it was necessary for the intersection KOFFA to be named but it doesn't hurt. Is it necessary on the strip because of a sector handoff?

    ReplyDelete
    Replies
    1. Most likely; that sort of thing appears often.

      Delete
  3. NRP - National Route Program?

    ReplyDelete
  4. "TRM J169 Koffa J169 TFD" Why J169 twice?
    Why not "TRM J169 TFD"? Also, in previous strips you've shown, LATA (LAX tower) was displayed.

    While you are on the subject of strips, how is a transponder code selected/generated? Why is it that sometimes Center will ask us to change the code in flight. Thanks in advance, CV.

    B

    ReplyDelete
    Replies
    1. As PeterC suggested, that route segment most likely is for coordination purposes. Off the top of my head, I don't know where the boundary between Los Angeles and Albuquerque centers falls, but somewhere in that vicinity seems likely. The ARTCC computers do not have infinite memory for waypoints and fixes, so you're best filing a route that includes fixes that the computers do know.

      The LATA often appears on the strips I show here because they are duplicates that I requested, and when those print out the requesting position or terminal is printed on the strip so that the flight data controller can deliver them to the proper controller or position. For this one I just took the photo and then filed it with the other departure strips.

      The transponder code is generated either by the center computer or the Tracon computer, depending upon the filed route. Each facility has an assigned bank of codes that they can use, and there is some sort of system to prevent code duplication in adjacent facilities. However, if you traverse enough different facilities, you may well get to one in which the code you received at your departure point now conflicts with another flight that has been assigned the identical code. I remember seeing this regularly at my first facility (MLU _ Monroe, Louisiana), which is a tower-tracon located beneath the convergence of three centers (ZFW, ZHU, & ZME). A flight would enter one side of the airspace from one center, and have to change codes before it could be handed off to the (different) center on the other side of the airspace.

      Delete
  5. NRP is North American Route Program...MissTwa told me this is my homework... :)

    NRP? an aircraft is moved because of weather, traffic, or other tactical reasons......

    Hmmm...is that interesting? :)

    Looking forward to the REAL reason you found this interesting.

    ReplyDelete
    Replies
    1. NRP appears commonly on airline departures out of LAX; Not especially important for us as tower controllers - the main point is that we should not amend the filed route.

      Delete
  6. While I didn't intend for this to be especially sneaky, I guess I should have said that an interesting coincidence appears on this strip. There are some red herrings that have distracted you from what I saw. First commenter Caroline saw part of it . . .

    ReplyDelete
  7. The number nine appears often. I'm really stumped on this so here is what I see. Flight 504 adds up to nine. It departs at 9 PDT via HOLTZ9 to J169. That's pulling at straws but I now officially cry uncle.

    ReplyDelete
  8. 504 is the area code of New Orleans

    ReplyDelete
    Replies
    1. And we have a winner! Nice going Andrew!

      Delete
    2. Thanks!

      One question. What is the meaning to the number 3 below LAX in the middle of the slip? I imagine 83 was the gate #?

      Delete