RE: Questions for pilots familar with TACAN

From: Ted Molczan (
Date: Sat Dec 28 2013 - 13:27:34 UTC

  • Next message: Kevin Fetter: "soyuz launched today"

    My description of the motion of the fireball depicted in the painting made by the witness of case 10695 was mistaken. It
    was of course, from right to left. I edited the web-archived copy accordingly.
    Also, I forgot to mention a possibly unusual feature of the CIRVIS report of case 10696, on pp.6-7, which seems to
    suggest that the fireball was detected by an airborne radar. Pg.6, under 3) Object Heading, mentions "Airborne radar
    report of 110 degrees". Pg.7, under J), reports "Left one continuous line across airborne radar scope."
    The ion trail from the re-entry and break-up of Space Shuttle Columbia left a persistent streak on a ground-based
    weather radar, recorded in this time-lapse video:
    Regarding the case at hand, the trajectory of the 66046B debris was on a heading of about 112 deg, very close to the 110
    deg of the airborne radar report. (In its MERINT report, USNS Longview also reported a bearing of 110 deg.)
    How common was airborne radar on commercial aircraft of the day? Would it have been likely to detected the ion trail of
    a large fireball, whether meteoritic or satellite re-entry?
    The only aircraft identified in the case, was Qantas flight 531, but another sighting is attributed to "L/Col Duncan,
    154th FTR GP", which suggests that observations may also have been made from a military aircraft in the area.
    Final comment and question: The re-entry trajectory would only have been directly observable to the eye on a 112 deg
    heading by an observer in the plane of the orbit, i.e. for whom it passed directly overhead. The 110 deg reported by the
    airborne radar seems to suggest that it was located close to the orbital plane, i.e. had a high elevation pass. Would it
    be safe to assume, therefore, that the radar must have been near the orbital plane, or could the true heading still have
    been determined from a sighting far from the orbital plane?
    How much weight should I give the radar report, considering it is not very detailed?
    Discussion welcome on-list, as well as off-list.
    Ted Molczan
    Seesat-l mailing list

    This archive was generated by hypermail 2b29 : Sat Dec 28 2013 - 13:28:25 UTC