Location: Slaving away in front of multiple CRTs, somewhere in the USA
Posts: 125
In a discussion at http://www.airliners.net/discussions....main/2601978/ it was suggested that the captain wanted an aircraft change due to a faulty IRU but was overruled. One of the posters has an airway map, and another said a Lion Air flight was in communication with the "lost" flight...
makes for a good argument to carry a handheld GPS and Transciever in your navbag when operating in remote parts. You might spend a whole career never having to resort using them but I never travel without them.
Specifically forbidden in our flight ops manual. But a good idea nonetheless...."
Why would the company forbid a handheld GPS? What is the thought process behind the ban?
Anyhow; I am reasonably certain that if you were to get on the PA and ask: " Anyone got a GPS and "Streets and Trips" or "Garmin Mapsource" in their laptop? You'll get a good show of hands!
Anyone else noticed how many pointless, thoughtless rules are dreamt up by incometeant half-wits who sit at desks trying desperately to justify their pointless existence ?
"Forbidden to carry hand-held GPS' " Why ????
Because it might interfere with the Nav equipment....well it can hardlyinterfere if it's switched off and if it's switched on it's probably because the precious nav equipment has failed...
It appears that a hand-held GPS doesn't receive signals through the flight deck window's heating elements. A passenger window's OK although it's rare that there are 4 satellites in the small cone of reception.
Carnt get mine to work on the flight deck of a B757. Been told its the heated windows.
My trusty old GPS100 (the very first Garmin/Pronav) worked just fine out of our good old Caravelle, mounted with velcro on the dashboard and later installed just below the overhead.
I had a Pilot 3 with me once on a jump seat ride, it would not work through the windshield but worked just fine when held next to one of the rear side windows. Might be a tad uncomfortable but a sight better than landing in the middle of nowhere. And no, we did not experience any problems with nav equipment whatsoever (A330-200). Also, they definitly work through the pax windows, but it might be a tad embarrassing...
Portable coms however have not much of a chance out of an airliner cockpit. We tried...
Was this at night? If it was daylight, then I'm puzzled. If you know you're over Java (and you'd have to be very very lost to not know at least that much*) just head straight north and pretty soon you'll reach the coast (Java is long and skinny). Then turn left, and pretty soon you'll either reach Jakarta or run out of island (there's very little of Java that's west of Jakarta), in which case a 180 will take you to Jakarta. Even at night this should be doable, as coastlines should show up pretty well. The ony way it wouldn't work is in case of complete overcast; there's some pretty tall mountains around, so you probably don't want to let down blind if you don't know where you are.
*: if you're sufficiently lost that you could conceivably be over Sumatra (not very far from Java), the same trick still works -- Sumatra is oriented NW-SE, so the coastline has an entirely different orientation, and if you start near the south coast, it could take you very long to reach the north coast; either way a compass and watch should be enough to establish pretty quickly whether you're over Sumatra or Java.
As regards to GPS antenna, a version can be bought which still receives signals through heating elements in A/C windshield. They have been around for years and I believe they have a "boost" current from the portable GPS it self.
I started using a portable GPS in A/C pre 1990 and before they were "banned." Yes it did interfere with the nav equipment in a way, as it was far far Superior than Omega or INS (litton 52's) The portable GPS was and still is mandatory standby equipment for me, pre and post ban.
As for the crew apparently getting lost due total nav failure. What about the standby compass?? That is just about the only instrument in the A/C that can be rely ed upon to give correct readings when all else fails. What would have been wrong with steering flight plan headings, as was pointed out in an earlier post, or is it the case that going back to basics are not taught anymore.
Last edited by doubleu-anker : 13th February 2006 at 21:47.
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