Posts: 438
Joined: Mon May 24, 1999 11:24 am


Mon Jul 05, 1999 11:49 am

I know that GPS is used in Europe, and not extensively in the US. If the US does go a GPS based tracking system sometime in the future, how much equipment would be required for planes to be retrofited and for any infrastructure required?


Posts: 2
Joined: Fri Jul 27, 2007 10:50 pm


Mon Jul 05, 1999 4:49 pm

I have never heard of a GPS tracking system. Could you describe how the system works? Since the aircraft only have receivers I can't see how ATC could track an aircraft.
Posts: 41
Joined: Tue Jun 21, 2005 4:32 am

Global Positioning System

Mon Jul 05, 1999 6:18 pm

I am not engineer or anything, I just have a GPS-receiver. I don't think it's too complicated to fit a gps into an aircraft, in fact, I saw a helicopter with nearly same gps receiver that I have, it just had a different power supply. But in a plane, I don't know about that. I'd suppose it's quite straightforward procedure, just fit receiver and some wires and it should work.

Trijet, what do you mean track the plane with gps? Don't ATC use radar anymore?
GPS should never be used as only navigation instrument in a plane, VORs NDBs amd others should be used instead of them. However, with GPS you don't have to have any beacons, you can go where you want, if you know the coordinates of that place, or if it is programmed in the receiver.

If you have any further questions about gps, go ahead.

take care
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Joined: Mon Jul 05, 1999 8:40 pm


Mon Jul 05, 1999 9:05 pm

Very simple really, a GPS flight managment system in the cockpit and antenna's is the basics of it. Our Dash-8 200 models have a dual GPS FMS on board. The FMS' are loaded monthly with updated navigational information. Of course VOR and NDB are there as well, ATC track with transponder-totally independent of the GPS.
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Joined: Mon May 24, 1999 1:12 am


Mon Jul 05, 1999 9:15 pm

Like Dash8Tech says, it's very simple. The Piper Aztecs I fly are fitted with the system, it's just a simple antennae, let the system orientate itself before departure (but it's not like INS, you don't have to sit there for ages stationery, it's a few seconds), then program all the waypoints which are beacons (by entering the three letter ICAO codes) which are in it's memory, and there's a 'moving map' screen that clips onto the yoke and visually draws the airways, beacons, suitable fields en route etc. It takes about five minutes to enter all the waypoints. We get a small cartridge once a month or so and that has all the updated info. After departure you couple the autopilot to the nav mode and the GPS navigates the plane from beacon to beacon, and we retune the nav radios as we go, to crosscheck the accuracy of the system, which so far has been flawless.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
David L
Posts: 8547
Joined: Tue May 18, 1999 2:26 am


Tue Jul 06, 1999 4:35 am

I'm curious to know about the vertical accuracy. In my living room my handheld GPS usually has my horizontal position within 20 or 30 metres but the height sometimes varies by a couple of hundred feet.

Don't get me wrong, I don't use it for getting around the flat. Well, not any more - I've been living in it for over 4 years now. It was just an experiment.
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Joined: Mon May 24, 1999 1:12 am


Tue Jul 06, 1999 7:02 am

Not sure about it's usefulness to determine elevation. I often program it but I'm in the right hand seat and it's mainly operated in flight by the PIC. But I do operate it too and have never seen a readout on any of the pages (multi-function screen) that refers to elevation. It may do internally do it though, because I understand that sometimes it needs to correct - or can be slightly out - if the receiver is picking up the GPS signals at an oblique angle. Not sure though.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
Philly Phlyer
Posts: 356
Joined: Sun May 23, 1999 12:05 pm

GPS Already In Use In US

Tue Jul 06, 1999 8:48 am

GPS already is in use in the US on some commercial flights. As the carriers take delivery of their newer airplanes, these are equipped with GPS systems.

I fly US Airways alot and was on their first GPS guided flight (in May on an A319 from TPA to PHL). I also know Continental is using GPS on flights with some of their new planes.

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