Contrary to popular belief, us pilots do know how to fly without GPS. I have never seen an IFR aircraft with a GPS that didn't also have a VOR receiver. Any VFR aircraft can be navigated using the Mk I eyeball.
IFR certified GPSes have integrity monitoring. So, if the signal gets jammed or there is another system failure, the approach should be aborted and the flight switched to another navigation means. This LORAN debate is all well and good, but most of the general aviation fleet does not have LORAN receivers. They haven't been manufactured in years. On Sun, Nov 15, 2009 at 8:33 PM, Didier Juges <did...@cox.net> wrote: > Not all GPSs are on airplanes, but those I am really worried about are. > > I don't care if the GPS receiver in my cell phone stops working in some > locations, it does not work everywhere to begin with (like in the house, I > can't use it to find the bathroom in the dark...), but I worry that the one > guiding a missile or a fighter plane might not work. I also worry that the > one abord a large passenger aircraft might not work. Most of those that are > stationary or move on the ground or on water, I am not too worried about. > > For instance, the local garbage pickup people use GPS to locate the houses > of customers who have unusual (large or unsafe, or possibly contaminating) > garbage to pickup. I have had a dead TV on the side of my house for 3 > weeks, > three times I called and 3 times they missed it because the GPS guided them > to my front door (my normal mailing address), but I live on a corner lot > and > the garbage pickup is on the side of the house, by the garage. If that > particular GPS receiver stopped working and forced the employees to look > around, it would not bother me (the TV ended up in the trash can. After 3 > times and 3 weeks, I assumed I had done a reasonable attempt at avoiding > putting too much lead in the garbage, and it had to go.) > > Didier > > > -----Original Message----- > > From: time-nuts-boun...@febo.com > > [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson > > Sent: Sunday, November 15, 2009 7:03 PM > > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] The Demise of LORAN (was Re: > > Reference oscillator accuracy) > > > > Francesco Ledda wrote: > > > Considering that the GPS antenna in aircrafts is mounted on top of > > > fuselage, and that its radiation pattern is upward, it seems that a > > > ground jammer will have an uphill battle. > > > > Not all GPS receivers is sitting on flying airplanes. Far from it. > > > > Cheers, > > Magnus > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, > > go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
