GPS not working on commercial flights - implications

Hi everyone,

I recently took a Southwest Airlines flight from one coast of the U.S. to the other. The airline (and plane) didn't have built-in displays, nor could I use its wifi, because I hadn't installed the Southwest app, before taking off (I forgot my headset, so I didn't bother).

I was surprised to find that I couldn't use GPS at all. If I tried Google Maps, it thought I was still at the airport we left two hours before.

Yes, I know about the Faraday effect. But it was still sad to think that here we are, maybe 7 miles up where GPS should be even more effective ... but, No.

But is it really as simple as a Faraday cancellation of GPS signals? Or is there something more going on, such as that my phone could get GPS signals, but needed some sort of network/cell connect in order to function properly?

I had airplane mode on, and wifi off (it was useless without pre-installing the Southwest app anyway). If it matters, I have an Android Pixel 1 XL, OS fully updated, not rooted.

So this is a general question about how exactly does GPS work. Does a smartphone truly have stand-alone GPS that could have worked fine if not for the metal skin of the 737-800? Or is there more to the story?

Thanks if you can help!

Try holding it up to the window. You need 3 satellites to get a 2d location and they are distributed all over the sky. The more sky you can see, the more satellites that can see you.

GPS is controlled by the US military and they can do whatever they want at any time, switch it off, degrade its accuracy or give bogus locations. Perhaps you strayed too close to a training area.

Did the seatbelt light come on, the captain gave a warning about turbulence and the drinks trolley suddenly disappear? No need to worry, those are just a precautionary steps in case the pilot needed to take evasive action.

GPS signals are very weak.

Cannot say I am surprised a GPS receiver cannot pick up the signals inside a screened tube with a few holes in it.

GPS satellites are 20,000km out in orbit, so 7 miles closer aint going to make much difference.

Perhaps dangle the GPS out the window ?

Hi, I use GPS all the time on commercial flights. Need to have receiver very near the window, Helps to have the GPS "found" on he ground before takeoff.

I use a Garmin GPSMAP78 but GPS discussion forums have lots of different ones used.

To make it REALLY nice, get an external antenna and cable that works with a GPS and tuck the antenna up under the pull-down shade. I have a neat recorded track that shows me 2 degrees from the North Pole on my way to China :-)

On a trip, get a good large road map for the area you will travel and figure out the cities and many different areas you go over. A road atlas is good and not too large. And it will have Lat-Long markings. I have done this with a child on a long USA flight, with good daytime visibility. They loved it.