No GPS receiver allowed on Virgin Atlantic?
Thread Starter
Joined: Nov 2014
Posts: 2
Likes: 0
From: UK
No GPS receiver allowed on Virgin Atlantic?
On a ATL-LHR flight the other day I noticed that the Safety on Board cards said:
"Global Positioning System (GPS) and intentionally transmitting devices e.g. radio pagers, satphones, radio transmitters [blah blah] must not be used at any time."
Now I can understand that most of the gadgets listed might cause interference and therefore shouldn't be used, but GPS? AFAIK a hand-held GPS device is passive with signals going from the satellite to the receiver only, therefore doesn't present any more risk of interference than a mobile or lap-top in flight mode, which are permitted.
Or do VA fly some magical route that they don't want anyone to know about?
"Global Positioning System (GPS) and intentionally transmitting devices e.g. radio pagers, satphones, radio transmitters [blah blah] must not be used at any time."
Now I can understand that most of the gadgets listed might cause interference and therefore shouldn't be used, but GPS? AFAIK a hand-held GPS device is passive with signals going from the satellite to the receiver only, therefore doesn't present any more risk of interference than a mobile or lap-top in flight mode, which are permitted.
Or do VA fly some magical route that they don't want anyone to know about?
Joined: Oct 2011
Posts: 703
Likes: 0
From: United Kingdom
They're not the only airline to specifically forbid their use, but with a moving map feature I've no idea why you would need to on VS.
Instead of specifically forbidding the use of GPS devices most airlines will simply not include them in their list of approved devices, and non approved devices are not to be used at any time and thus if GPS units are not on the list then they don't get used. They may be passive but they are still receiving a signal which is where the interference issue may come in to play.
It is the same on BA "Any device that transmits or receives communications but does not have a ‘flight safe’ mode, must be switched off for the duration of the flight" and neither easyJet or BA include GPS devices as an approved device.
It seems Vs is making it crystal clear that they are not allowed. That's my understanding anyway.
Instead of specifically forbidding the use of GPS devices most airlines will simply not include them in their list of approved devices, and non approved devices are not to be used at any time and thus if GPS units are not on the list then they don't get used. They may be passive but they are still receiving a signal which is where the interference issue may come in to play.
It is the same on BA "Any device that transmits or receives communications but does not have a ‘flight safe’ mode, must be switched off for the duration of the flight" and neither easyJet or BA include GPS devices as an approved device.
It seems Vs is making it crystal clear that they are not allowed. That's my understanding anyway.
Son of Slot
Super Senior Moderator
Super Senior Moderator
Joined: Feb 2013
Posts: 2,051
Likes: 615
From: London
snowyfish Welcome aboard the cabin of PPRuNe.
If you look through the http://www.pprune.org/passengers-slf...slf-forum.html so carefully prepared by my predecessor, you will see your question there..
Bear in mind that you have a legal obligation to follow the instructions of the airlines and their crew.
If you look through the http://www.pprune.org/passengers-slf...slf-forum.html so carefully prepared by my predecessor, you will see your question there..
Bear in mind that you have a legal obligation to follow the instructions of the airlines and their crew.
Joined: Feb 2000
Posts: 3,585
Likes: 0
From: UK
Please also remember that you may be contravening U.S. FAA regs and therefore breaking the law: Americans are twitchy about such things in the wake of 9/11 and one can well understand why. In short, if you choose to ignore the restriction, and are caught, you would be dealing with the FBI rather than the airline. That would probably not be a fun holiday experience.
Joined: Jun 2001
Posts: 4,369
Likes: 3
From: UK.
Arrrh, Snowy lad, tis forbidden to know the ship's position lest ye motley swabs do mutiny and seize her from her rightful cap'n to go a'piratin' 
Last edited by Basil; 15th November 2014 at 14:10. Reason: Sp - and no-one pointed it out! Tsk! :)
Joined: Feb 2003
Posts: 1,078
Likes: 46
From: Brighton
I assume that the airframe acts like a Faraday cage (even though it isn't earthed)
See Faraday cage - Wikipedia, the free encyclopedia
Joined: Jan 2011
Posts: 779
Likes: 86
From: Seattle
The prohibition could very well be due to the possibility of RF interference. Most receivers have a local oscillator (LO) which is mixed with the received signal to produce an intermediate frequency. Some poorly designed receivers/mixers allow this LO signal to radiate back out the antenna. Here, the danger is that this signal would be mixed with the sattelite signal in the avionics GPS and produce spurious results.
If the fear is that passengers will know the aircraft position, then what will they do as inertial navigation systems become accurate enough and are incorporated into personal gadgets?
If the fear is that passengers will know the aircraft position, then what will they do as inertial navigation systems become accurate enough and are incorporated into personal gadgets?
Joined: Dec 1999
Posts: 2,584
Likes: 0
From: UK
With respect I can't believe anyone actually believes that "they" don't want us to know where we are. (If so why would "they" allow windows?) Or GPSs for that matter.
That's straight from "we are controlled by lizards" territory.
LFOs and interference are the reasons.
That's straight from "we are controlled by lizards" territory.
LFOs and interference are the reasons.
Joined: Jun 2001
Posts: 4,369
Likes: 3
From: UK.
A Faraday Cage does not need to be earthed.
I first had the effect demonstrated when I built a radio receiver which failed to receive. Our techs tried an RF sig gen and 'scope on it - worked OK.
Took it home in disgust; it worked.
Ah! Steel framed workshop
Joined: May 2009
Posts: 1,909
Likes: 129
From: Here
Back in the day pre-wifi, before smart phones existed and other portable/handheld transmitting devices were uncommon (and therefore only phones were banned) I tried to use my satnav on a flight just out of curiosity. Couldn't get a signal.
Joined: Feb 2003
Posts: 1,078
Likes: 46
From: Brighton
every Faraday cage I ever worked in was indeed earthed. And to a pretty rigorous standard too.
Joined: Dec 2006
Posts: 50
Likes: 0
From: Belo Horizonte, Brazil
Many, many years ago I was passenger on a trans continental flight before GPS receivers were common place. I had recently bought a portable GPS receiver. I asked the flight attendant if I could turn on the GPS in order to follow the flight (it was an FCC approved model). She said that she would have to ask "the guys up front". She came back with a big grin saying that sure I could use it, but the "guys up front" would like to take a look. So there I was with my new toy and an enthusiastic crew because they could now file direct rather than follow the zig zag VOR path. The batteries ran out before reaching destination but that was no problem since the crew just reverted back to normal navigation. Interestingly, it worked well in the cockpit environment - 737, but I guess the larger windows helped. Happy memories!
Nice-but-dim
Joined: Sep 2001
Posts: 640
Likes: 0
From: Rural Yorkshire
Although admittedly risking getting my wrists slapped, I've 'accidentally' left the GPS switched on on my tablet on a couple of occasions (last time last weekend on a 767) whilst sat in a window seat. Took a good 10 mins to get a signal each time but it ultimately did with patchy results, sometimes only getting a single fix then unable to refresh, other times a good constant lock until I quit the map app.
Joined: Aug 2006
Posts: 42
Likes: 0
From: Chester, Cheshire, UK
Had an embarrassing moment with GPS on a flight a few years ago when I started my iPhone GPS based "Speedo" app "just for fun". It took a while to get a fix but when it did started to sound it's quite strident alarm! I'd forgotten that I had it's speed warning set to 80kph. We were doing over 800!
I didn't know GPS wasn't permitted during flight. I also assumed it was passive.
I have a very neat set of photos taken with an iPhone through the window of an A380 over Turkey which are all neatly tagged with their location. Pity not to be able to use that functionality.
I didn't know GPS wasn't permitted during flight. I also assumed it was passive.
I have a very neat set of photos taken with an iPhone through the window of an A380 over Turkey which are all neatly tagged with their location. Pity not to be able to use that functionality.
