Passenger use of GPS

[Mr Optimistic]

Can someone tell me what the general policy is these days regarding the use of GPS devices by passengers during flight? Tried to search forum but couldn't find the 'search' option (I know I am going to regret admitting that)

[Bullethead]

I know you're optimistic but you might have trouble getting a decent signal inside an airliner.

General policy for any electronic device is in the cruise only, but people still use video cameras during take off and landing etc.

Personally I can't see using a GPS in flight being a problem as it is only a receiver but the rules is rules. :rolleyes:

Regards,
BH.

[nicolai]

It seems to be very variable between airlines as to whether the use of GPS units is permitted in-flight. They do, at least, usually list them in the inflight devices information these days.
As to whether they work or not, it can take quite a while to get a fix (from a cold start, I expect because downloading the almanac is marginal) but once fixed the position updating seems to work OK. It's usually necessary to hold the receiver by the window, and at the window most GPS units seem to see 4-5 satellites.
On airlines which permitted it at the times I was onboard, I've used both hand-held dedicated GPS units and GPS units in a mobile phone and got a position fix, as well as a plausible ground speed and altitude. I should note that the phone I used was capable of having the mobile phone transmitter offline ("flight mode") while having the GPS receiver on - clearly one would not want to use a phone that cannot receive GPS without transmitting mobile phone signals as that would be against regulations.

[Been Accounting]

Some people have made it work! I assume he must have had the antenna near the window (as the photo suggests).

If you are a google earth fan you might have seen this ...

Ogle Earth: Tracklog to timeline with KML's <TimeStamp> (http://www.ogleearth.com/2006/09/tracklog_to_tim.html)

[Mr Optimistic]

...read about using GPS in some magazine or other, apparently works if pressed to window as suggested above. Probably if used immediately before flight, acquistion might not be too long. Just don't want to be shouted at by CC as I'm easily embarrassed !

[Bullethead]

If you don't want to be embarrassed ask the C/C if you can use it and they may ask the Tech Crew and if you get the nod then great if not then read a book. :p

Regards,
BH.

[Final 3 Greens]

I asked for permission to use it on Aer Lingus, pre 9/11.

CC asked capt. and I was invited to demonstrate GPS in flight deck.

Stayed all the way to Dublin.

An it worked surprisingly well, despite coating on windshield - mind you it had a cable antenna, wchih may have helped.

[Union Jack]

Stayed all the way to Dublin

I trust that was where you were going!:ok:

Jack

[Sgnr de L'Atlantique]

Just watch out for a possible MAPSHIFT. Most hand held GPSs are not designed for the high speeds we fly at and can experience a significant map shift. This will be irreversible and damages your handheld.

In all cases always ask the CC if you could use it, if you want to avoid unnecessary problems!

[10DowningSt]

In all cases always ask the CC if you could use it, if you want to avoid unnecessary problems!

Why, I wonder. They are electronically inert, as someone has pointed out. In other words they represent no more risk to aircraft safety than a Biro pen, and perhaps less than an Ipod.

If the reason is that the CC are not aware of that and must not be alarmed, it would be a good idea to tell them.

It's far too easy to say "Ask permission", when doing so is actually totally unnecessary. You'll be recommending asking permission to read a book next, just in case the CC think that's a dangerous activity.

Of course GPS usually doesn't work in the cabin, and the MAPSHIFT problem is a real one. But that's not the point! There's no reason to stop anyone trying.

[TightSlot]

One reason for asking the CC is a quaint old-fashioned thing called courtesy.

Sadly, most CC don't share the depth of knowledge about GPS that you do. Given that both technology, and the specifications of models within established product ranges change all the time, it is unreasonable to expect CC to be au fait with each individual product. You may be an expert, or you may just have read the manual during taxi-out: CC have no method for assessing your individual level of expertise or the specification of the product. They do, however, have a reasonably good working knowledge of the various regulations and policies that are in force at the time. Those regulations and policies are in place to attempt to ensure a safe journey for yourself and your fellow passengers - they have been created by people whose depth of knowledge of aviation safety can be publicly demonstrated. How dare you sneer at those people, such as Cabin Crew who work to keep you safe.

Speaking of expertise - may we all know yours. You have stated that a GPS poses "no more risk to aircraft safety than a Biro pen, and perhaps less than an Ipod". Is this an approximation of the facts, totally accurate or an educated guess? I'd suggest that the latter is likely to be the case, but I stand to be corrected. Given your attitude to CC, it would seem likely that you're not actually a pilot either - meaning that your statement about asking permission is nothing more than a petty rant from somebody who simply resents any kind of imposition being placed on them by anybody or anything else.

Parents of 2 year olds will be familiar with this level of behavior.

[PAXboy]

10DowningStThey are electronically inertActually, they are not! Every single item of electronics gives out radio frequency signals. They might be at a low power level, but the risk is not incidental.

Mr Optimistic The forum FAQ has links to threads about the use of electronic apparatus whilst on board and as TS says, ask the CC.

[10W]

I left my Garmin Nuvi on by accident in my jacket pocket placed in the overhead bin on a recent trip from SFO-LHR. On returning home, there was a nice display of our track outbound and up over the Great Lakes. The trace stopped around YYZ, where I guess the battery power gave up.

I also got a new record high speed on my database ... 697mph :ok:

For non accidental use, I'd ask the cabin crew of course :cool:

[Mr Optimistic]

its just nice to know what you are looking at ...now off to look up 'map shift' ??

[Dee747]

Have successfully used mine, once in the cruise (and with the benefit of a window seat) routing BFS-NCE and return. Passes the time nicely, especially if the weather conditions allow a view of the ground. Max Speed recorded was 555mph (not as good as the 697 mentioned above mind you), and best fun of all was as we flew directly over the speed camera locations. Almost constant "pinging" from the satnav as we persisted in exceeding the various 30mph/40mph/50mph speed limits from overhead Folkestone to Blackpool.

[Pax Vobiscum]

10W 697 mph? Assuming a cruising speed of Mach 0.83, that equates to (counts on fingers) a 150mph tailwind. Not impossible, but pretty extreme even in the jet stream. Or is my arithmetic letting me down (again)?

[clareprop]

As I found out by accident last week, the GPS/Maps application on a Blackberry still works when in flightsafe mode.

[raffele]

Pax Vobiscum - I've flown back from the states in a jet stream of around 150mph before - the moving map showed a ground speed of 720+mph for a good portion of the flight (the max was around 735mph), so definitely not impossible!

[m_j_berry]

Pax Vobiscum: I've also been lucky enough to arrive at JFK a full 1 hour early from SFO, thanks to a helpful jet stream (tail wind about 150mph AFAIK).

In fact, before I fly I have a quick look at weather.co.uk, which includes jet stream maps (sorry, I can't get a permanent URL for the map, look under "Maps"). It's useful for guesstimating delays, and even though I always buckle up (of course!), also sometimes gives a hint of where you might get a bit of turbulence.

I expect others here will know where to get better maps than those though.

Mike

[Bushfiva]

This will be irreversible and damages your handheld.

Er, I don't think so!

[barstow]

PAXboy: For all intents & purposes, on board a passenger aircraft the "inertness" of a GPS receiver can pretty much be relied upon, as the IF level possibly radiated by the antenna is not only at a miniscule level (compared to say digital broadcast towers spewing out harmonics everywhere that the aircraft navigates over with no problem whatsoever), but at a frequency that goes nowhere near instrumentation/navigation receive frequencies. :ok:

I think the main reason that many airlines don't want you using your GPS on board, is that they have no control over whether the unit has been modified, or is still in spec.

I have used a GPS receiver on SAS, Swiss, and Cathay after consulting the CC. No US airline (that I have asked) has allowed me, nor Qantas or BA.

[xjimten]

I've used a laptop with Oziexplorer and USB Pharos GPS (got it with Microsoft Streets and Trips) and generally have good reception with the GPS stuck to the window. In moving map mode got altitude, GS etc
I travel mainly in Canada and have asked CC in both Westjet and Air Canada - in both cases they went and checked with flight crew and got permission no problem.

[Sultan Ismail]

10W & Pax Vobiscum

Referring back to your gps read out. 697mph is a typical figure for Eastbound flights in a jetstream, I have made many flights from Zurich to Bangkok with the indicator pegged on 1111kph (690mph). Needless to say it doesn't work the other way!

[smith]

Assuming a cruising speed of Mach 0.83, that equates to (counts on fingers) a 150mph tailwind.

PAX

Mach No. depends on Outside Air Temperature and hence Air Speed varies with Mach at different temperatures. Some jet streams can have speeds of 250-300kts.

I know flights comeing across the pond to the UK slow their airspeed right down as yes it would be nice to land early but they would not have a gate to go to.

[Mr Optimistic]

mingalababy, you take pictures of the gps screen in flight ? Is this common in Australia ?

[mingalababya]

mingalababy, you take pictures of the gps screen in flight ? Is this common in Australia ?

Mr Optimistic, have a look at this thread (http://www.pprune.org/dg-p-general-aviation-questions/378447-737-800-service-ceiling.html)on the DG&P forum. I believe some Qantas flight crews have responded to the question of whether it's permissible to use a GPS on board or not.

To summarise that thread, if the GPS is a receiver only, then it's ok to have it on at all times (incuding during take-off and landing) (despite what it says on the Qantas website about GPS systems). But of course, it is up to the Captain of the flight as he/she will have the ultimate say.

[Mr Optimistic]

...thanks, what a terrific thread ! Haven't been all through it yet. Didn't see any mention of reference ellipsoid either, surprising as I thought that's how gps goes from earth centic cartesian to map + height.

Some of these threads can get surprisingly energetic: begining to wonder why some std pax abuse isn't included with the initial formalities ('..will you clowns please pay attention, even those of you who can't read and paid a stupidly small price for the service we provide..'):O

[Capetonian]

Here's a previous thread on the same topic :

http://www.pprune.org/spectators-balcony-spotters-corner/212535-passengers-using-handheld-gps-receivers.html

[radeng]

barstow,

What about local oscillator radiation? There's not just the IF to consider - which itself can be a pretty big signal at the detector, as well as the radiation from the digital processing stages. That will depend more on the level of integration and the CMOS geometry used - to some extent, the geometry defines the supply voltage and thus the logic voltage swing. Very small geometries mean low voltage, but in complex circuits, leakage currents can be big enough to make a larger geometry more attractive.

A lot depends how the particular device is classed by the manufacturer under the EMC Directive: portable broadcast receivers have no limts (EN55013), while car radios have to meet -57dBm below 1GHz and -47dBm above. Those limits apply to general receiver radiation too, to meet Eu requirements. (ERC REC 74-01, implemented in all ETSI Standards -that will apply generally to cellphones). The US is somewhat less stringent. (CFR47 Part 15). If a Chinese make, the CE mark may just mean 'Chinese Export', with no attempt at meeting any EMC or spurious emission limits. Or it may be very good.

[Peter Fanelli]

Why, I wonder. They are electronically inert, as someone has pointed out. In other words they represent no more risk to aircraft safety than a Biro pen, and perhaps less than an Ipod.


Not true.
I have personal experience with a Garmin 100 used in a Cessna 310 which would prevent communication on HF as long as the Garmin was turned on.

[Capot]

Took a long time to catch up on that one, didn't it?

Not many Cessna 310s with HF comms these days, and even more surprising that a Garmin GPS would prevent the use of it. We live and learn, don't we.

[strake]

Maybe we can solve this once and for all?

Certainly Virgin, perhaps other carriers allow you to have handhelds operational if in Flightsafe mode.
Blackberry Pearl with cell tx/rx off (Flightsafe) GPS function still works.
Turn it on, hold it to the window and go "AAaaahhhh..." as it displays a speed of 550+MPH in the cruise and loads a nice little map showing you just where you are.

[smith]

I used my Garmin 96 on a Ryanair from PIK-STN last week and it worked fine, didn't need to "press it against the window" to get a proper signal but picked up more satellites if it was close to the window,

Pretty much good fun and a good way to wile away the trip. My readout was 455kts and pilot said we'd be flying at 37000ft and readout was 37263ft, due to flying flight levels and pressure varience. All good fun, I'd recommend it.

[Di_Vosh]

I have personal experience with a Garmin 100 used in a Cessna 310 which would prevent communication on HF as long as the Garmin was turned on.

Peter, with respect, that sounds more like a wiring/fitting/antenna issue than the actual GPS function of the Garmin 100 interfering with the HF.

All the Garmin 100's I've used were specifically designed aviation dashboard-mounted GPS units.

Not many Cessna 310s with HF comms these days,

Plenty in Oz GA.

Cheers,

DIVOSH!

[Mr Optimistic]

flying from Luton to the IoM I think the a/c moreorless flies over my house and I wanted to know when and which way to look. Hadn't figured on a global response. One thing that may be relevant is that there is always the possibility of modified gear. So whereas shop-bought stuff should be OK, perhaps chipped equipment is untested and unknown.

[Xeque]

I have used both my Garmin hand held a/c GPS as well as the Nuvi for my car (in off-road mode) during flights and both have worked well albeit after a little while to acquire satellites. I did this in plain view of CC with no problem.