GPS

[jollyrog]

Professional opinions please on use of a GPS (Garmin) by passenger during flight?

I was asked to turn mine off by the CC last week. I immediately complied and asked why I'd been asked to. The CC said that "Any device which transmits a signal could interfere...". Fair enough, but I pointed out that a GPS doesn't and isn't capable - it just receives.

By then it was off and back in its bag. I was expecting that it would be left at that, but the CC then said she'd ask the Captain for a decision and off she went. Not my bidding.

Returned a couple of minutes later and said that the Captain doesn't approve. So, it remained off and in the bag, as instructed.


Irish registered aircraft on a European flight. Over France at the time. Seat belt sign not illuminated.

I didn't think I was breaking any rules when I switched it on - battery powered, not a transmitter, not in the restricted phases of flight, etc.

I prepare to be corrected!

Thanks.

[UniFoxOs]

My GF asked for permission (on a TUI Transatlantic flight), not that she wanted to use it as a GPS but because it is a handheld PDA and she wanted to use it as such. CC said OK immediately, so I guess the airline staff vary in their knowledge of the subject.

Speaking as an engineer, I know that ANY receiver (well nearly any if you want to be pedantic, as there is a type that doesn't but they are REALLY rare), GPS, radio, whatever, has a circuit called a local oscillator which will emit radio frequency waves. The magnitude and type of these is such that they are almost certain NOT to interfere with any of the a/c systems, but many airline staff are not trained to make that sort of judgement and err on the side of caution (and I can't say that I blame them).

However mobile phones emit a much higher magnitude of radio frequency emissions - and it appears these can be used on aircraft!!

UFO

[apaddyinuk]

The BA policy is that "Any device which sends or receives signals" may not be used when the aircraft engines are operating!!!! So as a GPS device receives a signal it would render it as a device which cannot be used.

Now some PDA units which are also phones and GPS type things also have "flight safe" modes which are allowed on some airlines like BA but others such as EI do not allow it!!!

[jollyrog]

Thanks to both contrinutors so far for the information.

This prompted me to look at Aer Lingus's web site, to see what their policy was.

Not expecting to find a reference to GPS at all, I actually found this:

Permitted in-flight but not during taxi, take-off, initial climb, approach and landing: Various devices listed, beginning with "Laptops with CD ROM or DVD drive" and including "GPS handheld receivers".

There's a further section on devices prohibited at all times, which begins "Devices transmitting radio frequency intentionally".


My initial thought when posting was that use of my GPS was possibly contrary to legislation. I didn't think to look for airline policy. It seems that I was compliant with that policy.

Although not surprised that the CC didn't know what the device was initially, I would have thought the conversation with me and subsequently the Captain would have cleared it up.

I'm still interested to hear what other aviation professionals think about this. I will be writing a polite letter to Aer Lingus now - At the time, I felt quite humilliated in front of the other passengers, as it appeared that I was doing something dodgy and had to be chastised. Not a nice feeling!

[TightSlot]

Speaking as Cabin Crew, the whole PED thing is a minefield - The sheer volume of variations in manufacturer design and performance of each kind of device renders individual decisions by crew members impossible. Squabbling with customers about the PED restrictions has become a more frequent, and more tedious part of my working life. Although not in this case, many customers have an incomplete understanding of the nature of their own equipment: Others understand very well, but simply refuse to accept prohibition. Against this background, the only safe and effective method to trap all the possible scenarios IMHO is a blanket ban.

The thing that always fascinates is - why is it so vital to make that phone call or connect that Blackberry now? It rarely seems to be a life or death situation, where a further delay in switching on for 10 minutes or less would result in human suffering? Are people really so busy and time starved that they cannot turn a laptop off 10 minutes before landing? Maybe I'm wrong - but I suspect that the number of people for whom time is actually this critical is far fewer than the number who believe it to be so, about themselves.

http://i25.photobucket.com/albums/c57/TightSlot/a_rant.gif

[SLF3]

The bit I struggle with is when the wheels are firmly on the ground and you are taking a scenic tour of Heathrow and they still won't let you use a mobile phone.

Which aircraft system are they using that it might interfere with?

[PAXboy]

Does it matter which system? What if it affects a system that is only used once in a blue moon? But is needed that day at that moment? If the engines are turning, the a/c is using dozens of systems to get you safely to your destination.

One of the simple problems is the characteristic interference that a mobile (c ell) phone makes when it is switched on that can be picked up on any audio system. When you are driving a car, you can here the noise on the audio speakers, just before the phone starts to ring, or receives a text (SMS) message. We have had many FC on here reporting that they hear that sound in their headphones when they are communicating with the tower. Not good.

Enjoy the leisure time, close your eyes and rest.

[EastMids]

I have a degree of sympathy with TightSlot's view. I'll bet that a fair proportion of laptops used by passenger in-flight have their wireless enabled (possibly by user ignorance), and even the newer generation iPods (e.g. Touch) have wireless internet built in, and thus are capable of "transmitting". But no one really yet thinks about insisting these devices are kept off throughout a flight. What next - iPods banned on long flights? Don't think that'll go down too well, but how does any layman really determine which transmit and which don't? Rules need to be sensible, not rediculous, in order to increase passenger compliance, but devices keep getting more sophisticated. The only realistic ways to solve the issue are (a) to ban ALL portable electronic devices in flight, including laptops and music players, or (b) sort out carefully what devices really mess with aeroplane systems, strictly enforce a ban on those, and let others like GPSs, laptops and iPods be used.

FWIW, I find it rediculous that a device that can actually be used for navigation in an aircraft - a handheld GPS device - without additional aircraft certification, cannot be used in an aircraft! That's not to say I wouldn't switch one off if I had one - just that in respect of GPS the rules are non-sensical.

A

[G-BPED]

SLF3 Quote "The bit I struggle with is when the wheels are firmly on the ground and you are taking a scenic tour of Heathrow and they still won't let you use a mobile phone.

Which aircraft system are they using that it might interfere with?"


Before 9/11 I was in the jump seat on the flight deck of a BA A320 for the landing into Berlin (TXL).

I had a headset on so that I could listen to the conversations between the pilots and ATC.

Just after we touched down and the pilot was talking to ATC as to where we would be parking the familiar sound of a mobile phone searching for a cell/signal broke through on the headsets.

The pilot had to ask three times for the taxy instructions to be repeated as the cell phone pulses were making the speech from ATC unintelligible.

I am sure you would agree that misunderstood/interrupted communications from ATC are not desirable at all.

Regards,

G-BPED

[EastMids]

The bit I struggle with is when the wheels are firmly on the ground and you are taking a scenic tour of Heathrow and they still won't let you use a mobile phone.

In more advanced civilisations like the USA :}, some airlines such as United do allow cellphone use after the landing runway is vacated up to the gate - in fact they go as far as to suggest passengers take cellphones out of the overheads before the seatbelt signs go for that very purpose.

Andy

[PAXboy]

If United want to have their pilots interactions with ATC/Tower interrupted, then they are at liberty to arrange it so ... :hmm:

The reason that hand held GPS are not permitted is due to the fact that it transmits. Any transceiver that is built into the a/c has a known RF characteristic and the systems have been built and tested to not interfere with each other. If you introduce another transceiver of unknown properties, then there is a risk that it will interfere. Yes, the risk is small but why take it.

I have just taken a 13 mile car journey and the risk of collision was not that high but I still wore my seat belt in case something went wrong.

As I say, close your eyes and enjoy the time out.

[jollyrog]

PAXBoy - I have been reading the comments with interest since my original posting and appreciate the answers.

The GPS doesn't transmit though - it's a receiver. I've used it many times when flying myself around (I'm a PPL) and so far, I haven't fallen out of the sky or been unable to speak with ATC because of interference.

I have also looked at several airlines web sites and both Aer Lingus (previously mentioned) and British Airways mention hand held GPSs specifically, with a permission to use them stated.

BA - "Electronic games, iPods, iPaqs, small radios, tape and disc players, miniature television receivers, GPS receivers and similar entertainment equipment have negligible effect on aircraft systems and may be used during flight, but must be switched off during take-off, approach and landing."

... which seems to contradict an ealier post that BA prohibit their use.

[EastMids]

Paxboy, I really don't give a toss about this because I don't want to use a GPS on a commercial airliner, but I have to follow up on your comment...

Thousands of hand-held GPS devices (i.e. not permanent fixtures of an aircraft) are used in thousands of aircraft every day, all around the world. Maybe not in the British Airways or American Airlines of this world, but certainly in both lower-level air carriers and in general aviation in all of its manifestations, from air taxis to single engined light aircraft. If you're seriously suggesting that such devices give rise to a risk to those sectors of aviation, then maybe the operation of such GPS devices should be banned in all aircraft? I suspect that many of the airborne applications for hand-held GPS involve aircraft with far simpler (i.e. old, unsophisticated and thus more susceptable to interference) avionics fit than the modern airliner in which the systems [presumably] have been somewhat more rigourously subjected to testing for suceptability to RF interference.

So, again, if aircraft from third-level airliners down to SEPs are not falling out of the sky or seriously suffering from avionics interference as a result of the use of hand-held GPS whilst in flight (including the aircraft I fly regularly), I'm still mystified as to why it should be an issue on airliners. And, as I said above, logic suggests that if you ban hand-held GPS, you should also ban laptops, iPods and pretty much all other portable electronic devices (my camera even has a capability to transmit wirelessly and not using IR) from use in the cabin.

A

[Contacttower]

The thing about GPS is true....it shouldn't be a problem. jollyrog I assume that your Garmin is designed for use in aircraft (do they even makes ones that aren't?) and you've probably used it hundreds of times in the air before.

I don't know whether the fact that it probably wasn't IFR certified has anything to do with this?

Mobile phones are a completely different issue though, I have on several occasions left my phone on in the cockpit by accident and heard that sound in the headphones when someone is ringing it. Interference with the autopilot and the ILS has apparently been reported in the past as well that was thought to come from mobile phones.

[TightSlot]

Given that the Cabin Crew are those charged with policing the PED restrictions, how do you all expect them to know what is, and is not, safe? One kind of GPS may be safe, another may be different, and therefore not safe.

Does it really matter? By this I mean, is the requirement to use a GPS in-flight actually worth all this internet searching, time and trouble - it seems such a minor and trivial imposition that I'm having trouble understanding why it might be a source of heat?

:confused:

[strake]

I'm having trouble understanding why it might be a source of heat?
Well, it's got batteries in it see? They store energy and then release it when the device is turned on...with me? Energy sort of moves around a bit and then, well...it gets hot!
Or did I misunderstand your statement....:8

[Self Loading Freight]

This is only going to get trickier, as gadgets get more complicated. Any digital device (and many analogue ones) emit low level radio signals during normal operations - hold an AM transistor radio next to your laptop - and as more of them get radio capabilities which may not be explicitly clear to the user it's going to be trickier policing them in flight.

GPS receivers should be safer than most. GPS signals are very weak, so the designers will have taken care to shield the incidental radiation from the electronics. That's just as well, really: I was talking to some engineers from Broadcom, a chip company, and they said that GPS is going to be a big growth area with navigation capabilities finding their way into all sorts of consumer electronics. With more seatback entertainment systems sporting moving maps, it's no longer quite as fun to use a handheld GPS during flight as it was, but the chances of your MP3 player, wristwatch or laptop having GPS can only get higher.

If there is a problem - and despite anecdotal evidence, I don't think there is - then the only solution I can think of is the worldwide adoption of a flight-safe certification scheme for portable electronics, with a recognisable logo on the case that can be shown to cabin crew, alongside a similar logo on the display that shows when flight-safe mode is enabled, if that's an option. It could be run like the CE, FCC or other approval procedures, where manufacturers self-certify and cop the blame if they lie.

Personally, I'd think this would good thing: I'd love to be able to use a radio receiver during flight to catch up with the World Service on HF, and while the ban on those is sensible given the way radios work it's quite possible to design one that doesn't cause problems.

R

[Techman]

The only problem is the "Who are you to tell me I can't do what I want to do" attitude that is so prevalent these days. Everything has to be questioned and argued. It is as frustrating to listen to as the "We didn't crash, therefore it must be safe" argument. An argument that can only be described as naive and uninformed.

The avionics in aircraft you will fly in tomorrow, will not have been tested for interference from internal sources, and most likely not even for the frequencies used by most wireless equipment. If you choose to use such equipment onboard, you will in fact be conducting an unsupervised experiment.

[Contacttower]

If there is a problem - and despite anecdotal evidence, I don't think there is - then the only solution I can think of is the worldwide adoption of a flight-safe certification scheme for portable electronics, with a recognisable logo on the case that can be shown to cabin crew, alongside a similar logo on the display that shows when flight-safe mode is enabled, if that's an option. It could be run like the CE, FCC or other approval procedures, where manufacturers self-certify and cop the blame if they lie.



That would be quite a good idea. I do agree with jollyrog about the GPS though, some interested PPLs may wish to have them on during the flight...purely for interests sake. One's Garmin isn't going to interfere and I'm slightly surprised the captain insisted it was off.


The avionics in aircraft you will fly in tomorrow, will not have been tested for interference from internal sources, and most likely not even for the frequencies used by most wireless equipment. If you choose to use such equipment onboard, you will in fact be conducting an unsupervised experiment.


Whipping out my 496 during the flight is not an 'unsupervised experiment' at all. While of course one should always do as you are told by the cabin crew and never argue I think if you have an aviation GPS and want to use it during flight there is no real reason as such why you shouldn't. Mobile phones are a completely different matter though and I think even if they are ever proved safe (which I don't believe) they should be banned anyway....if only to preserve peace and quiet.

[radeng]

If the GPS receiver is a direct conversion type, then the biggest possible cause of interference is to the on board GPS. Not desirable. But if it's a superhet, then we have a potential problem. If it meets FCC (US) requirements on oscillator radiation, it could well have an Intermediate Frequency such that the local oscillator blocks a DME channel. If it meets EU standards, possibly not - but only possibly, depending upon which stanadrds the manufacturer has decided to declare it compliant to.
As far as cell phones are concerned, any LO radiation if the receiver uses high side injection could kill a DME channel. A complication arises in that the immunity of cabling on a nice new aircraft is quite likely to be different to that on a 10 or 20 year old aircraft where corrosion, movement etc have happened.
The problem is that as far as aircraft systems are concerned, you KNOW what frequencies are involved. Bringing in unknowns (because you DON'T know the frequency plan of every possible bit of equipment) is another matter. Add to that the fact that there isn't just the fundamental radiation to worry about, but the presence of intermodulation products when authorised transmissions are made from the aircraft, there is a VERY good reason for banning the use of these things.
If you wonder about my qualifications, 'radeng' is a reduction of 'radio engineer'.

[Contacttower]

If the GPS receiver is a direct conversion type, then the biggest possible cause of interference is to the on board GPS. Not desirable. But if it's a superhet, then we have a potential problem. If it meets FCC (US) requirements on oscillator radiation, it could well have an Intermediate Frequency such that the local oscillator blocks a DME channel. If it meets EU standards, possibly not - but only possibly, depending upon which stanadrds the manufacturer has decided to declare it compliant to.



radeng I don't know much about the technical stuff in detail but are you saying that if I fly along using the panel mounted Garmin 430 (or whatever) and I've also got a handheld on the yoke...you know just to cross check stuff and perhaps do someone with one while the other shows something else...they might interfere with each other?

[PAXboy]

ContacttowerWhipping out my 496 during the flight is not an 'unsupervised experiment' at all.OK, what is it that you are doing then?

While of course one should always do as you are told by the cabin crew and never argue I think if you have an aviation GPS and want to use it during flight there is no real reason as such why you shouldn't.So: you will do what the CC tell you to do and never argue ... unless you decide not to do what they tell you and to argue because you think that there is no reason to obey them?


Over the years that this topic (transceiver devices in the cabin of commercial aircraft) has been discussed in PPRuNe, I have always put forward a cautious view. I have suggested that, since we do not know the possible outcomes AND that folks like radeng advise against it, AND that we hear reports of interrupted FD comms, that we should not rush to use them. For this, I am regularly castigated, which I find curious.

Yes, it is confusing when different carriers have different instructions about hand held devices. Well, the rules are the rules and if one carrier says they permit them on their A320s or B777s and another operator of the self same a/c does not - then that is the way it is.

Whether or not folks pilot their GA machine with two GPS units strapped to their goggles - I care not!! When aboard a commercial transport, you follow the rules of the company that you are paying to get you to the destination. That is the same if it is a taxi, a ship or an aircraft.

Do I think the risk of using a transceiver in the cabin is low? Yes. But the risk is unknown and I would like to see air travel continue with its high safety record.

[Contacttower]

OK, what is it that you are doing then?

Well these systems have been in use for a while in aviation, they were designed for use in aircraft and as far as I know do not interfere with any of the other systems. The fact that I decide to use it on a plane that is just a bit bigger shouldn't make a difference. A lot of GA types have 99% of the equipment in a modern airliner anyway and they don't seem to have a problem.


So: you will do what the CC tell you to do and never argue ... unless you decide not to do what they tell you and to argue because you think that there is no reason to obey them?



PAXboy this is the place to have the arguement...not the cabin of course and I say again I would never argue...as it happens I've never felt the urge to take a GPS with me on a flight and probably never would...but I can understand why some PPLs/spotters or whatever might.


Permitted in-flight but not during taxi, take-off, initial climb, approach and landing: Various devices listed, beginning with "Laptops with CD ROM or DVD drive" and including "GPS handheld receivers".



Some airlines think they are safe anyway...


Whether or not folks pilot their GA machine with two GPS units strapped to their goggles - I care not!! When aboard a commercial transport, you follow the rules of the company that you are paying to get you to the destination. That is the same if it is a taxi, a ship or an aircraft.



That is of course the bottom line...follow the rules.

[Contacttower]

While of course one should always do as you are told by the cabin crew and never argue I think if you have an aviation GPS and want to use it during flight there is no real reason as such why you shouldn't.



So: you will do what the CC tell you to do and never argue ... unless you decide not to do what they tell you and to argue because you think that there is no reason to obey them?



Sorry I didn't phrase that very well- just to clear this up I didn't mean to imply that you could ever disregard CC if you thought it was safe to do so, I was just saying that personally I don't think GPS effects safety.

My interest in this thread is not because I want to use a GPS system during an airline flight but because if there is an interference problem that would have very serious implications for a lot of GA types who use handheld GPS alongside radio nav avionics.

[PAXboy]

Fair enough Contact, I see your approach (if you will forgive the pun!). For the sake of debate then, you will see why these statements catch my attention (my italics):
... they were designed for use in aircraft and as far as I know do not interfere with any of the other systems. The fact that I decide to use it on a plane that is just a bit bigger shouldn't make a difference.Fine that you don't argue with CC but we know that others will, or will use transceivers clandestinely. The problem with commercial airline safety is that is taken as a given by many (not all). It is a well known bit of modern marketing history that flying was promoted as easy as boarding a train to fill all those lovely wide bodies and now ... people think that they are boarding a train.

It's late, I'd better get some :zzz:

[Self Loading Freight]

It's always possible that electronic gadgets can interfere with aircraft systems, even if everything's well designed - there are an infinite number of fault conditions on both sides that can mess things up (I had an audio amp that oscillated wildly at VHF if the speaker cables were too close to some of the inputs - that blocked out my local FM reception for a while).

The question is - what are the probabilities? A well-designed GPS receiver, even if it is direct conversion (didn't they used to be called regenerative receivers, RadEng, back in the day when the BBC used to broadcast requests for the listener in Ealing causing complaints to back off the reaction knob? :) ) will have LO radiation figures well down, and all of the antennas for the various RF avionics will be on the other side of the skin to the pax. And broken shielding or other cabling or connection faults within the a/c will presumably increase the probabilities of interference from various sources, including other avionics, so should be fixed.

Any radio system that is mission critical has to be defensively designed, and that includes coping with rogue carriers and other non-desired energy at the input. Fortunately, especially these days, there are lots of techniques to help with this, and any regulatory regime for approval should reflect environmental reality.

Another way of looking at it is that if vital systems are vulnerable to interference from normal consumer electronic devices, then they'll be exceptionally vulnerable to deliberate attempts to attack them from modified equipment. A naughty person skilled in the art could pack a lot of unpleasantness into an iPod case...

R

[radeng]

Difficulty number 1:
One type of GPS may be direct conversion (that's not regenerative, by the way - it's sometimes called 'zero IF') and not radiate and another may. especially if we start talking about cheap imports from the far east, where despite all the so called rules, compliance with EU and other standards may well be imaginary. So you DON'T know, except by experiment, and when you add up all the possibilities in a modern airliner, with all the variations of stuff pax are carrying, the possibilities of interference multiply very quickly. In fact, if you have N signals, the simplest combination (3rd order distortion for the techies) gives 2N(N-1) possible interfering signals.
Difficulty number 2:
Aircraft cabling does degrade over the years, and it's a well known phenomena. It's not always possible to determine by visual inspection if the shielding is complete, or that there's no corrosion, and complete rewiring every year just would be too expensive.I seem to remember an article in IEEE Spectrum a few years ago in which they said something like a 767 has over 70 antennas, and I can well believe it. So there is a fair amount of careful; design goes in in the first place in frequency planning in aircraft installations and so on to minimise the problems, and the introduction of just one extra emission can cause problems.
By the law of Arkwright Sod, it won't happen in every situation. It won't happen every time in the same aircraft. The trouble is that it may only need to happen once. Just as back in the early '60s, some guys in Norway misread the Morse ID of an NDB and flew into the side of a mountain.
Radio systems are always liable to interference. I can readily conceive of easy to make things that could cause chaos around airports and for obvious reasons, I'm not going to say what or how here. A radio link required to be out for no more than 10 seconds a year has a dedicated frequency and hot stand by equipment. But at the end of the day, you can't guarantee a radio link - you can just do your best. It's because of the interference that major UK airports have specialist interference trackers available all the time. But that doesn't mean that you can throw another parameter into the mix and get away with it.
And to re-iterate, cheap imports from the far east frequently do not meet any of the compliance standards even though they are supposed to do so. Some companies just ignore the rules, including one major UK telecomms firm! All too often, CE on a product just means 'chinese export'.

[Contacttower]

... they were designed for use in aircraft and as far as I know do not interfere with any of the other systems. The fact that I decide to use it on a plane that is just a bit bigger shouldn't make a difference.


You are right with your cautious approach....I'm never going to say they are 100% safe because you can never be 100% sure with anything. But personally I don't have a problem with people using them. Mobile phones is a completely different matter though and personally I think they should always be banned. And as for transceivers in the cabin one is probably breaking the law.

[PAXboy]

I took a long break before replying Contact and am trying to avoid making this too personal but ...

Did you read radeng's post? Here is a professional RADIO ENGINEER, taking time to explain (again) why the use of untested electronic equipment on commercial aircraft is undesirable and your reply?
I'm never going to say they are 100% safe because you can never be 100% sure with anything. But personally I don't have a problem with people using them.So you don't have any problem when a radio engineer does have?

To show more confused thinking, you then state that mobile phones are a completely different matter and should be banned (to try and exclude your little toy from the ban) and complete your grand sweep by saying:
And as for transceivers in the cabin one is probably breaking the law.If a device generates and receives radio frequencies, it is a transceiver. That means that your GPS unit is a transceiver, which is why I used the term. (some devices are transmitter-receivers and some are transceivers but they both generate and received RF)

[strake]

If a device generates and receives radio frequencies, it is a transceiver. That means that your GPS unit is a transceiver, which is why I used the term. (some devices are transmitter-receivers and some are transceivers but they both generate and received RF)
Paxboy, I think you need to look carefully at what you are writing...you're begining to confuse yourself. What is your definition of the difference between a transmitter-receiver and a transceiver?
A Garmin portable GPS, certainly for aviation purposes, is a receiver. From his note, that appears to be what the guy had on board. It is also tested for emmission safety by Federal and US and other authorities. I know this because I can read it in the documentation supplied with my Garmin GPS.
And it's no good getting all huffy about people posting their opinions on here..for all we know Radeng is a 75 yr old googlespert granny with time on her hands....

[Contacttower]

Did you read radeng's post? Here is a professional RADIO ENGINEER, taking time to explain (again) why the use of untested electronic equipment on commercial aircraft is undesirable and your reply?



Nothing personal taken...I did read radeng's post and of course I'm not going to disagree with him...but if I took the line that everything could interfere with anything in a plane then I'd fly around with nothing but a whiskey compass, which would be silly!

It is also tested for emmission safety by Federal and US and other authorities. I know this because I can read it in the documentation supplied with my Garmin GPS.


Exactly, GPS sytems like the one orginally asked about have been tested for use in aircraft. :ugh:

To show more confused thinking, you then state that mobile phones are a completely different matter and should be banned (to try and exclude your little toy from the ban) and complete your grand sweep by saying:

With respect, I am not confused about this at all...in the aviation world a transceiver is radio device (usually handheld in this case) which transmits speech on VHF or UHF frequencies (spotters use them to listen to ATC around airports and I carry one with me in the aircraft in case the main VHF unit packs up or I crash).

GPS systems are considered something completely different. If you read the sticky at the top of the ATC forum you will see why use of a VHF transceiver to listen to ATC may be illegal with the exception of airshows for example. The reason I wouldn't recommend using them on the aircraft is that they have the potential if the PTT gets stuck to block the frequency being used without the user knowing...which would have very serious implications.

Mobile phones are again something completely different, as well as radio interference there have also been reports of interference with the ILS and autopilot (among other things) and someone else mentioned DME in the 'Tech Log' forum. But GPS hasn't been known to cause anything like that in GA aircraft and I have no reason to believe it would on an airliner.

Back to the original point....I have no interest in using a GPS system or as you call it 'my little toy' on an airline flight...but the orginal poster asked a fair question and I number of people have answered that it shouldn't be a problem.

PEDs are a pain for CC and I would completely understand a blanket ban.

[PAXboy]

With regards to Transmitter/Receiver and Transceiver, I was going on a fairly pedantic definition which I shall not bore you with.

strakeAnd it's no good getting all huffy about people posting their opinions on here.. for all we know Radeng is a 75 yr old googlespert granny with time on her hands....Sorry if I sounded thus, I was trying to find the dividing line at which the correspondent decided what was, and what was not, permissible (and by who's judgement) and found it.

Having enjoyed PPRuNe for 6.5 yrs, I am well used to opinions being expressed and relish such. Indeed, I suspect that I am thought of as being opinionated myself ... :}

Reading Radeng's posts (who signed at the same times as I did but I am more verbose than he!) across that time leads me to trust what he says. I, of course, could just be an awkward teenager who enjoys winding everyone up and watching them fulminate. :p

[radeng]

radeng is 60 years old. His father was a radio ham, who spent 3 years teaching radio at Cranwell during WW2. radeng took the radio amateurs examination on his 14 th birthday, and entered the profession in 1964. He has some 23 patent applications to his credit, 28 published articles/papers and is chairman of an international standards committee - happens to be on medical implanted wireless systems - but that doesn't alter matters. He has chaired 2 international conferences, and served on the papers committees of 4 more. radeng is also a Senior Member of the IEEE, and a reviewer for articles for the IET Electronics Letters and IET Transactions. Not quite a 75 year old granny! Mind you, the current medical problems are such that I'm not quite sure.......
Heathrow Director knows who radeng is....
Yes, a Garmin may well be no problem. But CC are not going to have a comprehensive list of which equipment is acceptable and which isn't. And in these days of clones, even such a list is a problem.
I must admit I haven't studied in detail which standards apply, but I suspect that under the regime of the Radio and Telecommunications Terminals Equipment Directive, I can legally put on the market a GPS equipment meeting the requirements of EN55013. That allows a local oscillator radiation of -13dBm or 50 microwatts. To put this in perspective, the typical sensitivity of the VHF comms is around -100dBm or 10 to the minus 13 microwatts - i.e 0.1 pico watts. And as the regime in Europe for determining compliance is pretty well non existent except partially in Germany - and even there a bit spotty- who is going to enforce things?
The difficulty is that with a wide range of possible different equipments, who knows what frequencies and levels are involved? Even with cellular, there are several different architectures and thus frequency plans.
The problem at the end of the day is that you DON'T know. And if there is a problem, it may be too late to find out......
Interestingly, at the standards meetings where they discuss mobile 'phones on aircraft, you must remember that a lot of the people there spend a lot of time flying. And they are all against it!!! Their employers may want it, but the guys who are going to have to put up with it don't want it at all......
There is an expressive French term for it. "C'est un bordel".

[strake]

Hmmm, radeng...I'm not sure you've covered that as comprehensively as you possibly could. Still suspicious...these Granny's are clever. Maybe you and Heathrow Director are part of the same Darby & Joan club?
Now, please explain how electricity works:p

[Self Loading Freight]

Just for fun, here's a link (http://www.ips.gov.au/Educational/1/3/10) on how the sun can interfere with GPS...

[TheChitterneFlyer]

I sometimes enjoy following an interesting thread, particularly within the SLF section, because someone somewhere will produce an informative and professional viewpoint. However, I do despair when good info is provided by an expert in his field and yet those answers never seem to appease those who simply can't accept NO for an answer.

Good reply radeng...

[Desk Jockey]

Hmmm, radeng...I'm not sure you've covered that as comprehensively as you possibly could. Still suspicious...these Granny's are clever. Maybe you and Heathrow Director are part of the same Darby & Joan club?
Now, please explain how electricity workshttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/tongue.gif


A bit late to answer that one but essentially electricity is just smoke inside the wiring. This is proved by the fact that if you let the smoke out the circuit stops working.
Best to keep that gps switched off then.:E

[radeng]

Technically, the smoke is in the components. When they fail, it may cause the wiring to smoke as well.

At the age of 63, I've only been making a living out of radio engineering since 1964, and I built my first radio 57 years ago......I chair a European Standards committee on radio equipment, published some 37 different papers and articles, generated 23 patent applications, have consulted for UK DTI as it then was, referee papers for the IET (used to be the IEE), and represent another organisation at the International Telecommunications Union, so I claim some knowledge.....

I still say it's better to keep the damn thing off.

[Desk Jockey]

Built mine in 1965 and not progressed much since then but of course I'm only a G7 :E

I did have a play with my GPS once on a trip to the US but not much to look at on a Garmin E Trex! As far as portable radios are concerned there is so much electrical noise in a modern airliner it's a bit of a waste of time.
Just sit back and enjoy the movie and food. (Especially if someone else is paying) :ok: