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.

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

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 ...

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?

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....

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

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.

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'.