Mobile phone signal interference... all lies??
 

I read here some time ago, from a number of posters, that the concerns about mobile phones being used in-flight were all justified - and that they could interfere with flight controls. However, I was subsequently told, by the pilot on a private jet (737), that was rubbish and we were allowed to use our mobile phones until they cut out. He suggested the ban related merely to agreements between airlines and mobile operators/carriers and regulatory bodies and that safety was just the most compelling excuse.

Now airlines are planning to allow in-flight mobile phone use it seems to further contradict claims that mobiles can interfere with important flight controls.

What are the real issues around this? I'd be very interested to hear from pilots and understand what controls will be in place.

Also, isn't there a risk that antisocial mobile use is going to further raise the tensions on-board and increase risk of passengers disagreements?

Please post your replies or feel free to email [email protected].

Best regards and keep up the good work!

Turn your mobile phOne on and stick it near to your PC. Then listen to the speakers as the phone signal inbound/oubound makes seriously annoying noises as it interferes with bits on your PC.

When phones are used on aircraft, quite often - admittedly not always - that same dreaded noise comes through the radio.

Now my aircraft is not a 737 and has a lot of computers on it. So forgive me if I totally support the non-use of something that interferes with computers.

It's a phone.......learn to live without it for a short while now and then.

Think of the worst scenario.
550 people (or whatever no of pax it carries) on board the A380 using mobiles at the same time.

Forget for the moment the interference to equipment, think about the radiation bouncing around it that tin can.

Turn the thing off and get a life.
The last thing I want to hear sitting on an a/c is someone beside me on a phone.

Mobile phone interference
 

AIrbuss clearly wrote to pilots that there is not a proved relation on microwawes interferece on computers flyght control wahtsoever (done by mobile phones), however the use is cautelatively requested to be restricted. Personally I will be very bother (more than that computers) if someone use a cell phone on board.
Is not a restaurant, is not a club, is not a bar IS A PLANE! Enjoy the flight!

A tad harsh.

There is more journo bashing about misinformation on this site than you can poke a stick at...here is someone asking a civil question and providing you with a chance to say your piece...be nice.

:ugh:

I think this thread brings the whole topic of air rage to light again,
as worldwidewolly says, the last thing I and probably most people want on a plane is someone yakking on a mobile :ugh:

Have a look at this thread, some very good references and articles:

http://www.airliners.net/discussions...ad.main/93818/

Has the theory about EMP from a phone searching for a network at max power possibly contributing to fuel-tank sparking (TW800, TG 737 on the ground at Bangkok) been fully debunked?

SLFGuy - I may be wrong but I don't think the "Get a life" quote was aimed at the poster. I read it as being aimed at mobile phone users in general when they refuse to be separated from it for more than a minute.:ok:

Will,

I have certainly heard mobile phones attempting to log-on to a service network over my headset whilst talking to ATC, it does interfere with communications.

regards,

fb

no offence taken...
 

I think you're absolutely right about an increase in air rage... there was an incident on a flight I was on last week (SFO to LHR). 11 hours drinking, little sleep, cramped conditions... and then throw somebody talking loudly on their mobile phone into the equation and it's a recipe for trouble.

On the technical side, is the distinctive sound of the EM interference an annoyance or could it pose a risk?

Get this, I once had my phone next to my hi-fi controller. The hi-fi was off, somebody rang me, and my hi-fi turned on. On another occasion it affected my PS2 whilst it was close to the controller and somebody sent me a text.

So in a nutshell, I think phones should be switched off. Or at least, in flight mode which is an offering on some of the later phones.

See here for more info.
http://www.house.gov/transportation/...20-00memo.html

Essentially nothing has been proven. However, aircraft are built to exacting standards, particulalry with regard to electrical interference. This considerably increases the cost of building - all for the safety of the people on board. The mobile 'phones are not built to anywhere near the same standard, and potentially reduce safety, at no cost at all!

I believe it is also an offence to operate an airborne radio transmitter without a licence.

Finally, an airborne mobile phone can reach several transmitters (line of sight transmission). Apparently, this is not a good thing for the 'phone providers.

GB

as mentioned in earlier replies, radio frequencies do interfere with one another..decades ago ....radios needed to be sheilded from the spark plug in a car(pardon my analogy...for want of a better one at the moment).
by radio frequency I mean all sorts of radiations...
my point....even though nothing conclusive against its use,I suppose the industry prefers to err on the positive side

That demonstrates that it interferes with audio signals. If you can reliably demonstrate that it causes the programs on your PC to malfunction (which might take only one bit to be changed in RAM or on disk) that would be much more impressive.

As I mentioned in another thread, the theory by which cellular networks have trouble or even can be crashed by airborne handsets, is totally false. Such networks and its components are built to be rugged and resilient. If anything like that may have happened in the past (altough I have no notice), it is certainly not happening today as the necessary changes in software have certainly been made a long time ago.
Not even at level of audio signal. GSM merely interferes with the speaker coil itself. That is why you can hear the noise even if interferenced device is off.

http://www.exponent.com/about/docs/cellphonereport.pdf
http://www.motorola.com/mot/doc/0/203_MotDoc.pdf
http://www.ericsson.com/ericsson/cor...olStations.pdf
http://www.ctia.org/content/index.cfm/AID/1040
http://www.ou.edu/engineering/emc/projects/AV1_X.html

There have been numerous threads on this topic, so I apologise for boring some of you who may have read this before!

My guess is that if there are more than (say) 20 pax on board there's a better than evens chance that at least one phone is active throughout the flight (whether by accident or design). More than 100 pax and it's practically a certainty. Since we do not observe any serious problems that have arisen as a result, this would indicate that such problems are very rare, if not impossible.

Airlines (now that they can make additional revenue from it) are offering the ability to use your mobile in flight. This is done by siting a 'pico-cell' on board, allowing the phones to operate at their lowest power setting. Someday this pico-cell will fail, at which point all the active phones will automatically boost their signal to the max in a futile attempt to contact the nearest base station 10 kms below them. This will be an excellent test of the aircraft's susceptibility to EM interference. My guess is that nothing will happen (see above) - what's your guess (and would you want to be on board when this 'experiment' takes place)?

folks look crazy talking to themselves on cells, I believe they should not be used, simply because of POSSIBLE RF interference. we don't know the frequencies emited by the huge variety, of phones and how they correalate with avionics/sytems freq's... due to anectdoatal reports I think they should be TURNED OFF...I trust when airline pilots say they've experienced RF interference. by the time we prove the point i think there'll be a smoking hole in the ground and people will say why did they allow cell phones aboard. Next time a pax just HAS to talk to his or her friend/ girlfriend/ boyfriend/mom aunt think of that baby in coach who can't uses a cell phone....ending up in that burning hole...I'm a pilot not an airline pilot... and I as a occasional pax I don't like it... playing statistics... that is, but i've learned although individuals are smart, people are stupid and selfish...keep the :mad: ing phone OFF plz:=

Journo123:

To cut to the chase, and to point you (hopefully) in the right direction, without swaying you one way or the other, there's a couple of things you should know:

(i) Mobile phones being allowed on aircraft isn't a contradiction of the safety regulations. That's because of the advances in 'picocell' technology which effectively allows the phone to operate in the cabin on reduced power - thereby cutting the risk of interference. I have no idea what would happen if the picocell malfunctions, however.

(ii) The truth is that the jury is still out on the level of risk to flights. While there's no record (as far as I know) of an accident attributed to passenger electronic devices, it's certainly true that mobile phones create interference - which at the very least is irritating. And studies (by the UK CAA for example) on the effects phones have on avionics have demonstrated that there is enough doubt to warrant erring on the safe side - ergo, you can't use your phone.

Perhaps the most interesting evidence I've come across is the anecdotal stuff reported to NASA's Aviation Safety Reporting System (you can download a whole batch of the most recent electronic device interference incidents from the website - asrs.arc.nasa.gov). Some of these reports are certainly food for thought for anyone who wonders whether there's any real reason for concern.

A test
 

Yes, strictly a test, to see what happens.
Scene one.
At the end of the runway at KLAS, in my private aeroplane.
The aeroplane has all King Gold Crown AIRLINE standard radios, about twenty five years old.
All six passengers use their mobile phones at once.
Result?
Absolutely nothing.
NO interferrance on the comm or nav radios.
None...zip.
Once airbourne, all use the mobile phones once again, all at once.
Result?
Same as above.
Nada.
This mobile phone interferrance nonsense is a bunch of cr@p.
Of course, Airboos aircraft may well be another story...and one might ask, why?
Can't Airboos design their aircraft to proper standards?
Answers on a postcard.:rolleyes:

See this FCC link for the mainreason they were banned - COMMERCIAL!
http://www.fcc.gov/cgb/consumerfacts/cellonplanes.pdf
Extract
"FCC rules currently ban cell phone use after a plane has taken off because of potential interference to cellular phone networks on the ground.In addition, the Federal Aviation Administration (FAA) has rules prohibiting in-flight cell phone use because of potential interference to navigation and aircraft systems."
At least the FCC is honest!
I remember years ago Noel Edmonds (UK TV Personality) flew his heli from Nth Scotland to Southern England while BBC TV Tomorrow's World tracked him by the cell activity. The simple fact is that when airborne, the phone locks on to more than one or two stations which can (or at least in earlier days could ) lock up precious lines.
Nowadays, I reckon the main safety hazard is n the ground, taxying, phones all coming alive, ATC spot a conflict, call "XYZ123 hold burpp burpp... "
Result maybe an accident.

A test
 

Further to 411A's non scientific but otherwise valid test. I've been in a Challenger with at least 3 phones in use. Miracle - we're still alive, I think!
I hav also received calls from the Flt Deck - before we got Satfone fitted
There's loads of anecdotal "evidence" but no hard facts
Simply boils down to cost. It's easier to ban than test - until now, when theres money to be made!

So 411A how do you explain the following.

Flying around in my 172 with my cell phone inadvertantly left switched on in my flight bag.

Everytime the phone searched for a network,changed networks,and actually rang it interfered with the VHF radios. If it can interfere between 118 MHz and 135 MHz I am sure it will do the same just below 118MHz on the ILS frequencies....? Who knows what the consequences are.........

Now back in the real world we all know that modern aircraft have suppressed wiring / systems etc but not ALL aircraft carrying pax / freight etc are modern......

As for the passenger disruption issue, dont even go there !!!

If the airlines are so keen to offer onboard cell phone usage why don't they convert a toilet or galley space into a small room ( as per Malaysian Airlines where I think it was a room with a fax etc installed ) to allow pax to make / recieve that oh so important call......

If the legal use of cell phones come in on aircraft I would be interested to see the statistics for the incidences of air rage......I know for one I will not be too happy being woken up in the middle of the night by someones irritating cell phone ring followed by the inevitable " I'm on the plane !":mad:

Quite simple, anartificialhorizon, the radios in your C172 are (ah, how do I put this nicely) lets just say....OF POOR QUALITY.

'Tis a wonder they work at all.
Hey, I tried to be nice.:E

Airline standard TSO quality avionics are a different kettle of fish altogether.
Yes, even twenty five year old ones.:D

Gee, I wonder why....

And I did'nt know that airline standard equipment was of better quality ! Thanks for the heads up :ok:

The point is if a mobile phone can interfere on a wavelength totally different to what it operates on means it can interfere............Despite suppressors etc atmospheric conditions can do some strange things and therefore while I am close to the ground i would prefer for these things to be off. If you are going to let people use them they will and will keep them on for descent regardless of what the cabin crew say........

For gawds sake we don't even fully know the health implications of the use of mobile phones so do we trust the fact that they are 100% safe to use on aeroplanes..................?:eek:

As someone who has been involved in aircraft certification I cannot help but cringe at the 411a test.
It is not what we call a "statistically significant" test. Unfortunately this guy falls into the "unconcious incompetent" category when it comes to detailed engineering issues. Often recognised species who make bold black and white statements which contrdict industry accepted standards.
"Hey I flew under a CB anvil once and nothing happened....whats all this trash about it being dangerous" Very good ...highly scientific thanks for your input should be the stock reply to such people.
There are more people out there who have had radio interference from ONE mobile phone than those who have not.
The fact is aircraft certification demands rigourous testing at the extreme end of the spectrum.
I cannot give all the details here as I was involved with an "interested party" at the time but there has been at least one occasion where mobile phones were STRONGLY SUSPECTED to have been a primary factor in a serious accident.
Basic outline
Eastern airport ....very bad weather....aircraft went around and Captain made the standard early call to punters telling them what was going on, don't worry, and that they were diverting to XYZ airport.
Lots of punters ALL AT THE SAME TIME (ie extreme case) made calls to their pick ups , families business etc (all traced and time marked during the accident investigation) telling them they would be late, needed taxis ordering from new airport etc.
It is true that it was never conclusively proven that this spike in mobile use was the cause of the aircraft's significant heading deviation (and that is how interested parties probably managed to keep it out of the accident report). More than 60 mobile phones were found switched on all over the mountain side (a lot more had the batteries dettached but were registered as making calls prior to impact).
A rather lighter incident was the guy on a hot Summers day (above flashpoint) at the petrol station was filling up his car with mobile phone (which was in the pocket nearest the filler point) when someone rang him.
This ignited the fuel vapours and seriously burnt his gonads....checkout the "no mobile phone use" signs at garages these days.
But hey no doubt someone has had cigarette whilst filling up...so it must be safe.

I'd be keen to know how you quantify this remark.

Furthermore, if the American Petroleum Institute after numerous tests concludes cellphones are perfectly safe at gas stations they'll be guilty of heresy eh?

I'm surprised some of you chaps manage it out the front door.

Gentleman

Plenty of work has been done on this

http://www.caa.co.uk/docs/33/CAPAP2003_03.PDF

Mobile phones are quite capable of creating havoc on the flight deck. Operaters that are starting to introduce mobile phones on board are using Pico cells which preclude phones having to boost the signal too find a cell. Although given the quality of some of the screening I see on aircraft I am not entirely confident this will help. :eek:

Widebodyeng,

I have tell you that the FCC is known to emit politically based rules without sound technical basis, and the sentence you highlighted, is so meaningless that will make laugh any telecommunication engineer.

Moreover, a mobile phone cannot 'lock' to more than one station at time, but even if it did, it would not 'take up precious lines'. Not even in earlier days. A line (a whole channel in analog systems, portion of domain in case of digital) is taken up only when a cellphone makes a call.

Note that I'm not defending the use of cellphones on airplanes (at least liners) but merely explaining you why mobile handset cannot do harm to the network no matter the topology they are in relation to multiple towers.

Telecommunications happens to be a science well developed, funded and researched just like aviation so even if it doesn't have an authoritive answer on the matter of interfercences to avionics, please believe me when I say that such a silly, easily solvable problem, if ever existed, is no more today.

Absolutely true. Only a cellphone that has been seriously tampered with would produce sparks able to ignite gasoline vapours (if there were - higly unlikey as well).

The signs that you see are the product of our litigious and hiper-protective society, were too often safety decisions are made not by scientists and engineers, but by general managers with totally different goals. It does cost nothing to prohibit cellphones while refuelleing and gives to the publice the false feeling you're looking after them.

At the same time they may not tell you that the same station thanks (hipotetically) are not sealed/inspected carefully and releasing toxic substances in the soil, but the general public would never notice that, while the ignition video is rapidly circulated to become another urban legend, so they feel they must protect their .sses first.

Filling Stations and Cellphones.
 

Urban myth alert: so, if a cellphone (max TX power 500mW) can ignite petrol vapour, how come the cellular base station (TX power 50W) whose antennae are housed in the "tombstone" sign on the forecourt doesn't ignite them?
Shell filling stations in the UK frequently house T-mobile base stations. Also, there is a 150W 3G O2 station on the pavement (3 metres from the pumps) beside another I know of.
Back to the subject: much is made of the "dit-a-dit-a-dit" noises heard in audio frequency equipment from GSM phones -- this does not mean there is high-level RF interference.
I find it hard to believe that a cellphone operating on a maximum of 500mW TX power at 900MHz or above would interfere with airband equipment operating at a much LOWER frequency (VHF airband). Harmonic interference is produced on upward multiples of the fundamental frequency in use. I regularly use both airband and amateur radio equipment in close proximity to cellphones (OK, OK, I'm on the ground ;-) and have seen no cross-interference.

Actually, the maximum transmitting power for GSM on 900 MHz band is 2 W, reduced to 1W for the 1.8 GHz band.
A bit of basic info, easy to understand for everyone about the frequencies used in europe is given at:
http://www.techmind.org/gsm/

I used my laptop wifi on a luftansa flight the other day. We didn't crash. There was a sign saying I could. Do you think they re-wired the whole aeroplane when they put in the HOT SPOT tx/rx?

FE OK, but wi-fi is much less power, just 100 mW. That's why Boeing has invented Conexions and Lufthansa (and few others) sells it. I don't think they rewired anything because is so evident that wi-fi does cause no pro blem whatsoever.
Cellphones are much more powerful so there is still some concern and resistence.

I was told that they were banned for two reasons, one already discussed their effect on the aircraft, but also because they are not licensed for such use by the governments/service providers because they cause havoc with the cellular principle on the ground.

When you move from one cell to another, either on foot or in a car, you are "handed over" to the next cell so that when anyone rings you the system knows where you are and which cell should try and contact you.

If you are at 35,000' and doing 500mph then you are in range of lots of cells because of you altitude, and the cells cannot cope and the amount of switching cells causes havoc in the system. Perhaps that is no longer true, but that is what I was told in the early days of mobile phones.

Hi Seat1APlease,

Had you took the time to read the whole thread (this means one comes trying to learn something beside his teching of his own), you would have learn that is totally unproven, that now or ever, the cellphone network can get trouble from fast moving handsets.

When you operate a wireless infrastructure, is not like you can base yourself on regolamentation to prevent trouble, because that alone does not prevent people to do, purposely or not, the widest range on things and tricks on your network. Like turnining on and off thousands of simulated cellphones at the same time. Or making appear a cloned phone in different parts of the network simultaneously. Or a plethora of violations on the protocol in the hope of getting free service or simply vandalism.

Networks are designed to cope with all that. The flying handsent, believe me, is the last of their concerns.

Selphin & El !
Re "There are more people out there who have had radio interference from ONE mobile phone than those who have not".
How do I quantify it...more than 50% of pilots (ie the majority) have had a situation where one mobile left on by a passenger has caused interference (by which I mean unwanted / distracting noise) heard through the headset. Last happened to me on Thursday at about 110 knots just before rotate. Really don't need it.
Last year one of our aircraft had a high speed abort because a mobile phone in the hold rang and the signal produced a baggage fire warning.
Checkout ARINC and Mike's links and you might learn something.
This is a serious safety issue which has cost people their lives. As I said the petrol station was a bit of light hearted (if slightly sadistic off subject) humour...but as you seem to get so excited about it here are the facts.
It is off subject because this 1999 explosion had nothing to do with interference.
The guy fumbled around in his pocket to answer it... managed to dislodge the battery which shorted on some coins...this was the spark which caused vapour ignition.
In August that year David Rudd (senior Motorola bod) confirmed that a dislodged battery (coupled with a short between contacts) would cause a spark capable of vapour ignition and this is where all the gas station warnings came from.
There are hundreds of thousands of gas stations and millions of mobiles in the world and most (if not all) mobile phone manufacturers issue guidance with every one sold not to have your mobile switched on when refuelling.
FEHoppy - Non transmitting devices are OK this thread is about mobile use.

I hear you RMC.

About cellphones and gas stations - one can still dislodge the battery even with the phone off - actually to make a short with coins it has to be in a pocket or bag but never when kept in hand - do you think the prohibition is intelligent ?

and, FE Hoppy was talking about laptops with WI-FI that very much transmits, allowed and encouraged by Boeing and innovative airlines:
http://www.connexionbyboeing.com/

Are you ok with that ? Even if 50 passengers were using it at the same time ?

Hey El !
True about the battery vs phone status...I think what they are saying is if its not on you won't answer it/ make a call/ drop it and accidentally dislodge the battery (covering their ass without actually saying leave your mobile at home).
Regarding WI-FI i have a wife and a HI-FI...is this a combination of the two. In other words I have do not have enough theoretical knowledge (and no empirical evidence whatsoever) about WI-FI and would appreciate some enlightenment.
RMC