Any PROOF of Mobile Phone "interference"?

[Ray Darr]

...a fire warning triggered by a mobile phone left on in the aft hold....

Can anyone not speculate, but post FACTUAL accounts of mobile phones causing anomaly's? After many years (well over two decades) of flying everything from conventional to the latest whiz-bang-more-advanced-than-the-Space-Shuttle machines, I have YET to experience any alarm / warning / shut-down / pressurization / "it's not working...!" / "Huh, why's it doing that??" / etc etc, caused by ANY mobile phone.

Think about it. How many countless flights operate - daily - where the passengers stuff their transmitting phones innocently into the overheads, and on short finals there is an orchestra of beeps, bleeps, dingles and dongles as they all acquire their signals and receive incoming text messages, calls, etc? YOU'VE heard them! And this happens DAILY, ALL OVER the world. Yet nothing has fallen out of the sky.

The most annoyances I have ever encountered with mobiles is when someone, ATC, crew, whoever, leaves their phones near the hand-mics and when an incoming signal just happens to coincide with them transmitting, we all hear an annoying "buza-dah-dah-dahzzz" (OK you make the sound look doable in text...). Oh, and same thing goes when wearing headsets when someone beside you gets a call. That also makes faint buzza-dah"...etc etc.
But aircraft systems? Hardly.

Any "real life" - FIRST HAND ACCOUNT - stories out there?? Discount the ones from "friends of co-workers aunts that watched a special on the Beeb a few years back who then wrote a letter-to-the-editor on Roger Bacon's page in Flight Int'l" (bless their souls, just the same). ...and skip the "famous" 747 "depressurizing" story from a few years back, unless that was PROVEN caused by a mobile. Other stories, if they are first-hand accounts, would be entertained, though!

By the way...the background on banning mobile phones goes back to the early days when analogue phones would automatically boost their signals when the towers reception was fading. Being airborne, these phones locked on to many cell-towers at the same time, and caused headaches (signal loss / outages) for users...and the mobile phone companies got rather annoyed at this, so they asked the FCC in the US (where these issues were in the majority, since the cellular-phone system was primarily US-based back then). The FCC approached the FAA, and the FAA placed a blanket "thall shalt not useth thy mobile phone whilst in thy air!"...and the "rule" caught on world-wide.

Some carriers tell you to shut your phones off when boarding right through to engine shut-down on the other end. Others allow the use on the ground - even encourage the use after landing - whilst taxiing - in the case of one US carrier. It's not a consistent situation, and it's brought on by out-of-date "rules".

ALSO - IF CELLULAR PHONES WERE UNSAFE, WHY IS THERE A PUSH TO EQUIP AIRCRAFT WITH CELL-TRANSMITTERS TO ALLOW PASSENGERS TO USE THEIR EXACT SAME "UNSAFE" PHONES AT ALTITUDE?! (yes, I know with a transmitter / receiver on-board, the phone output is very low...but still.)

So, you know my views. Is there any first-hand accounts of mobile-phones GENUINELY causing anomalies, anyone?

...And PLEASE skip the debate of phone usage on aircraft as being a no-no from the view of everyone having to put up with the "YADA YADA YADA" factor. Lets keep this strictly on the debate regarding phone/system interference. Thanks.

Interference?? ...a load of bunk, methinks.

Cheers,
Ray Darr

[Voeni]

Good post, Ray...

Although not flying for decades, I have yet to experience or hear/read about an incident caused by mobile phones. All nonsens, me thinks...

BTW: I like that "buza-dah-dah-dahzzz"... pretty close!

[vapilot2004]

A couple of years ago, I witnessed one of our MX guys use his ordinary Nextel phone to repeatedly trigger a BSCU fault from the nosewheel area of an A320. It was discovered by accident during troubleshooting an unrelated system fault and was believed to be the result of the mobiles EMF entering VIA a position sensor connection where poor lead dress had existed.

Try this at home:
Have your FO take a walk outside (preferably while the AC is on the ground) and use his/her mobile below the port-side wingtip (flux valve) while watching the Compass SYN light on a 737 Classic - works every time with the Honeywell-gate equipped AC.

I have also seen an Omega Nav CDU go wacky from an o-l-d Motorola brick phone. (ok, I'm dating myself).

Aside from the correctable BSCU system defect, all my examples are from pre-1990s aircraft. Newer systems are supposed to have more robust spurious signal rejection. None of the above resulted from passenger cabin phone use.

I think the most dangerous issue with mobile use while aboard must surely be the cacophony of passenger’s blah-blah-blah during a flight. :eek:

[Mad (Flt) Scientist]

Did not early service days in the dash8/Q400, especially with SAS, not have multiple false baggage fire warnings that were blamed on/traced to cellphone interference from phones in packed baggage?

[Denti]

A few years back we had an enconter that might have been caused by a mobilephone. While holding at pretty low altitude (3000GND or something) we noticed the vibration indication on one engine moving up to 5 without any actual vibration noticed from anyone of the crew. Captain made an announcement about checking for mobiles, one was found from a pax and switched off, after that the indication returned to normal (a tad below 1). All that on a 733. Never had that after or before although i am sure many more mobilephones had been on on other flights (including some on the flightdeck).

[Thermal Image]

You may (or may not) have seen this report / study by the UK CAA titled:

Interference Levels In Aircraft at Radio Frequencies used by Portable Telephones, found here:
http://www.caa.co.uk/docs/389/srg_acp_00021-01-030303.pdf

A 1 page summary of that study (amongst other things) is found here:
http://www.casa.gov.au/fsa/2003/sep/33.pdf

The short answer is, yes, mobile phone emissions cause intereference / anomalies.

[Rainboe]

RD, you are convincing yourself that mobile phones are not a problem because nobody can prove to you that they can cause a problem. You are aproaching this the wrong way. Until you can prove mobile phones are NOT a problem, you should accept that the possibility is there. Until it can be shown that a mobile phone can be anywhere in a cabin and not cause a problem, we should not be pushing to relax the rules. I do not want to be the statistic that may show they can be a problem while we try and sort this problem out!

I also do not want to be subjected to a cacophany of telephone conversations on aeroplanes that go on all through the night when people can't sleep, and stop those around them. this whole thing could be a social disaster, and I'm afraid unless aeroplanes can fit phone booths, I certainly don't want to be an unwilling listener to multiple "I'M ON THE PLANE!......somewhere over Sudan!......landing in about 5 hours......WHAT? SHE DIDN'T!......" Spare us please.

[B737NG]

Motorola 1000 old type GSM, 8 Watt power. A few years ago: Rhein lost our Transponder signal when we passed thru FL 280 in the desend. We had the phone shortly on and then immidiatly off again. It caused a MD11 climbing as well. So trust it, a mobile has an affect. If we would know exactly what effect then the mobile phone company´s would love to eliminate that. Can you immagine how many roaming charges they could make in the air? Keep it off and there is a good reason for it. Accept the fact and don´t debate.

Fly safe and land happy

NG

[The Real Slim Shady]

Not just mobiles!

Row 11 on the F100: anyone using a laptop could generate spurious alerts on the MFDUs.

[Ray Darr]

I hope this is informative for everyone. It is for me.

If you can cite specific documented reports (like some of you already have) it would be great for those in Flight Safety, etc, to then use those reports to change or re-enforece procedures, etc.

Keep them coming, guys. It's appreciated.

~ Ray Darr

[klink]

Recently "we" had the autopilots disconnecting multiple times and all other flight director related "funny things" during flight in a 737 NG.
Announcement made; peeps in the cabin checked their phones; one had his "popular scandinavian brand" phone in Flight Mode.
Thing switched off; everything back to normal.
Currently under investigation.
Its better to be safe than sorry.
And anyway; if you leave on your mobile in flight you can disrupt the networks since you would connect to multiple cells.
Just put the bloody things on and give yourself some time off.:ok:

[ferrydude]

http://www.ainonline.com/Issues/05_06/05_06_cellphones_1.htm

[Clarence Oveur]

Consider this,

The electromagnetic energy a mobile phone is capable of generating, exceeds the certification levels of present day avionics.

[south coast]

so, if they do affect the planes instruments, why do some carriers say that phones should be switched off at different times...some say when doors are closed, others when engines are running, others when in the terminal...

not very consistant.

[klink]

...because they give in to what the customer demands.
They want to be nice and let you do your important stff as long as possible, without risking an immediate danger.

[standardbrief]

flying an atr72 on approach heard that annoying sound but the atpcs autofeather system arm light also started flickering. hard to know if that was cause?

[bushbolox]

I think Burzz dah dah burrrrrzzz dah dah burz etc is closer.

[klink]

how about biddibip-biddibip-biddibip

[chevvron]

Report in UK GASIL 04/2003.
A 'recently manufactured' aircraft fitted with a KAP 140 autopilot was collected from maintenance, and when the pilot dialled in a left turn, he found the bank angle and rate of turn were much less than expected; he then tried a right turn, and found the aircraft rolled rapidly to the right, well past the usual angle of bank.
A mobile phone in the baggage hold was found to be switched on, and when it was switched off, the A/P response became normal.
Not conclusive, but it's not the sort of thing you want to discover if departing in IMC and engaging A/P soon after takeoff.

[Oh that's super!]

Have a look at this link and download the complete report from here:

http://www.atsb.gov.au/publications/investigation_reports/2004/AAIR/aair200402797.aspx

While this document is not about interference from mobile phones, it mentions cases of Trimble GPS and mobile phone interference.

[overstress]

How about an A320 during SRS phase of take-off dropping into heading+v/s, coincident with the bip-dibber-dib-dibber-dip noise? Traced to the management bod sitting on the J/S! :D

[ionagh]

As an RF and EMC engineer I can tell you that there is a definitive answer to the question:

Yes but.......

The interference depends on three critical factors, the RF power used, the frequency band used and the type of modulation. All these three vary in different countries.

Cellphones can be 450MHz, 800MHz, 900MHz, 1800MHz etc... Interference is VERY frequency selective and the airborne systems MAY only be susceptible to one of those bands.

Cellphones can also use different modulation, on-off pulse types like GSM, wideband like spreadspectrum or fixed carrier. Interference will be more noticeable from on-off pulsed types like GSM.

Given also that the RF power used is controlled by the system and can vary from almost nothing to 'beyond the certified limit' of the airborne systems you have a huge range of possible scenarios. Most people will quite rightly be able to say that 'their phone never caused a problem'.

I have instruments mis-read, computer systems crash, volatile memories scrambled, other radio receivers go 'deaf' etc....

Then add the 'invisible' effects. Such as the RF causes the computer system to crash but the computer uses as watchdog program that re-boots the system after any such crash. No visible sign of interference but the computer has effectively gone awol for a percentage of the time.

So to complete the answer:

Yes BUT only a small percentage will.
How good is your risk management :E

[Dan Winterland]

On an A320, ECAM messagethat a MLA computer had failed. Being a non dispatch item we were keen to fix it. Nothng worked until a suspicion led us to make a PA to ask the pax to make sure their phones were switched off. Problem went away about 15 seconds later.

[ShyTorque]

Yes Ray, mobile phones certainly do affect some aircraft. As well as interfering with the intercom/radios, our aircraft's aft baggage bay smoke warning comes on in flight if a live phone is left in there. As there is no fire extinguisher in the baggage bay (and the fuel tanks sit below it) the emergency checklist says it's a land as soon as possible, which could mean in a field in our case. Especially not funny if IFR. It's specifically emphasised in our pax brief for that reason.
BTW, for more info, there's been at least other three threads on this subject within the last year or so. Search for "mobile phone". :ok:

[petitfromage]

In A343 Ive seen the the Capts mobile cause random 'flip-flopping' of PFD & ND (on ground before push back)

Have also seen/heard ground engineers radio causing the fancy bullet proof door to unlock when he pressed to transmit!

[aw8565]

My groundschool instructor told me about a friend of his in his new Cirrus that had a switched on mobile in the centre armrest/cubbyhole (like a Ford Mondeo I assume.) Apparently the interference gets stronger the further away you get from the source and the phone caused a problem when it came to disconnect the autopilot.

I think it had caused real damage to the system and a CB or two had to be pulled in order to disengage it. Not exactly first hand as stipulated but I have no reason to doubt its authenticity.

[ampk]

A big fellow Pat when I was in Botswana a few years ago had his fisrt solo flight on the S333 (269D) helicopter.
Very good reason to belive his ex or someone called him on his mobile( it was investigated but no evidence-pre paid phone?) during the helicopter being refueled,

the fuel cap was found on but not rotated and locked.

Result result was a short firey fatal flight.( 7 day fight for life)

Something I never want to see again- is a phone call that important leave em off when ur working.
RIP PAT P.


Cant get any more interFEERing than interFEERing with the CAPTIAN

[reDevil05]

None of you watch Mythbusters on Discovery?
There's an episode where they test the cell phone myth on airplanes. Quite an interesting episode I must say.
I'd love to post the results of their findings, but it gets way too technical for me. My suggestion, watch it !
It's episode 12 of season 3, in case you are interested.

Enjoy !!

[Fragman88]

744 short finals for Singapore, F/O flying, me just gone to PA to secure the cabin for Landing. I hear dialing beeps through the headset, a bit of connecting squirt, and all the RHS nav instruments go AWOL, with the associated whistles, bells, flashers, autopilot dropout etc. That was real enough for me. As`others have said, could depend on the phone itself, the position, and even the surroundings---the nice titanium laptop case or metal briefcase might act as a reflector to intensify or focus the signal.
CAA studies seem to conclude possible problem. I concur, apart from which---make the most of a few hours with the pesky thing off!:\

[Hoover Pilot]

A pretty convincing case for me.

Captains Navigation Display suddenly started oscillating as if the aircraft were rapidly turning left 30deg then right 30deg. PA made to passengers resulted in one passenger discovering that this phone had been accidently left on. After switching phone off - problem immeadiately disappeard.

Same symptoms on other flights - same PA made - same immeadiate miraculous fix experienced - though on these occassions no pax actually confessed. I am pretty convinced though.

HP

[ferrydude]

http://www.avionicsmagazine.com/cgi/av/show_mag.cgi?pub=av&mon=0606&file=editorsnote.htm

[MAS Guy]

Usually radio interference, and sometimes autopilot disconected

[ferrydude]

Actually Ray Darr, your post regarding the background of how the mobile phone ban came about is not correct. FAA does not specifically ban the use of mobile phones, FCC does, nor did they approach FAA and request a ban on such. In fact, FCC is now ready to remove the restriction. FAA has always maintained that no electronic device can be used onboard until it has been determined that it will not cause adverse side effects, (interference). This determination is left up to the aircraft operator(s), hence the different policies regarding when and if devices can be used by the various air carriers.There is quite a bit of anecdotal evidence pointing strongly to mobile phones AND other portable electronic devices causing interference, studies are ongoing. You might find this of interest.
http://www.avionicsmagazine.com/cgi/av/show_mag.cgi?pub=av&mon=0606&file=qa.htm

[rabidpangolin]

Wonder how long it is going to take before "they" can quantify these little headaches. Luckily for me, the planes I fly are so old that the interference is to the phone and not the aircraft. Good luck to you chaps in your TV-guided missiles!:}

Cheers!:ok:

Mind the tail!

[reDevil05]

Luckily for me, the planes I fly are so old that the interference is to the phone and not the aircraft.


Does your plane not use any Nav aids?
I've heard of VOR's going nuts due to mobile phones.