Mobile Phones in flight - again (merged)

[Taildragger]

I watched a Documentary on TV the other night, and it commented on the moment when Tony Blair was told about
Dr. Kelly's death. It was in flight on approach to the detination (Can't remember where - Africa, I think) and they showed the cabin of the aircraft when many of the journalists hit their mobiles immediately to pass the story to their papers back in London.
As I recall, this was a BA Charter, and not Rafair.
Can I assume that the rules still apply on the PM's Charter, or were special arrangements made for them.?? It would still be potentially dangerous would it not.??

[Sleeve Wing]

Somebody put me straight.
If they're using SATFONES, is that OK ?

Sleeve. :confused:

[FE Hoppy]

I hate to open this can of worms again, but apart from two false cargo smoke indications on one of the small turboprop twins what evidence is there for banning the use of mobile phones due to aircraft problems??
Talking to my mates at Nokia they say the problem is with the base stations going mad cause the phone connects to loads of them.

[Captain Stable]

Taildragger:- No, spcial rules do not apply on the PM's flight. The journos may have been using aircraft phones.

Sleeve Wing:- No, satphones are not OK.

FE Hoppy:- The CAA inform us they have a significant body of evidence. Available to be viewed. The link was posted on PPRuNe within the last couple of months - try doing a search. Your friends at Nokia are also correct - they do confuse base stations.

[M.85]

Used to phone the hotel guys to pick me up right about the outer marker..worked perfectly..by the time i landed the van would be there waiting for me..

;)

M.85

[swish266]

Lufthansa Before start Checklist bottom line: "Mobile phones" - "Off".
Guess they don't leave anything to chance.

[Dr Illitout]

I personaly couldn't think of anything worse than sitting next to somebody shouting "HELLO I'M ON THE PHONE, ON A PLANE!!!". I do hope that the blanket ban on mobiles on planes stays!.

[natus82]

Hello there,

I'm a final year aeronautics degree student doing my dissertation on RFI and its effects on aircraft systems and instrumentation. I would very much appreciate any information or advice anyone has to give me with regards to this subject,

Thanks

Andy :suspect:

[ILS 119.5]

Heard lots about this but have not seen any conclusive proof that mobile phones affect computer systems. I once took a mobile phone call whilst in a petrol forecourt to the horror of another driver filling up her car. She protested so I walked 3 metres to the outside of the gargae perimeter. No problem then. Although we are not allowed to use mobiles on the flight deck in flight they are used on the ground. If mobiles affect computers then why are they used in the vicinity of any computers. Does anyone have any hard evidence to justify the non use of mobile phones on aircraft or which may affect computers.

[BOAC]

A F/E told me that the give-away on a 747-200 was that the pressurisation control valve indicator on his panel flickered when a mobile phone was in use (and presumably the pressurisation!)

[FOZ]

The issue of the mobile phones interefering with electronics I suggest possibly dates back to the analogue system. The power output of the phone was higher - up to 4 watts for "portable" phones which were in fact car phones on a battery pack. The handheld ones operated up to 2 watts, compared to the current digital mobiles on about 0.25 watts.

On the petrol station issue, and perhaps relevant here, mobiles (analogue as far as I am aware) had been proven to affect on very rare occasions the fuel pump electronics, allegedly causing false readings for the amount of fuel dispensed.

There have been many scare stories about mobiles causing fires at petrol stations, but I believe these all to be false. Afterall, the constant sparking in an alternator at the brushes, or a spark in a solenoid or starter on starting an engine are far more likely causes of vapour ignition - plus turbo temperatures / catalyst temperatures on running vehicles are higher than the ignition point of petrol vapour. Furthermore, the stories have just been stories, with no further information. The major fuel company we use has no record of fuel fires specifically caused by mobile phones.

At "point blank" range, mobiles can cause interference as demonstrated by holding an operating mobile phone by an amplified PC speaker, but the interference disappears at a short distance.

There is one other issue in this-in the UK we have a high density of cell masts. Handover from one to the next is very much dictated by the cell you are on, broadcasting the details of the cells that surround it and that it is prepared to hand over to. This is optimised for use at ground level, and according to one of the big 4 networks, would not be able to support mobiles jumping across several cells at once - even if the signal were able to penetrate the aluminium fuselage and that the cell sites transmit generally on a horizontal plane.

Finally, it is known that phones are left on unintentionally on many flights!

[bookworm]

The CAA research seems to be two-pronged:

Interference Levels In Aircraft at Radio Frequencies used by Portable Telephones (http://www.caa.co.uk/docs/50/Gsm_intf.pdf)
looks at the electric field strength in various parts of aircraft caused by a mobile phone in other parts. The highest field strength observed was about 4.5 V/m in the flight deck when a 2W 900 MHz phone was used in the forward cabin of a 737. This would exceed the limits in the certification standard of equipment before 1989, but not more recent equipment. Avionics bay fields reached about 1 V/m.

Effects of Interference from Cellular Telephones on Aircraft Avionic Equipment (http://www.caa.co.uk/docs/33/CAPAP2003_03.PDF)
reports on experiments in which a number of pieces of avionics certified to the older standards were subjected to field strengths of 30 and 50 V/m, equivalent to putting a mobile phone about a foot from the equipment. Unsurprisingly, they found the equipment misbehaved from time to time.

I have to say that this doesn't strike me as a significant body of evidence indicating a problem, but nor is it an all-clear for mobile phones.

[moo]

actually use mine in the cockpit/mec/all over 747-400s every day when in for maintenance. have done for 7 years. never seen any abnormal happenings.

[balloo153]

I am flying as FO on the B737 NG and during a night low visibility approach we always heard the sound a mobile phone makes when it tries to find a net, you know that didididadada in our phones. It was really harassing, probably some kind of passenger trying to contact someone. Shortly before the self confidence test our autopilots disengaged. We made a go-around, made an announcment to please switch off all electronic equipment and gave it another try. It went all straight - like in the books.
Well in the end we were not shure what made the autopilots disengage, and I really can't tell. But I think maybe the cellular phone had something to do with it. But that is my personal opinion - nothing official.

[Justbelowcap]

Lets look at it another way. How many flights do think actually operate without mobile phones switched on? Possibly every flight on a decent sized aircraft will have at least one or two phones switched on. Every pilot who has flown in the last two years can probably give examples of phones being on in the cockpit let alone in the cabin. My airline has a 120 different parameters constantly monitored on every flight, about 2 a year are MAYBE attributed to mobile phones. Name one working pilot who would return to stand if a passenger said he had left his mobile on in his hold luggage. Lets be realistic it just isn't a problem worth worrying about. Now lets talk about non-precison approaches (28 ZRH-no excuse in a wealthy country), current fuel levels (ac arriving with less than 1.5 times reserve fuel), the use of native language instead of English, TCAS response being incorectly taught in some airlines (DHL victim), hold over time calculation not calculated correctly (i:e stopping when the precipitation stops..this is taught by many airlines but is INCORRECT), fatigue, pilots who aren't given crew food and suffer low blood sugar, commands with less than 5000hrs,etc etc. The list is endless. Mobile phones aren't worth worrying about compared to the real safety issues.

[bookworm]

There is a very detailed CAA Technical Report from last year that lists a lot of alarming faults that a mobile ‘phone has been proven to cause...

That's a little misleading. The study subjected a number of pieces of avionics (all certified to standards superseded 15 years ago) to an electric field that would be the equivalent of a mobile phone held about 12 inches from the avionics. Since the field falls off with distance squared (subject to certain questionable assumptions), one wouldn't expect a mobile phone in the cabin to create a field of anything like that much.

[EddieHeli]

Hi,
I experienced a mobile phone incident during my first Helicopter Flight Test for my PPL (H) in an R22.
The examiner answered his mobile whilst I was flying, and when he was finished with the call he placed it down in front of his seat.
He used this opportunity to pull various circuit breakers thus testing my responses to various warning lights coming on and off.
(I passed by the way).
I am now always suspicious of examiners placing things in front of their seats, and make a point of ensuring their mobiles are off before the flight.
I notice when I have left my mobile on by the dit dit dit in the headphones, but can't say if any of the instruments have been affected.

:D

[Speed of Sound]

There is .....

NO proven evidence for Mobile phone interference with aircraft systems.

The reason they are banned from use in the cabin is that, as we all know, they have to 'talk' to the host cell every so often. As an aircraft ascends the phone puts out a higher and higher powered signal as it desperately tries to locate the increasingly distant base. A combination of this high power and the direction in which the signal arrives at the masts can cause the cellphone system to crash.

An aircraft that had avionics susceptible to mobile phone interference from the cabin would never be certified.

SoS

[john_tullamarine]

Strange, though, that Industry electronics/avionics publications maintain that the problem is complex and that the jury is still well and truly out on the assessment.

The comments re certification may well be reasonable in an EMI-hardened military system but the question to hand relates more to the lower capability civil standards ? I suggest that there is more than enough anecdotal, and ample controlled experimental, data to suggest that the answer is not so simple as some might prefer ...

[Galdri]

Mobile phones HAVE effect on the 737-300/400!

In a very unofficial 'test' done by the guy who checked me out on the 737 (in CAVOK conditions, I hasten to add!), he found out that if he made a phonecall, or received a phonecall, on the ILS the autopilots WILL disengage.

He performed his unofficial 'test' after hearing the 'dit dit dit' mobile sound in his headset. At the time they were flying CAT2 ILS into Copenhagen and both autopilots disengaged during the mobile sound. After landing he found out from the FA's, that one of the pax on bussness class had used his mobile during the approach.

So, receiving or making a phone call can/will disconnect autopilots.

[REM]

I have seen the outflow valve needles move (and presumably the valves) on a 747-300 when a Customer Service Officer used their radio on the flight deck.
I have also had a pressurisation problem on descent when coincidently, a F/A suspected a passenger was using his mobile in the toilet.

[overalls]

Smoke allarms in dash 8 baggage bays dont like having phones placed near them.

Several occasions when the baggage smoke light has come on in flight.

There was even a sb/mod done to place the smoke detector in a specially bonded and earthed cage. This did help but still happens from time to time.

[Dave Gittins]

Can say with pretty near certainty that my mobile (in my shirt pocket) has interfered with the transponder signal. On one occasion outbound from Luton VFR in a PA-28, the mobile phone sound in the headphones corresponded with ATC saying our transponder signal had just disappeared. Turned phone off, somewhat red faced, and ATC confirmed transponder was back on. This in a well equipped FM immune aeroplane.

Don't know what else it could be as the transponder never failed before or since.

In an earlier life of mine, mobile phones reqularly played absolute havoc with water treatment works instrumentation when within 6-8 feet. The chlorine analysers instead of giving a steady 0.25 ppm readout, suddenly started giving all sorts of wierd results in the 10 - 50 ppm range. This was on triple validated equipment that was supposedly fully RF protected to some BS or other.

The effect was only noticeable over short ranges though, and on an aeroplane I would doubt that anybody more than 10 feet from the equipment racking would have any effect.

[natus82]

Well people i'm the sad boy who started all this,

The CAA have evidence proving that mobile phones affect aircraft in flight, it mostly affects the navigational systems but it has been known to have other affects such as the fire alram in the hold.
The danger is only a real danger at an apparent distance of 30 cm to the wires or instrumentation, at any other distance there was very little dange of interference.
I myself left my phone on when i went to Ibiza, i did genuinely forget but when we landed i had 3 messages that i'd recived during the flight, evidently the plane didn't crash and i'm still here.
But be warned anyone wanting to keep it turned on during flight will get there arses whooped, recently a man got 8 months jail time for refusing to turn his phone off on a UK filght, i think the maximum time is 2 years imprisonment.
I personally think that there is no danger with just a handful of people carrying phones, but the problem arises when everyone could be using a phone at once, then there could be problems.......it's all or nothing

:ok:

[Captain Stable]

natus, I think you will agree that your anecdotal experience does not prove that mobile phones prove no danger to aircraft.

It simply establishes that, as far as you are aware, there was no catastrophic result from any interference that may have occurred on that occasion, in your phone's location on board that flight, with that particular aircraft.

I see comments time and time again on here to the effect of "Well, I've left my phone on and not crashed", but this is hardly a rigorous approach to research.

The CAA have carried out huge levels of research into the subject. It is available on their website. Go look at it.

Whether you may think it is valid or not, they are the regulatory auithority in the UK. They say it is illegal and dangerous.

Airlines follow their advice on the subject. If people ignore the airlines' and their Captain's orders to switch off, they are breaking the law. That is why people have been prosecuted.

[avioniker]

Here's another link to a forum with a slightly less experienced group talking generally about this same subject:

http://www.airliners.net/discussions/tech_ops/read.main/77210/

[maxmobil]

Anyone to tell me mobiles don't cause problems inflight would have a hard time to convince me:

A few years ago overhead a russian city suddenly my A320 PF showed something never experienced before and after again: "rhytmic" switching of the PFD side stick order indication on and off (first time ever i saw this in cruise).
This not being enough, ECAM caution "EIU failure" came on, resulting in "reverser isolation valve fault". I suspected EMI and immediately grabbed for the PA microphone, commanding ALL passenger electric appliances being switched off.

And guess what? Ten seconds later all systems back to normal...

[TURIN]

Most people who drive with a mobile phone clamped to their earhole don't have crashes. That's no consolation to the poor bu99ers who get run down at a bus stop by white van man asking for directions is it?

If you get my drift.

[maxmobil]

See,
when Niki Lauda still had his Airline, he once stated in the media that he "?will give permission to passengers soon to use the mobile phones during flight, because I have tried a few approaches with two mobile phones operating in the cockpit and nothing happened"

Clever guy he is, coincidally he had a PR-contract with a mobile phone network paying him aprox. EUR 280,ooo per year. THAT certainly wouldn't influence his opinion, no?

[barbiedoll]

Was sent this today, indirectly related to topic!!

FODC 30-2003 Mobile Phones
Use of cellular telephones during aircraft refuelling

.... the CAA is satsified that fuel vapour ignition, due to the use of cellular telephones on the aircraft, is unlikely when passengers are on board during fuelling operations. This position takes account of the energy levels of the cellular phone transmissions, absorption and attenuation of that energy within the cabin and the seperation that would exist between an onboard cellular telephone and an external fuel vapour source.

... it is proposed to combine CAP74 and CAP434 "Aviation Fuel at Aerodromes" into a new document and to remove the text relating to the use of telephones by passengers on board during refuelling operations. Pending the revision, operators may relax their current restriction and permit the use of cellular phones inside the aircraft during fuelling operations":


confused:

[avioniker]

There really shouldn't be much confusion on the subject.
The energy required to cause ignition of fuel (btu's) is relatively high when compared to the energy required to cause RF signal disruption (milli Watts or decibels).
I'm glad at least one country's regulatory agencies are paying attention to basic physics.

[EasyBaby]

Regarding the use of mobile phones at petrol stations, Esso Garage Portabello Edinburgh has too accidents recently, on two different occasions members of the public have set fire to themself and petrol vapors at this garage, Why would you even want to chance it?
Thats why is p**sess me off big style when pax are on their phones while sitting at the overwings, sure its only 5 tons of fuel next to you!

[Dr. Red]

On a related note, cellphones have been known to upset life support equipment in hospitals. I haven't heard of anyone dying as a result though.

It would appear that any digital equipment is vulnerable to cellphone interference, provided the conditions are just right. As someone already mentioned, it looks like the older analogue cellphones, with higher energy emissions, are the main offenders.

Even if the risk of critical interference is very small, we should still take steps to control it.

[FE Hoppy]

Easy Baby,
Could you direct me to a report of these cell phone induced accidents or is it just speculation that mobile phones were the cause?

[bookworm]

Regarding the use of mobile phones at petrol stations, Esso Garage Portabello Edinburgh has too accidents recently, on two different occasions members of the public have set fire to themself and petrol vapors at this garage, Why would you even want to chance it?
Thats why is p**sess me off big style when pax are on their phones while sitting at the overwings, sure its only 5 tons of fuel next to you!

Ah yes it's back!

Here's what the Mobile Manufacturers' Forum says:
Mobile Phones and Petrol Station Safety (http://www.mmfai.org/files/files/publications/MMF_Viewpoint_PetrolStations.pdf)

and here's what the Institute of Petroleum says:

Ignition of flammable vapour by mobile phones not substantiated by technical evidence (http://www.intellectuk.org/press/news/ip_release_mobile_phones_petrol_stations.pdf)

Do also bear in mind that the fuel that the pax are sitting next to is Jet A1, not petroleum spirits like 100LL or Mogas.

[Fragman88]

Hi there,

A search with my name and `interference' will lead you to some good info. This previous thread contains a few references (including my own) of actual RFI ocurrences, including mobile phones. .........Sorry can't seem to get the link to come up directly!

Good Luck:ok:

[radeng]

The fact that on various occasions, having a 'phone on has been 'got away with' doesn't prove it's safe. Although the integrity of shielding of cables is good in a new a/c, that doesn't necessarily hold over the a/c life. Additionally, the effect of one mobile phone is very different to the effect of a number of them, while not even all new a/c equipment is quite as immune to EMC as might be desirable. Older ones (a well known victim is the Tornado fighter!) can be very prone to problems.

As a professional radio engineer who has been involved with the development of EMC Standards for radio, I'm very much in favour of keeping ALL mobile phones very definitely OFF while in flight. I really don't want to be SLF on the one occasion it all goes wrong! Yes, I know there's two highly trained skilled bodies up at the sharp end, but even they can get overwhelmed when things start going wrong..................

The comments about fuel dangers is a different matter - there was a paper from Sheffield University at a Mobile Radio Conference some 20 odd years ago that showed that at powers under about 5 watts, the energies available in induced sparks were insufficient to ignite petrol. I believe there's also a BS (Btish Standard) on the subject somewhere: there's a DEF STAN as well on RADHAZ that covers fuel and explosive ignition amongst the other good stuff.

[gulf clubber]

Fish,

just to refresh your morse code ... - - - ... is SOS, the code received on mobiles is SMS ... - - ...

M = dah dah

petty I know, but I dont get the opportunity to use my morse skills nowadays

Cheers
Clubber