Using mobiles on planes.
OLD RED DAMASK
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As a fairly frequent flyer.If all airlines say on the pre flight briefing, "Turn off all electronic devices", how is it 50% just continue as if nothing has been said. Ignorance, being the objective type against all rules in society??
Last time I remonstrated with the guy in the next seat, he shouted out at the top of his voice, "What are you? The mobile phone police?"
Some people just choose to be moronic.
Last time I remonstrated with the guy in the next seat, he shouted out at the top of his voice, "What are you? The mobile phone police?"
Some people just choose to be moronic.
. Made up.. I'm happy to listen to an intelligent argument as to why it is dangerous. Trolly dollies need not apply, most of you haven't got a clue.
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Yes, they used to be legal. It was the cell blockers that were used in museums, symphony halls, movie theaters, and other public places. ACLU took it to court as violation of free speech, and won.
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Maybe not in newer equipment but....
Tuned new freq. can't hear ATC over squeals and pops... Check crew pockets, turn off cellphones, freq. now clear.
Happened often enough that if we couldn't hear on a freq we checked our phones. Most of the time, problem solved.
On GIISPs 2001-2003.
Happened often enough that if we couldn't hear on a freq we checked our phones. Most of the time, problem solved.
On GIISPs 2001-2003.
Join Date: Jan 2002
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The problem isn't that modern mobile phones cause modern aircraft systems to go bananas. The problem is that when a bunch of people are yabbering away on their phones they are not receptive to instructions from crew members. The general hubub and babble means that even people not on their phones don't listen either. Belts don't get put on, emergence briefs aren't listened to and the result is a herd of monkeys that don't act properly in the event of an emergency. Old analogue phones did cause problems - the transmission power of an old analogue phone was up to 4 watts and I still have a panasonic in the garage that has an output power of 4 watts. But modern digital phones transmit up to 0.5w and to preserve battery life usually transmit about a tenth of that. So other than the characteristic polling noise that is usually caused by me leaving my own phone on in the cockpit I find it hard to believe that serious technical problems can be caused by phones being switched on.
But in the event of needing to evacuate an aircraft in a hurry I can well imagine that having a significant proportion of them yabbering away to their mistresses could cause a dangerous delay. Getting the folks in the back to sit still and be alert to messages is a good idea.
The shape of a mobile phone mast transciever means that the beam is horizontally polarised and doesnt really work over a couple of thousand feet in most circumstances. So the polling for a cell by a phone increases dramatically once at height. Which runs down the battery and is bloody annoying if it causes radio interference (but to be fair, the only phone thats ever caused that on an aircraft I've been flying is my own).
Devices exist which detect a polling phone. If it was a problem the crew would sweep the cabin before take off. They don't, and there's the clue.
But in the event of needing to evacuate an aircraft in a hurry I can well imagine that having a significant proportion of them yabbering away to their mistresses could cause a dangerous delay. Getting the folks in the back to sit still and be alert to messages is a good idea.
The shape of a mobile phone mast transciever means that the beam is horizontally polarised and doesnt really work over a couple of thousand feet in most circumstances. So the polling for a cell by a phone increases dramatically once at height. Which runs down the battery and is bloody annoying if it causes radio interference (but to be fair, the only phone thats ever caused that on an aircraft I've been flying is my own).
Devices exist which detect a polling phone. If it was a problem the crew would sweep the cabin before take off. They don't, and there's the clue.
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CAN'T WAIT
Just think of all the business and financial data you could suck off of all of those poorly protected phones while on the plane with you.. And they could never claim privacy... after all what privacy in an over sized city bus with wings. Perhaps this should be looked at as a coming business opportunity. Fresh Insider Data for Euros.... Dollars.. etc 
Last edited by gleaf; 30th Apr 2013 at 21:28.
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Aviation tech cannot be accessed by outsiders. Android or otherwise.
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FCC
I heard recently that the FCC keeps the restriction in place because phones accessing cell towers from altitude can cause them to to all wonky? Would be funny for all of this to mainly be a ground based problem.
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The old analog & digital technology did fall over if many cell registrations were attempted from a signal mobile, such as from an aircraft where the phone can receive many base stations due to its height - it was designed as a ground based communications system. However, the whole question needs to consider that the AC is generally a well designed and maintained bit of kit. The phone is mass produced to the cheapest price and is more likely to emit spurious signals than an AC. If things do go wrong, the AC problem is more likely to be picked up at the appropriate maintenance period. When was the last time you had your mobile phoned checked/serviced? And even if you have, I would guess price was a driving force in the job, and not standards. If you want to prevent the possibility of an accident due to radio interference, mobiles need to be off (or in flight mode) during flight. Taking a domestic piece of kit into a professional AC and *never* expecting interference is "pie in the sky" - unless its in flight mode. If you wanted to test every phone ever produced against every AC ever produced, to see if they interfer, you could. However, it would be prohibativly expensive. Much safer/cheaper to require all mobiles be turned off.
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A320 fcom fcb electronic interference from portable equipment carried on by passengers:
airlines often wonder whether they should allow passengers to operate electronic devices in the cabin without any limit. Federal aviation regulation (far) section 91.19 allows passengers to operate: • portable voice recorders • hearing aids • heart pacemakers • electric shavers • any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used. It is obvious that the myriad portable devices that now exists or that may be available in the future cannot be tested. ‐ as far as aircraft specific electrical flight controls and engine control computers on airbus aircraft are concerned, there is no chance of their operation being affected by passenger-operated electronic devices, due to the high level of protection applied to these systems. ‐ nevertheless, this question arises for navigation and communication receivers and is applicable to any aircraft. A study has been conducted by an rtca (radio technical commission for aeronautics) special commitee. ‐ the conclusion is that the probability of a passenger-operated device interfering with the ils localizer during a typical flight is about one in a million. Airbus industrie recommendations is that no portable device should be used during take-off and landing. ‐ concerning radio phones airbus industrie recommends to prohibit the use of those devices.
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We tried a little experiment one CAVOK day by testing a mobile in flight.
The CDI bar and VOR needles went mad. “Well, there is some truth in the don’t-use-in-flight idea”.
Actually, we had flown directly over the Newcastle VOR, hence the indications! Nothing to do with the use of the phone.
The CDI bar and VOR needles went mad. “Well, there is some truth in the don’t-use-in-flight idea”.
Actually, we had flown directly over the Newcastle VOR, hence the indications! Nothing to do with the use of the phone.
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There are several systems that can be installed on aircraft, from corporate to commercial, that allow the use of mobile phones. There are several Airbus SB's for GSM on board systems for example (called OMTS). I know this as we have it installed on our aircraft (A319)
These systems install a pico cell on the 'plane that effectively vastly reduces the phones power output so that interference is less likely. The installation of these systems also requires an EMI check following installation to ensure no unexpected interference occurs.
The system works worldwide, except in the airspace of those countries where the regulatory authorities do not allow its use. In which case the on board pico cell shuts down and mobile phone signs illuminate.
I have it on good authority (the system provider) that in the vast majority of airspace where the system cannot be used (the USA is a notable exception) the reasons are financial and not due to safety concerns. In a nutshell the ground based regulators want a slice of the cake for allowing use of mobile phones in their airspace.
As has been stated before, the original thread has nothing to do with the use of 'phones on board aircraft, but refers to hacking into ground/air datalinks or interfering with navigation signals which could be done from anywhere and would require quite a bit more than a mobile phone 'app'.
These systems install a pico cell on the 'plane that effectively vastly reduces the phones power output so that interference is less likely. The installation of these systems also requires an EMI check following installation to ensure no unexpected interference occurs.
The system works worldwide, except in the airspace of those countries where the regulatory authorities do not allow its use. In which case the on board pico cell shuts down and mobile phone signs illuminate.
I have it on good authority (the system provider) that in the vast majority of airspace where the system cannot be used (the USA is a notable exception) the reasons are financial and not due to safety concerns. In a nutshell the ground based regulators want a slice of the cake for allowing use of mobile phones in their airspace.
As has been stated before, the original thread has nothing to do with the use of 'phones on board aircraft, but refers to hacking into ground/air datalinks or interfering with navigation signals which could be done from anywhere and would require quite a bit more than a mobile phone 'app'.
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No quality airline should allow the use of cell phones in flight because it presents a nuisance for fellow travellers! If some LCC's need the extra revenue and/or need to lure young very important consultant kids to fill their planes, ok.
Imagine a business cabin full of Italians ( or any other heavy communicating nation ) constantly using their phones on a night flight and you can clearly imagine this horror scenarion. Contrary to AI pilots I need my good sleep in flight mode and be fit on arrival.
Imagine a business cabin full of Italians ( or any other heavy communicating nation ) constantly using their phones on a night flight and you can clearly imagine this horror scenarion. Contrary to AI pilots I need my good sleep in flight mode and be fit on arrival.
.........because it presents a nuisance for fellow travellers !
The fact that the actions of Carruthers at the extremity of the Empire couldn't be instantly advised to the seat of Government, was a Good Thing.
Ever since then it has been downhill.
Ban the b****dy things.
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There was a Q400 in Australia some years ago that declared an emergency and diverted to Sydney due to a baggage compartment fire indication. Fire bottles were discharged and pax evacuated on a taxiway... the cause? Mobile phone in checked baggage that had been left on intefered with smoke detectors.
Lucky there were no animals in the hold as they wouldn't have coped too well once extinguishers were fired.
Lucky there were no animals in the hold as they wouldn't have coped too well once extinguishers were fired.
Last edited by Mr Whippy; 11th May 2013 at 01:19.
Thread Starter
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Seems to make little difference no matter what the airlines/FAA/CAA/Pprune members decide ....
Rules, shmules: Fliers leaving devices switched on in droves ? The Register
Rules, shmules: Fliers leaving devices switched on in droves ? The Register
Last edited by Alanwsg; 11th May 2013 at 07:28.
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A lot of rubbish
A lot of rubbish is spouted here from some folk that know nothing about EMI in modern kit. Cellphones should not 'interfere' with any modern aircraft receiver.
No avionics operates on cellphone frequencies
No cellphone operates on avionics frequencies
Therefore there are only two main possibilities
The airborne receiver has spurious response on cell phone frequencies or it is overloaded by the cellphone either at RF, IF or even in the audio chain.
The option is to make a better receiver, adequately filtered.
or
The cellphone has a spurious output, a spur that is slap bang on a used avionic frequency. This may be more likely as they are cheaply made but phones are certified under FCC regulations to not produce out of band frequencies above a certain level.
The possibility of the second option is low IMHO due to the nature of the emissions from cellphones. Therefore Airbus et al need to spend a few more pennies adding some caps, ferrite cores, stub filters or whatever to stop their avionics responding to out of band signals.
Simple.
No avionics operates on cellphone frequencies
No cellphone operates on avionics frequencies
Therefore there are only two main possibilities
The airborne receiver has spurious response on cell phone frequencies or it is overloaded by the cellphone either at RF, IF or even in the audio chain.
The option is to make a better receiver, adequately filtered.
or
The cellphone has a spurious output, a spur that is slap bang on a used avionic frequency. This may be more likely as they are cheaply made but phones are certified under FCC regulations to not produce out of band frequencies above a certain level.
The possibility of the second option is low IMHO due to the nature of the emissions from cellphones. Therefore Airbus et al need to spend a few more pennies adding some caps, ferrite cores, stub filters or whatever to stop their avionics responding to out of band signals.
Simple.
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I'm always confused and amused to be told upon landing, when paxing with with easyJet, that mobiles must remain switched off until inside the terminal building. When I'm at work at the same airport there is no mention of such a rule and we use mobiles with impunity right up until push back. Not that anyone listens anyway, while said announcement is being made a cacophony of beeps and rings fills the cabin.
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It is possible for a transmitter to interfere with nearby electronics, anyone who's held a GSM phone near their hifi has probably heard the characteristic noise it makes.
All electronic kit that has regulatory approval is tested to check that it is immune to such interference, up to a given field strength. For consumer kit that's usually 2V/m, for vehicles I think it's 50V/m. I don't know if aircraft are considered to be vehicles or whether there is a more specific standard, but there should be a documented set of tests on an aircraft with the equipment fitted.
However, it is always possible that limits can be exceeded, there are tales of the road past RAF Fylingdales where vehicles would misbehave if the radar was operational, and field strengths in excess of 50V/m have supposedly been recorded. That's over 6.6W/m^2 when expressed as a power density. A mobile phone doesn't put out much power, but if it happens to excite a resonant structure, it can generate quite a high field strength. One cannot be sure that there isn't such a structure, which could be a bit of metal trim on a suitcase in a particular place in the hold close to some of the internal wiring. A possible hole in the cheese.
There is also the fact that the test sample passed, but if someone missed a bolt, or a bit of corrosion has occurred in the wrong place, a production unit may be susceptible to a bit of RF power. One would hope that with all the checks on aircraft that this is unlikely, but for corrosion to be found it has to exist for some time between checks. It's another hole in the cheese.
On a purely practical note, GSM has a speed limit. If you're flying towards the phone mast at 500mph then it's not going to cope too well, although one off to the side will have a lower relative speed and it's going to work. If you're sticking to lower speeds under FL100 then you'll probably get away with it down that low.
To finish on a personal note, I think anyone wanting to use a mobile phone on an aircraft should be aware that the fuselage is going to degrade the signal, and also that other passengers may not appreciate the phone use, and so go outside to make the call.
All electronic kit that has regulatory approval is tested to check that it is immune to such interference, up to a given field strength. For consumer kit that's usually 2V/m, for vehicles I think it's 50V/m. I don't know if aircraft are considered to be vehicles or whether there is a more specific standard, but there should be a documented set of tests on an aircraft with the equipment fitted.
However, it is always possible that limits can be exceeded, there are tales of the road past RAF Fylingdales where vehicles would misbehave if the radar was operational, and field strengths in excess of 50V/m have supposedly been recorded. That's over 6.6W/m^2 when expressed as a power density. A mobile phone doesn't put out much power, but if it happens to excite a resonant structure, it can generate quite a high field strength. One cannot be sure that there isn't such a structure, which could be a bit of metal trim on a suitcase in a particular place in the hold close to some of the internal wiring. A possible hole in the cheese.
There is also the fact that the test sample passed, but if someone missed a bolt, or a bit of corrosion has occurred in the wrong place, a production unit may be susceptible to a bit of RF power. One would hope that with all the checks on aircraft that this is unlikely, but for corrosion to be found it has to exist for some time between checks. It's another hole in the cheese.
On a purely practical note, GSM has a speed limit. If you're flying towards the phone mast at 500mph then it's not going to cope too well, although one off to the side will have a lower relative speed and it's going to work. If you're sticking to lower speeds under FL100 then you'll probably get away with it down that low.
To finish on a personal note, I think anyone wanting to use a mobile phone on an aircraft should be aware that the fuselage is going to degrade the signal, and also that other passengers may not appreciate the phone use, and so go outside to make the call.