Mobile phone signal interference... all lies??
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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.
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.
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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.
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.
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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!
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!
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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 !"
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 !"
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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.
Airline standard TSO quality avionics are a different kettle of fish altogether.
Yes, even twenty five year old ones.
Gee, I wonder why....
'Tis a wonder they work at all.
Hey, I tried to be nice.
Airline standard TSO quality avionics are a different kettle of fish altogether.
Yes, even twenty five year old ones.
Gee, I wonder why....
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And I did'nt know that airline standard equipment was of better quality ! Thanks for the heads up 
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..................?
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..................?
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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.
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.
Originally Posted by RMC
There are more people out there who have had radio interference from ONE mobile phone than those who have not. (...) This ignited the fuel vapours and seriously burnt his gonads....checkout the "no mobile phone use" signs at garages these days.
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.
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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.
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.
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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.
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.
Last edited by el !; 2nd Aug 2006 at 11:28.
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Originally Posted by selfin
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.
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.
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.
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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.
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.
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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/
A bit of basic info, easy to understand for everyone about the frequencies used in europe is given at:
http://www.techmind.org/gsm/
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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?
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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.
Cellphones are much more powerful so there is still some concern and resistence.
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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.
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.
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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.
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.
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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.
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.
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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 ?
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 ?
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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
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