Mobile Telephones in Aircraft
Join Date: Apr 2000
Location: FL, USA
Posts: 357
Likes: 0
Received 0 Likes
on
0 Posts
The relaxing of the taxi-in rule in the US was the result of a very long extensive study by American Airlines' Tulsa Tech unit and the FAA. No aircraft interference could be reproduced, blah blah...so hence the new situation.
As the SWA poster put it earlier, people love it. I actually think it can substantially reduce congestion outside Arrivals at the terminal, as Limos etc, can wait off-base and drive with perfect timing for a pick-up as the plane taxis in.
As the SWA poster put it earlier, people love it. I actually think it can substantially reduce congestion outside Arrivals at the terminal, as Limos etc, can wait off-base and drive with perfect timing for a pick-up as the plane taxis in.
Join Date: Jul 2002
Location: The bar of the Frog and Peach
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
My boss is both an aerospace EMC engineer with many years of experience and mobile phone junkie but has absolutely no time for mobile users in aircraft. She has been known to tell off fellow passengers who try to use them.
FlapsOne: I manage to do without one all the time.
FlapsOne: I manage to do without one all the time.
I call you back
Join Date: Nov 2001
Location: Alpha quadrant
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
I am not a mobile phone engineer but I am aware that the
antennae they use only have a limited angle of sweep. The angle of tilt ( something like a wx radar ) determines where a signal is available. It would seem obvious that in the UK which doesn't have any high mountains that the angle of tilt would be always very low particularly in densely populated areas.
Also in Europe where each country has licensing rights for moblile companies a higher tilt angle would result in signals crossing borders more often ( it is a problem as it is ) avoiding roaming charges or getting unwarranted roaming charges.
A combination of the above might explain why in NW Europe you don't get a signal above 1000' and also why in the USA it is possible .
antennae they use only have a limited angle of sweep. The angle of tilt ( something like a wx radar ) determines where a signal is available. It would seem obvious that in the UK which doesn't have any high mountains that the angle of tilt would be always very low particularly in densely populated areas.
Also in Europe where each country has licensing rights for moblile companies a higher tilt angle would result in signals crossing borders more often ( it is a problem as it is ) avoiding roaming charges or getting unwarranted roaming charges.
A combination of the above might explain why in NW Europe you don't get a signal above 1000' and also why in the USA it is possible .
Join Date: May 2003
Location: Surrey
Age: 43
Posts: 900
Likes: 0
Received 0 Likes
on
0 Posts
I had just heard that because as the phone gains height it gets line-of-sight for multiple cells of the network, and this causes lots of problems so that in the end the phone provider will disconnect the phone.
I've taken my mobile glidng loads of times and it will work fine up to maybe 2000ft but after that the signal just goes.
I've taken my mobile glidng loads of times and it will work fine up to maybe 2000ft but after that the signal just goes.
Interference from Mobile Phones
I think we have run to ground that phones do work in the air - at least up to 2 or 3 thou. I can't speak about higher than that but 9/11 certainly indicates that they do as do Mrs BB's welcome messages across every country between Gatwick and Dalaman.
They also "roam" when near borders. On one Turkish trip, I got loads of messages welcoming me to Greece.
Personally I am at the beck and call of the damn thing all day and a good excuse like, I was on an aeroplane, suits me fine until I am in the terminal.
I can also attest to them interfering with aircraft equipment - at least transponders. I have occasionally forgotten to turn off the phone in my shirt pocket and on one particular occasion It blocked my transponder signal, as Luton were quick to tell me. They said they had lost my squawk (whilst I was about 2 miles away and 1500 ft), just as I heard the characteristic "chatter" of the phone in my headset. I switched the phone off, told Luton I had recycled the transponder, and they confirmed that it had just come back again.
I try and pay more attention now and it is a final check pre take off announcement to my pax - Can you please check that you've turned your phones off ???.
I would expect more safety critical systems - like the FBW to be more robust to RF intereference - FM immune indeed !!
In the past, I have found phones to interfere with all manner of electrical equipment that isn't too RF immune. The "chatter" that affects TVs, my clock radio, landline phones etc. has a hell of an effect on other things, I used to have a major effect on on-line analytical equipment in water treatment plants in a previous life and sent the dosing pumps haywire.
Have heard that easyJet's checklists have mobiles off - on the pre-take off ..... and mobiles on - on the after landing.
DGG
They also "roam" when near borders. On one Turkish trip, I got loads of messages welcoming me to Greece.
Personally I am at the beck and call of the damn thing all day and a good excuse like, I was on an aeroplane, suits me fine until I am in the terminal.
I can also attest to them interfering with aircraft equipment - at least transponders. I have occasionally forgotten to turn off the phone in my shirt pocket and on one particular occasion It blocked my transponder signal, as Luton were quick to tell me. They said they had lost my squawk (whilst I was about 2 miles away and 1500 ft), just as I heard the characteristic "chatter" of the phone in my headset. I switched the phone off, told Luton I had recycled the transponder, and they confirmed that it had just come back again.
I try and pay more attention now and it is a final check pre take off announcement to my pax - Can you please check that you've turned your phones off ???.
I would expect more safety critical systems - like the FBW to be more robust to RF intereference - FM immune indeed !!
In the past, I have found phones to interfere with all manner of electrical equipment that isn't too RF immune. The "chatter" that affects TVs, my clock radio, landline phones etc. has a hell of an effect on other things, I used to have a major effect on on-line analytical equipment in water treatment plants in a previous life and sent the dosing pumps haywire.
Have heard that easyJet's checklists have mobiles off - on the pre-take off ..... and mobiles on - on the after landing.
DGG
Join Date: Jan 2001
Location: Location, Location
Posts: 642
Likes: 0
Received 0 Likes
on
0 Posts
I'd be happy to bet that any flight with more than (say) 100 pax will have at least one (probably several) active mobiles on board - whether due to ignorance, carelessness, bloody-mindedness or whatever. Since, thankfully, we don't observe flights dropping out of the sky, I assume that any risks from the operation of such devices are minimal.
I'm all in favour of minimising the (already miniscule) risk of commercial flight, but in the real world where (it seems as though) almost everyone over the age of 7 has a mobile, you can't eliminate the possibility that one will be operating inadvertently.
I'm all in favour of minimising the (already miniscule) risk of commercial flight, but in the real world where (it seems as though) almost everyone over the age of 7 has a mobile, you can't eliminate the possibility that one will be operating inadvertently.
Join Date: Sep 2003
Location: Fleetwood
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
The phone ban is a sensible precaution due to the miriad of avionic equipment in use and age spread.
Remember that not all avionics of the same class are born equal. Early equipment would not have endured the necessary EMC testing at the mobile/celular frequencies in use today. Also consider that the EMC issue isnt just pick up from antenna and receiver front ends, but also through wiring looms.
The same is true for the ban in hospitals, although I loose the logic there when you see mobile phone antenna on the roof of a hospital!
Personally I believe mobiles should be banned from public places full stop!! hehehe
Remember that not all avionics of the same class are born equal. Early equipment would not have endured the necessary EMC testing at the mobile/celular frequencies in use today. Also consider that the EMC issue isnt just pick up from antenna and receiver front ends, but also through wiring looms.
The same is true for the ban in hospitals, although I loose the logic there when you see mobile phone antenna on the roof of a hospital!
Personally I believe mobiles should be banned from public places full stop!! hehehe
Join Date: May 2001
Location: Area 52
Posts: 180
Likes: 0
Received 0 Likes
on
0 Posts
Not long ago I was deadheading on WN from KLAS to KRNO. After takeoff the fellow sitting across the aisle started his laptop and called up a webpage! I then noticed a cell card in his pcmcia slot, blinking merrily. He did lose signal rather quickly, but that is pretty normal as the area between KLAS and KRNO is desolate and cell phones do not work well even on the ground. This incident has made me rethink the cell phone policies, as how do we define what is a cell phone and what is not. All sorts of devices are out there which use cell phone technology, but bear no resemblence to a "cell phone".
Join Date: Mar 2003
Location: THE BIG SUNNY SANDPIT
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
About a year ago i was watching an inquest into the RAF CH-47 that crashed into the Mull-of-Kintyre in Scotland and they mentioned the possibily of a mobile phone signal being a contributing factor. It was stated that in the UK only mobile phones connected the the Orange network could interfere with the avionics on board due to the frequency being used by that network. I don't know what frequencies are used or if things have changed since the accident but if it was brought up in an offical investigation then i must believe that there is some truth to it.
On a slightly different note egnm has just banned the use of mobile phones until pax are inside the main terminal building. They have deemed that people using a mobile are not paying full attention to their surroundings and so are a health and safety hazard to themselves and others. I wonder haw many other airports will follow suit?
On a slightly different note egnm has just banned the use of mobile phones until pax are inside the main terminal building. They have deemed that people using a mobile are not paying full attention to their surroundings and so are a health and safety hazard to themselves and others. I wonder haw many other airports will follow suit?
Join Date: Jun 2003
Location: All over the place!
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
Sounds like someone had something against Orange. Actually, all of the mobile networks use the same range of frequencies. That's why, if you try, you can attempt to log into other network providers with your phone. They then validate it throw you out if they don't like you.
Join Date: Oct 2003
Location: Lee Gardens
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
let's not forget pda's
sony ericcson P800 and Treo , and of course O2 XDA have an inbuilt phone. so a pax seemingly playing nintendo could be text messaging somebody if there is a connection.
my five cents worth, Fl 310, on a direct to KLARK, a pax h/p was still logged on AT & T wireless.
my five cents worth, Fl 310, on a direct to KLARK, a pax h/p was still logged on AT & T wireless.
If you think that interference from cellphones is bad, you should see what plod radios do to my TV!
I think the record I've had for 'networks available' at ground level was around 9 or 10 in Friedrichshafen - some German, some Swiss and some Austrian..... But the phone didn't get too confused!
The way forward must be approved 801.11b or g W-LAN systems in aircraft linked to the Internet. Then people could e-mail their contacts - SILENTLY!! None of this "Yeah, 'ello Jim, it's Ray. I've been to see Alec and the buyer says..zz..zz.." which you get in loud voices in most trains these days. SHUT UP you rude $ods - go and stand in the carriage entrance if you must use your spiv phone in the train!
I think the record I've had for 'networks available' at ground level was around 9 or 10 in Friedrichshafen - some German, some Swiss and some Austrian..... But the phone didn't get too confused!
The way forward must be approved 801.11b or g W-LAN systems in aircraft linked to the Internet. Then people could e-mail their contacts - SILENTLY!! None of this "Yeah, 'ello Jim, it's Ray. I've been to see Alec and the buyer says..zz..zz.." which you get in loud voices in most trains these days. SHUT UP you rude $ods - go and stand in the carriage entrance if you must use your spiv phone in the train!
None but a blockhead
Join Date: Nov 1999
Location: London, UK
Posts: 535
Likes: 0
Received 0 Likes
on
0 Posts
BEagle--
I think the real answer is coming down the line - ultrawideband, or UWB. The standard's still cooking -- 802.15.3a -- but it promises to provide hundreds of megabits a second over wireless. The really good thing is that it's ultra low power: the FCC approval for the system states that the transmitters aren't allowed to emit any more power than ordinary electronic equipment without transmitters radiate anyway. So you shouldn't be able to tell the difference between a laptop with no radio and one using UWB. On any particular frequency, it just looks like a very low level noise source.
Not that people haven't been worried -- UWB transmits on all bands simultaneously (arm wave, arm wave), and there have been worries that enough of these things in a small place could significantly raise the noise floor on the GPS frequencies. Tests so far seem to be fine, and the standard will most certainly be immune to one of the more dangerous forms of interference where a signal is picked up by a piece of equipment, rectified and turned into DC that then messes up normal functioning. There's just not enough power there to do that.
The downside to UWB is that it's low range - ten metres max. However, that's probably an advantage in an aircraft, where you can have UWB gateways in each seatback (or row of seats) and get very high densities of usage with very low overall power levels.
R
I think the real answer is coming down the line - ultrawideband, or UWB. The standard's still cooking -- 802.15.3a -- but it promises to provide hundreds of megabits a second over wireless. The really good thing is that it's ultra low power: the FCC approval for the system states that the transmitters aren't allowed to emit any more power than ordinary electronic equipment without transmitters radiate anyway. So you shouldn't be able to tell the difference between a laptop with no radio and one using UWB. On any particular frequency, it just looks like a very low level noise source.
Not that people haven't been worried -- UWB transmits on all bands simultaneously (arm wave, arm wave), and there have been worries that enough of these things in a small place could significantly raise the noise floor on the GPS frequencies. Tests so far seem to be fine, and the standard will most certainly be immune to one of the more dangerous forms of interference where a signal is picked up by a piece of equipment, rectified and turned into DC that then messes up normal functioning. There's just not enough power there to do that.
The downside to UWB is that it's low range - ten metres max. However, that's probably an advantage in an aircraft, where you can have UWB gateways in each seatback (or row of seats) and get very high densities of usage with very low overall power levels.
R
