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EGLD
13th Oct 2002, 10:42
This happened in April, but reported in todays Sunday Mirror

Embraer 145 on approach to Manchester sent out of control when woman switched on her mobile phone

Aircraft "careered across the sky" as "instrument dials and electronic systems seized up". Pilot notified crew and passengers to prepare for emergency landing by opening the cockpit door, at which time he saw the said stupid bint on her phone, told her to turn it off, and the problems immediately went away

I can reproduce the article if needed, but its the standard article with gratuitous use of the phrases "disaster!" "lost control!" "avoiding action!" "crash moments away!"

Anyone know any more? feel free to delete/point me in the right direction if its been discussed before, couldnt find anything via search

18-Wheeler
13th Oct 2002, 13:41
It's reported by the media so it's safe to say that the majority of the report is a bunch of cow flop, but there is a distinct chance of a mobile doing odd things to the aeroplane's avionics.
I've seen it happen on a 747 on the ground, with the pressurisation system so they really can affect the systems of some planes.

411A
13th Oct 2002, 17:48
Never mind mobile phones....a certain middle east operator had a B747SP do a high dive in the mid-eightys mid-Atlantic because the aft outflow valve fully opened when they called Gander on the #2 HF.:eek:
Seem to recall that this was a on-going problem with this particular aeroplane.

radio ears
13th Oct 2002, 20:36
Take a look at http://news.bbc.co.uk/1/hi/england/2324259.stm

Eboy
13th Oct 2002, 20:47
Here is the Mirror version . . .

http://www.sundaymirror.co.uk/homepage/news/page.cfm?objectid=12278447&method=sm_full&siteid=81959

I have my doubts. I'd be more confident if I read The Economist's version.

mattpilot
14th Oct 2002, 00:16
i wouldn't be suprised if phones are now banned in the cabin. Imagine 10 terrorists in the plane all turning their cell-phones on at once and making calls. :cool: Hey, whatever excuse works for the regulatory body. :rolleyes: :rolleyes:

Earthmover
14th Oct 2002, 00:46
An engineer told me .... hang on, that sounds like a song .... Anyway, an engineer told me that some cellphones operate within a quarter of one percent of DME frequencies.

Hearsay though, anyone confirm?

Airbubba
14th Oct 2002, 03:31
>>...an engineer told me that some cellphones operate within a quarter of one percent of DME frequencies.
>>Hearsay though, anyone confirm?

Well, DME runs from 962 to 1213 MHz (see http://www.rduafss.faa.gov/navaids/dme.htm ).

GSM 900 has an allocation from 925 to 960 (paired with 880 to 915 MHz, see http://www.gsmworld.com/technology/spectrum/frequencies.shtml ).

The gap from 960 to 962 MHz is 2 MHz which is indeed less than .25% of 960 which would be 2.4 MHz.

The engineer is right.

British phone freqs may be more dangerous than others (especially if they can topple a jungle jet <g>) according to this article: http://abcnews.go.com/sections/living/DailyNews/cellphone000510.html

PaperTiger
14th Oct 2002, 04:19
One would think (purported) serious control difficulties on approach would cause the AAIB to investigate. I find no reference on their site.

Ballast
14th Oct 2002, 07:59
I would not get so hung up about how close they are in frequency, closeness causes desensitisation or blocking, and equipment is usually designed to cope with this. What is harder to design to is protection against harmonic interferance, either direct or combined with additive/subtractive elements internally or externally. Taking a very simple case:

You want to listen to 121.5Mhz. In order to handle this frequency the radio needs it converting to an intermediate frequency, say 10.7Mhz. The radio needs to run an oscillator at 110.8Mhz which when combined with the required signal gives 10.7 Mhz (121.5 - 110.8 = 10.7). However, another frequency of 100.1 Mhz also gives 10.7Mhz (110.8Mhz - 100.1Mhz = 10.7 Mhz). Therefore as well as receiving 121.5 the radio will receive signals on 100.1Mhz (probably KISS FM in London UK).

THe above is over simplified to give clarity, techniques such as multiple intermediate frequencies etc can overcome the problem.

But now add in a mobile phone. These frequency hop whilst in use and use pulsed modulation (particularly good at producing rich harmonics) Therefore there is a good source of frequencies for any radio equipment to "mix" with causing problems.

In practice much mobile phone interference is also caused after the RF stages in the more poorly protected audio stages.

So whilst it is possible to design in protection it is easier to reduce the opportunity for it to occur (ie. switch the damn things off).

Notso Fantastic
14th Oct 2002, 15:08
I read about devices that restaurants etc could buy to disable all mobile transmissions in the room and render phones useless. I would have thought it was worth developing these for use in aeroplanes so no phones worked when engines were running. Yes, I know they would use transmissions themselves, but people will never be stopped from using their phones in flight as long as they work.

As a side issue, Notso carried out 'experiments' with an Orange phone a few years back. It never worked in the air. Presumably the cells detected a flooding effect and cut you out of the system, but mysteriously on the ground it worked, so how come these people can get their phones to work? I am also reliably informed that Virgin phones similarly don't work in the UK when airborne.

btmtdi
14th Oct 2002, 15:22
Hey my Virgin phone struggled to get a signal in the middle of London - not surprised that you couldn't get a signal at altitude.

Yours, now a BTCellnet user,

Globaliser
14th Oct 2002, 16:41
Isn't it because the bases and phones are relatively short range transmitters, which is why you can go out of range so quickly? I think that's also why you hear so much beeping on final approach, as the phones finally get close enough to bases to pick up the SMS messages that have been queuing to be delivered.

Of course, that's the part of the flight at which I think I'd least like to experience mobile phone-induced LOC ...

peeteechase
14th Oct 2002, 18:22
I read a report about two years ago relating to a helicopter which experienced a cargo fire warning, fortunately while still on the ground. An active mobile phone was found in the baggage, switched off and the flight continued without incident.
After September 11th, I would think that any inflight emergency would result in many passengers picking up their mobiles and trying to say goodbye, particularly in the caser of cabin crew with marginal english describing bomb threats!
I agree that a ban would be the only answer.
ATB, PTC

marlowe
14th Oct 2002, 19:13
about 2 years ago was on an embraer145 departing GLA when an
engine shut down on takeoff roll, returned to stand and an
engineer said that it was due to a mobile phone being switched on and recieving a call, checked PAX in rear 3 rows of a/c and found phone switched on with a text message recieved took 40 mins to reboot computers.

Awakevortice
14th Oct 2002, 22:17
My diesel landy departed GLA with vague steering and oil leaks all over the place. I found my nokia on in the back, switched it off, now the car performs like new!
Perhaps it was the same sort of phone as in the Embraer 145 and all the other mobile works of fiction?

mattpilot
14th Oct 2002, 22:21
maybe its the bermuda... err the london triangle thats causing all these problems? :cool: :cool:

Notso Fantastic
15th Oct 2002, 09:58
Very funny. Well I got this enormous credit card bill that made the whole place rock, and I turned off my mobile phone, and guess what? It was still there rockin'!

brain fade
17th Oct 2002, 01:24
Get real people!
I fly the 145 for a living and have gotten airborne on loads of occasions with one or both of our personal phones inadvertantly left on. the 'chirrp' as it loses the cell is invariably heard on the i/c prompting a 'switch off' asap. never seen any evidence of interference, and that with the phone(s) on the flight deck!
don't believe everything you read in the papers.:)

arcniz
17th Oct 2002, 01:34
This thread engages at least two different aircraft-related issues:

a) In an era of ubiquitous cellphones and various other portable electonics that can transmit complex powerful signals in and around aircraft, a high degree of RF-resistance & microwave toughness should be considered in the design specs and the maintenance standards for every component on passenger aircraft.

The standards should apply not only to the obvious resonant interference with nav/comm systems, but also particularly to sensors and control actuators throughout the aircraft, and also the connected wiring + innards of analog and digital control circuits and computers. Virtually everything electrical, in sum.

Goal: Properly designed and maintained passenger aircraft should be immune to the effects of cellphones and other (out of band) onboard RF sources across the entire spectrum.

b) Even when and if the standards of a) are uniformly and stringently effected, some RF-introduced random problems with avionics, controls, and systems will continue to occur, just as mechanical problems do. Many will be for the same reasons: vibration and corrosion effects can gradually unmake the high-quality electical joints and seals needed for robust RF insensitivity.

Given that a) isn't going to completely happen for some while, and b) is going to continue happening forever, limits on use of inflight cellphones continue to be reasonable.

However, the appropriate post-incident response to suspected cellphone-type systems malfunction incidents should be a full writeup and aggressive troubleshooting to find, repair, and document the faulty subsystem. One may think of the troublesome phones as canaries for fundamental problems that require repair in any case.

18-Wheeler
17th Oct 2002, 05:59
Brain fade, I saw it happen right in front of me. Jolly good luck to you if your plane is safe from interferance, though I would try to be a little more scientific when determining if a mobile affects the systems or not.

Iron City
17th Oct 2002, 13:28
This month's number of Popular Science magazine in US has a small article on some test work NASA did on one or more United 737s on the ramp with broadband radio emissions. Apparantly the broadband radio uses all kinds of frequenci4es and hops all over the place putting fundamental emissions and harmonics as well as whatever leaky IF gets out in frequencies used for transponders, ACAS/TCAS, and other supposidly protected bands.

US Federal Communications Commission appears to have approved the comemrcial broadband for 3GEN cell phones etc and must see visions of spectrum auctions dancing in it's head but does not appear concerned with effects on safety. The industry pooh poohs any concern also (big suprise).

Plane*jane
19th Oct 2002, 22:44
Last week on approach to EDI very short final, the aircraft moved left 30 degrees + off the localiser and dropped below glidepath purposely and smoothly. Captain and I after disbelief seconds recovered the situation PDQ but had we been in IMC and not good VM as we were, a certain go around. Hostie then advises us afterwards that a mobile had started ringing after the wheels were down but not exactly sure where on the approach.
Neither of us were sure if we had heard the usual buzzing in our headphones, but taking no chances have given full report to safety who have subsequently reinforced throughout the company the "switch the mobile off" speech and stamping it out from the FD if we hear anything in future.
The scarey thing was the way it looked as though one of us had just decided to turn off the path. I suppose thinking about mobile interference I might have expected the systems to disengage or jolt somewhat with the usual cavalry charge lights flashing warnings but it didn't. It just seemed to set a new course........one to watch

stormin norman
20th Oct 2002, 12:15
A few years back a Captain reported a 747 classic could not engage any A/pilot due to a mobile phone being left on in the cabin .

ejector seat
9th Nov 2002, 15:01
Found this on another forum dated 8th November - has anyone else heard about this 'incident'? (Spelling uncorrected)

I just thought I would share with you my interesting experience this evening.
I am a frequent traveller with xxx commuting to Belfast Aldergrove,
Edinburgh and Glasgow a couple of times a month and over the past 12 months
have never experienced any problems what so ever, however tonight was very
different.

We took of from Belfast as normal 35 min journey back into Liverpool. On
approach into Liverpool the "fun" started, it was very bumpy and the plane
was swaying from left to write (quite concerning). The pilot then came over
the intercom stating "could you switch your mobile phone off". The plane
then made a sharp turn to the right, I honestly thought the pilot was going
to roll the aircraft however he seemed to straighten the aircraft up and
managed to land. When we landed the pilot said "please stay seated when we
reach the terminal building and the engines have been switched off there
is something I need to tell you". Anyway to cut a very long story short he
told us that we had encountered a serious incident, we just missed the power
station hence the sharp turn to the right. He then came out of the cockpit
left the plane for a couple of minutes then re entered with 2 police officers,
they went straight to the culprit who had turned the phone on and arrested
him (I have not got a clue how they new it was him)..................what
an idiot!!!!

Roadtrip
9th Nov 2002, 15:26
In the US, the FAA and FCC is supposidly considering allowing the use of cell phones in the air. The problem, accoring to "them" appears primarily with airborne phones accessing more than one ground station, causing thus clogging up the cellular phone system. There's a fix for this they claim . . . . FWIW.

Fox3snapshot
9th Nov 2002, 23:34
ATC COMMS

In our ATC centre the comms are all digital interface with TID selection. When a GSM (mobile) is left on in the centre (against local orders I might add) the phone when it searches, or for a worst example actually rings...WILL block our frequency and transmits the electrical interference sound you here when your phone is near car radio's/CD Players/Speakers etc. To that end a supressor has been installed to jam the signals of peoples phones. Additionally when a pilot transmits to ATC and there is GSM in the flight deck searching etc. we receive the interference at our end. If you have ever placed your phone next to the PC when it goes off, just watch the screen go bezerk. Still some unknowns with these little puppies I think.

:confused:

slater6000
11th Nov 2002, 17:35
I think it would be a very brave company (or body) that outlawed phones on flights, most of the population own them!

And there goes the business traveller if he cant take his mobile brain tumour unit with him on his flight. Net-meeting, e-mail, fax, Conference lines and the like are all taking a bite at the flying cherry (no matter what the adverts say regarding face to face business).

Along the lines of a similair thread, I do beleive it is quite easy to block the phone's signal using a thin sheet of aluminium (similair to baking foil, sprinkled with fairy dust or some other technology!!) but who pays to upgrade the a/c? Vodafone, Orange etc?. OR....

There goes the pay-rise next year!!!!

One more thing, its been a year or so since I was on pprune..It really is quite a magnificent site. Well done boys and girls.

18-Wheeler
11th Nov 2002, 23:07
I reckon that all the mobile's should be rounded up before the flight & put into a safe box, to ensure that they're turned off. Give the owner a ticket to make sure they get the right one back, etc.
Or just crush them in a vice, whatever ...

echomikeecho
12th Nov 2002, 20:31
18W

Nice idea, but in practice, do you really think this is workable? "Well is was working when I gave it to you! You broke it, that £250 please!" "They're not having my phone I'll just hide it away." Remember the magority of the pax are fine but there are always wallies!

Self Loading Freight
12th Nov 2002, 22:16
There's a lot of disinformation in this area, and not that many facts. However, Lufthansa has said that on average, one phone is left switched on on every flight it makes. I'd be surprised if that wasn't true for just about everyone. If there was a problem, it would have surfaced by now. And it would have been fixed -- you can have seat-mounted radiation detectors, crew-carried radiation detectors, small blocking transmitters in the cabin that prevent phones from working during flight, screening film on the windows... lots of options, none of them free but then since when is safety free?

In any case, you ain't seen nothing yet. As well as cellular radio services on four frequencies, there are 802.11, 802.11b, 802.11a, Zigbee (aka 802.15.4), Bluetooth, WirelessUSB, UWB (which is ALIEN TECHNOLOGY, I tell ya), cordless mice on 49, 433 and god knows what MHz... and that's off the top of my head. Some or all of the above is already part of those sleek silver gadgets called personal digital assitants, smartphones, pocket PCs, MP3 players or whatever, and more is on its way. I've seen an MP3 player that has a built in frequency-agile Band II broadcast FM transmitter (www.neurosaudio.com) to let you listen through your hifi or car stereo without wires. Band II broadcast FM is right next door to VOR frequencies... but it's just an MP3 player, right?

Not only will the cabin crew not be able to tell whether someone's using a transmitter during the flight, neither will the people using them. Every electronic gizmo, whether it's turned on or not and whether it looks as if it will radiate or not, will have the ability to wake up and spurt something into the ether, of its own accord.

That's next year. Intel, bless, is already talking about building broadband wireless networking into every chip it makes -- as in every processor, memory chip, pc glue chip, you name it -- because it's close to making this a zero-cost option. This won't be for a couple of years. Maybe five.

The battle -- to make the cabin an RF-free or RF-controlled environment -- has already been lost. The only option is to think defensively, identify problems before they become critical with existing equipment and to design for the actual environment. The days when only policemen and radio nerds had portable transmitters died in the 80s.

R

paulo
12th Nov 2002, 22:34
I hate vegetables. Recently, I found prrune running quite slowly, and on inspecting the fridge, what did I see? I threw them out and then rechecked prrune and it was faster. [sigh]