Mobiles ring out air warning
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They may not cause planes to fall out of the sky but...
The WestWinds flying on the nightshifts SY-ML, ML-AD, SY-AD etc obviously had girlfriends/wives/mistresses who kept late hours as well. Most nights at least one of their calls would be accompanied by the static from their operating mobile. I don't know about the Lap tops but I wouldn't be surprised if mobile phones screw around with all sorts of things. Recieving a call just now sitting at the computer has caused the static sound to come through the speakers. Not an engineer so not qualified to have an opinion though.
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I think there's a couple of possibly critical factors here, not yet discussed.
1) The proximity of the TRANSMITTING mobile, to critical aircraft control and navigation wiring lumes running alongside the cabin... ? (more detail from any engineers out there?)
2) A mobile remains dormant (so to speak), when out of range, such as in high altitude cruise etc but has maximum output/interference when sending and recieving calls, once in range. This appears to be when the most trouble documented has been encountered.
Safety first!
1) The proximity of the TRANSMITTING mobile, to critical aircraft control and navigation wiring lumes running alongside the cabin... ? (more detail from any engineers out there?)
2) A mobile remains dormant (so to speak), when out of range, such as in high altitude cruise etc but has maximum output/interference when sending and recieving calls, once in range. This appears to be when the most trouble documented has been encountered.
Safety first!
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I still do NOT believe this is a problem. 
On the Aircraft I mentioned before, where sometimes all 3 people in the cockpit would be on mobile phones at once, there was also a normal mobile phone (well I guess not actually a mobile
) fitted to the rear wall of the cockpit and powered from the Aircraft's electrical system, and NONE of these phones ever caused any problems.
The only difference with the "fixed" phone, although always powered, was that the ringer was disabled during flight so as not to startle the Crew at a critical stage of flight.
On the Aircraft I mentioned before, where sometimes all 3 people in the cockpit would be on mobile phones at once, there was also a normal mobile phone (well I guess not actually a mobile
) fitted to the rear wall of the cockpit and powered from the Aircraft's electrical system, and NONE of these phones ever caused any problems. The only difference with the "fixed" phone, although always powered, was that the ringer was disabled during flight so as not to startle the Crew at a critical stage of flight.
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As the reports and ensuing discussion are based on a UK CAA report I thought I'd step in with some background from us here in blighty.
For the cynics especially you should be aware of this:
Two years ago I attended a CAA conference on additional 'glass' in the flight deck. This meant imported glass - they wanted to encourage, improve and 'de-impede'
the adoption of laptop and PDA devices for performance planning, nav plates Etc. New guy in charge and new attitude. We all held hands and had a group hug. Question regarding cell phones came up and boffins wheeled out to say that the basic principles of how the phones poll, lock on and the power transmitted were a total non event but they were going to carry out a formal study.
Roll forward 18 months and the report comes out - total change of attitude. The things many have noted over the years occured under rigorous test conditions.
Yes, they may not have ever happened to you in the aircraft you fly but they are now proven. For the truly cynical you have to ask this question of the report: What's in it for them?? Mobiles are already completely banned in all phases of flight. Other electronics in certain phases.
This damascene conversion is embarrassing to them and I'm so much more cynical than you guys because I wonder what was edited out of the original drafts!!!!!
Regards
Rob
For the cynics especially you should be aware of this:
Two years ago I attended a CAA conference on additional 'glass' in the flight deck. This meant imported glass - they wanted to encourage, improve and 'de-impede'
the adoption of laptop and PDA devices for performance planning, nav plates Etc. New guy in charge and new attitude. We all held hands and had a group hug. Question regarding cell phones came up and boffins wheeled out to say that the basic principles of how the phones poll, lock on and the power transmitted were a total non event but they were going to carry out a formal study.Roll forward 18 months and the report comes out - total change of attitude. The things many have noted over the years occured under rigorous test conditions.
Yes, they may not have ever happened to you in the aircraft you fly but they are now proven. For the truly cynical you have to ask this question of the report: What's in it for them?? Mobiles are already completely banned in all phases of flight. Other electronics in certain phases.
This damascene conversion is embarrassing to them and I'm so much more cynical than you guys because I wonder what was edited out of the original drafts!!!!!
Regards
Rob
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Used to fly a surveillance aircraft that had a whopping great digital pulse radar strapped to it alongside a whole host of other electronic goodies that never seemed to have any effect on the nav equip. After reading the aircraft certification notes for the surveillance mod I was surprised as to how little effort had been put into countering the effects of EMF. BTW I have produced only Girls!
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Having been an engineer responsible for installing the most vast array of unusual electronic systems in to aircraft, I have only on one ocasion had an ocurrence of RFI. It was an IDME interfearing with a GPS RX due to proxcimity of the antennas. This is of course a well known problem now, and is usually avoided at installation.
The number of computers, and telephones, and radio transmitters that I have installed ain't small, and it has been my experience that very little upsets aircraft systems.
My experience has seen all sorts of electronic equipment used at all sorts of locations in the most electronically complex of aircraft and I have never seen a systems performance effected. Laptop and mobile telephone in the cockpit or the E&E bay, both in use, no problem. Digital imaging computers in aircraft with hills hoists strung around them to pulse massive em pulses in to the ground, no problem.
What I see surrounding the EMI/RFI claims of interference to aircraft systems is a whole lot of anecdotal evidence, linking system malfunctions to a coincidence. eg. the autopilot malfunctioned, and there was a laptop turned on in the cabin nowhere near the INS or the autopilot, but since the laptop was there it must have caused the malfunction!!
As for the study, from what I know of EMI RFI on aircraft trhough experience, I would love to get a copy of the methods, if anyone can point me in the right direction, please do!!
The number of computers, and telephones, and radio transmitters that I have installed ain't small, and it has been my experience that very little upsets aircraft systems.
My experience has seen all sorts of electronic equipment used at all sorts of locations in the most electronically complex of aircraft and I have never seen a systems performance effected. Laptop and mobile telephone in the cockpit or the E&E bay, both in use, no problem. Digital imaging computers in aircraft with hills hoists strung around them to pulse massive em pulses in to the ground, no problem.
What I see surrounding the EMI/RFI claims of interference to aircraft systems is a whole lot of anecdotal evidence, linking system malfunctions to a coincidence. eg. the autopilot malfunctioned, and there was a laptop turned on in the cabin nowhere near the INS or the autopilot, but since the laptop was there it must have caused the malfunction!!
As for the study, from what I know of EMI RFI on aircraft trhough experience, I would love to get a copy of the methods, if anyone can point me in the right direction, please do!!
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Depends on the Phone type.
Ive had GSM Phones caused bad ( Oh **** turn that off NOW) static on VHF radio's in, Tobago's, C210, C182 & C172's. CDMA phone dont have any noise whatsoever on C210, C310, PA31.
Wasnt there a report out not long ago that said that these problems had only been found in Boeing- No reports of interferance problems in Airbus????
Wasnt there a report out not long ago that said that these problems had only been found in Boeing- No reports of interferance problems in Airbus????
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The CAA report titled " Effects of Interference from Cellular Telephones on Aircraft Avionic Equipment "here
The term "avionics" equipment should be noted as this is exactly what was tested.
The testing involved simulation of electronic equipment, including mobile phones operating 30cm from avionics equipment. The conclusion:
-Compass froze or overshot actual magnetic bearing.
-Instability of indicators.
-Digital VOR navigation bearing display errors up to 5 degrees.
-VOR navigation To/From indicator reversal. VOR and ILS course deviation indicator errors with and without a failure flag.
-Reduced sensitivity of the ILS Localiser receiver.
-Background noise on audio outputs.
The equipment covered in testing was:
"...VHF communications, VOR Navigation, Localiser and Glide Slope equipment, together with a gyro- stabilised remote reading magnetic compass."
I wonder what effect, when held 30 cms from such equipment, a ferromagnetic material would have?
The term "avionics" equipment should be noted as this is exactly what was tested.
The testing involved simulation of electronic equipment, including mobile phones operating 30cm from avionics equipment. The conclusion:
-Compass froze or overshot actual magnetic bearing.
-Instability of indicators.
-Digital VOR navigation bearing display errors up to 5 degrees.
-VOR navigation To/From indicator reversal. VOR and ILS course deviation indicator errors with and without a failure flag.
-Reduced sensitivity of the ILS Localiser receiver.
-Background noise on audio outputs.
The equipment covered in testing was:
"...VHF communications, VOR Navigation, Localiser and Glide Slope equipment, together with a gyro- stabilised remote reading magnetic compass."
I wonder what effect, when held 30 cms from such equipment, a ferromagnetic material would have?
Last edited by Perpetual_Hold_File; 29th Sep 2003 at 05:43.
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Perpetual Hold File,
Thanks for posting the link. I have read the lab report, and over the next couple of days will critically analyse it, and report back to here, but the good news is that just on the surface of it, it won't take me too much effort to completely discredit their findings. Straight off, the equipment that they tested is old GA stuff, not installed in any fashion like it would be in an aircraft, they blasted the equipment with exaggerated levels of RF radiation from directional antennas. They failed to re-create a realistic senario, and more over made no attempt to duplicate an airliner style situation. What you said about generating the same effects with a piece of iron is correct in the case of the compas, and also I have to ask, what about all the equipment that they didn't test, those that are actually likely to be truly effected by RFI from telephones, that is GPS, DME, TCAS, Transponder, autopilot, IRS............
Thanks for posting the link. I have read the lab report, and over the next couple of days will critically analyse it, and report back to here, but the good news is that just on the surface of it, it won't take me too much effort to completely discredit their findings. Straight off, the equipment that they tested is old GA stuff, not installed in any fashion like it would be in an aircraft, they blasted the equipment with exaggerated levels of RF radiation from directional antennas. They failed to re-create a realistic senario, and more over made no attempt to duplicate an airliner style situation. What you said about generating the same effects with a piece of iron is correct in the case of the compas, and also I have to ask, what about all the equipment that they didn't test, those that are actually likely to be truly effected by RFI from telephones, that is GPS, DME, TCAS, Transponder, autopilot, IRS............
