So PEDs are okay on board?
Oct 11th, 2008 | 08:33 AM
#21
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The NZ article is only the tip of a really dangerous iceberg. Read the second article I linked. The folks at an internationally accredited electrical engineering institute have serious doubts about the safety of <u>all</u> sources of radio-frequency radiation brought on board and used by passengers - cell phones, radio receivers including GPS, laptops, Bluetooth devices, PDAs, games, music players...
http://www.spectrum.ieee.org/mar06/3069
I will re-iterate from that article a quote that I think is nothing less than bone-chilling: "...the data support a conclusion that <b>continued use of portable RF-emitting devices such as cellphones will, in all likelihood, someday cause an accident</b> by interfering with critical cockpit instruments such as GPS receivers. This much is certain: there exists a greater potential for problems than was previously believed."
http://www.spectrum.ieee.org/mar06/3069
I will re-iterate from that article a quote that I think is nothing less than bone-chilling: "...the data support a conclusion that <b>continued use of portable RF-emitting devices such as cellphones will, in all likelihood, someday cause an accident</b> by interfering with critical cockpit instruments such as GPS receivers. This much is certain: there exists a greater potential for problems than was previously believed."
Oct 11th, 2008 | 09:10 AM
#22
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ooohhh,
watch out, the planes are falling out of the sky.....
hundreds of thousands of flights a day all over the world, millions of laptops, iPODs, etc... being used on all these flights.
better write your congressperson to stop this insanity......
watch out, the planes are falling out of the sky.....
hundreds of thousands of flights a day all over the world, millions of laptops, iPODs, etc... being used on all these flights.
better write your congressperson to stop this insanity......
Oct 11th, 2008 | 09:22 AM
#23
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That line of "reasoning" is known as The Gambler's Fallacy.
Hundreds of thousands of normal 747 flights preceded the TW800 disaster, when an obscure defect in the design of the 747 fuel system blew up the plane, killing all 230 on board in a horrific breakup scenario.
The more PEDs are used on board, the greater the odds of a catastrophe. Have someone who understands statistical inference and risk analysis read the IEEE report to you.
Hundreds of thousands of normal 747 flights preceded the TW800 disaster, when an obscure defect in the design of the 747 fuel system blew up the plane, killing all 230 on board in a horrific breakup scenario.
The more PEDs are used on board, the greater the odds of a catastrophe. Have someone who understands statistical inference and risk analysis read the IEEE report to you.
Oct 11th, 2008 | 09:45 AM
#24
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so, should be ban all cars that don't get checked daily for brakes, or steering or whatever? because they will on occasion cause accidents and in some cases, deadly accidents. Perhaps it's not 200 people at the same time, but when you add it up daily, then I will take a guess, but I believe more people die because of some others not taking care of their cars on regular basis. Should we ban alcohol all together? Lots of alcohol related deadly accidents, fights, arguments. Should we ban red meat, you know, the stuff that will eventually give you a heart attack if consumed in large quantities.
Your argument is ridiculous. Not one plane fell to the ground because of PEDs, not one that I know of. Yet, you want to ban the use of PEDs because of a chance of it happening one day according to somebody's statistics?
Your argument is ridiculous. Not one plane fell to the ground because of PEDs, not one that I know of. Yet, you want to ban the use of PEDs because of a chance of it happening one day according to somebody's statistics?
Oct 11th, 2008 | 11:58 AM
#26
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The nzherald article doesn't really say much of anything: a laptop is being investigated as the cause.
It mentions a July incident where a wireless mouse was blamed. Blamed does not mean guilty.
I read parts of the ieee article and saw that they tested for emissions in the passenger compartment. Did they do any measuring of intereference in the cockpit of that originated in the passenger compartment? Did seem that the EEs who wrote the article had their minds made up even before their experiments.
Here is an article from a trusted (by me) source:
http://tinyurl.com/54ktas
"Qualification levels related to high-intensity radiated fields (HIRF) for new airplane equipment are higher than almost any level of emissions from passenger PEDs."
Among much else, it does recognize the potential from newer PEDs.
Last night I saw an article somewhere about the potential for digital tv broadcasts to be disrupted by a wireless internet system that would use the "white space" between the tv broadcast frequences.
It mentions a July incident where a wireless mouse was blamed. Blamed does not mean guilty.
I read parts of the ieee article and saw that they tested for emissions in the passenger compartment. Did they do any measuring of intereference in the cockpit of that originated in the passenger compartment? Did seem that the EEs who wrote the article had their minds made up even before their experiments.
Here is an article from a trusted (by me) source:
http://tinyurl.com/54ktas
"Qualification levels related to high-intensity radiated fields (HIRF) for new airplane equipment are higher than almost any level of emissions from passenger PEDs."
Among much else, it does recognize the potential from newer PEDs.
Last night I saw an article somewhere about the potential for digital tv broadcasts to be disrupted by a wireless internet system that would use the "white space" between the tv broadcast frequences.
Oct 11th, 2008 | 11:58 AM
#27
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I hesitate to get into any arena with AAFF and Robespierre, but I want to ask about distinctions between cellphones and other 'PEDs' -- I skimmed the Spectrum article and it seems to focus on cellphones, otherwise just saying that all 'PEDs" on a generic list "emit radiation."
But some are designed to actually transmit and receive signals -- e.g., a cellphone, a WiFi-equipped (and active) laptop, and a wireless mouse. In addition, the article said that there are significant variations among cellphones, cellphone types, frequency bands affected, and so on. There's plenty of room for much more study.
It seems to me that it's folly to argue from past history as a guarantee of future performance (viz., the stock market), but it's also probable that a blanket ban of all "PEDs" isn't ultimately necessary (even if it were feasible).
I would LOVE it if no one could ever use a cellphone in the air, under any circumstances. But it does seem some more refined scrutiny of what does and doesn't cause problems at which frequencies/bands, in what circumstances, would be prudent and more enlightening than an all-or-none debate.
But some are designed to actually transmit and receive signals -- e.g., a cellphone, a WiFi-equipped (and active) laptop, and a wireless mouse. In addition, the article said that there are significant variations among cellphones, cellphone types, frequency bands affected, and so on. There's plenty of room for much more study.
It seems to me that it's folly to argue from past history as a guarantee of future performance (viz., the stock market), but it's also probable that a blanket ban of all "PEDs" isn't ultimately necessary (even if it were feasible).
I would LOVE it if no one could ever use a cellphone in the air, under any circumstances. But it does seem some more refined scrutiny of what does and doesn't cause problems at which frequencies/bands, in what circumstances, would be prudent and more enlightening than an all-or-none debate.
Oct 11th, 2008 | 01:24 PM
#28
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<i>"Qualification levels related to high-intensity radiated fields (HIRF) for new airplane equipment are higher than <b>almost</b> any level of emissions from passenger PEDs."</i>
Doesn't that <i>almost</i> bother anyone else? It says that there <u>are</u> passenger PEDs that exceed even the new limits - and the statement says nothing about older equipment, which probably constitutes 90% of the planes in the air.
<i>But it does seem some more refined scrutiny of what does and doesn't cause problems at which frequencies/bands, in what circumstances, would be prudent and more enlightening than an all-or-none debate.</i>
The scariest part of the problem is that the frequency and intensity of spurious emissions that can be generated by malfunctioning equipment cannot be predicted at all. We know what some of the failure modes <i>might</i> be - and design against them - but it is a fact of physics that all of them cannot be imagined.
I think we're on very thin ice - and I hope to gollygosh I'm wrong.
Doesn't that <i>almost</i> bother anyone else? It says that there <u>are</u> passenger PEDs that exceed even the new limits - and the statement says nothing about older equipment, which probably constitutes 90% of the planes in the air.
<i>But it does seem some more refined scrutiny of what does and doesn't cause problems at which frequencies/bands, in what circumstances, would be prudent and more enlightening than an all-or-none debate.</i>
The scariest part of the problem is that the frequency and intensity of spurious emissions that can be generated by malfunctioning equipment cannot be predicted at all. We know what some of the failure modes <i>might</i> be - and design against them - but it is a fact of physics that all of them cannot be imagined.
I think we're on very thin ice - and I hope to gollygosh I'm wrong.
Oct 11th, 2008 | 06:00 PM
#29
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I have yet to read of an accident caused by RF emissions from any personal electronic device on board an aircraft, even those that are transmitters by design.
Furthermore, the prohibitions that exist and those that are practiced do not coincide with the theoretical risks. Devices that may produce a great deal of RF emissions are allowed, while others that probably produce none are prohibited. And some that should theoretically be prohibited are ignored, such as electronic watches (nobody has ever conclusively determined that electronic watches do not interfere with aircraft avionics, even though the law requires this).
Overall, the risk is massively overstated. If an airliner can withstand a direct strike by lightning (and it can), the feeble emissions of laptops and video cameras aren't going to make a difference. Even a cell phone isn't going to make much difference, since any system sensitive enough to be perturbed by a cell phone inside the aircraft would also be vulnerable to transmissions from outside, which are legion.
There are other risks that are much more important, such as those created by airlines that pressure their pilots to load only the minimum amount of fuel required by law, or airlines that give pilots such erratic working hours that they fall asleep in the cockpit, or passengers who insist on smoking in the toilets.
Furthermore, the prohibitions that exist and those that are practiced do not coincide with the theoretical risks. Devices that may produce a great deal of RF emissions are allowed, while others that probably produce none are prohibited. And some that should theoretically be prohibited are ignored, such as electronic watches (nobody has ever conclusively determined that electronic watches do not interfere with aircraft avionics, even though the law requires this).
Overall, the risk is massively overstated. If an airliner can withstand a direct strike by lightning (and it can), the feeble emissions of laptops and video cameras aren't going to make a difference. Even a cell phone isn't going to make much difference, since any system sensitive enough to be perturbed by a cell phone inside the aircraft would also be vulnerable to transmissions from outside, which are legion.
There are other risks that are much more important, such as those created by airlines that pressure their pilots to load only the minimum amount of fuel required by law, or airlines that give pilots such erratic working hours that they fall asleep in the cockpit, or passengers who insist on smoking in the toilets.
Oct 11th, 2008 | 06:32 PM
#30
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<i>I have yet to read of an accident caused by RF emissions from any personal electronic device on board an aircraft, even those that are transmitters by design.</i>
The discussion isn't about past accidents - it's about the potential for future ones. But devices that are transmitters by design are the last place I would expect a problem to come from, because they are engineered to limit spurious and sideband emissions. Electronic toys and other things that aren't expected normally to transmit are not.
<i>Furthermore, the prohibitions that exist and those that are practiced do not coincide with the theoretical risks. Devices that may produce a great deal of RF emissions are allowed, while others that probably produce none are prohibited. And some that should theoretically be prohibited are ignored, such as electronic watches (nobody has ever conclusively determined that electronic watches do not interfere with aircraft avionics, even though the law requires this).</i>
We'll get a better handle on which ones are riskier from examining the crash sites.
<i>Overall, the risk is massively overstated. If an airliner can withstand a direct strike by lightning (and it can), the feeble emissions of laptops and video cameras aren't going to make a difference. Even a cell phone isn't going to make much difference, since any system sensitive enough to be perturbed by a cell phone inside the aircraft would also be vulnerable to transmissions from outside, which are legion.</i>
Avionic systems know what the broadband noise signature of a lightning bolt looks like, and they're trained to ignore it (their common-mode rejection ratios are very high). The problem will come when a PED emits something that looks very much like normal data that the system fails to recognize as extraneous.
<i>There are other risks that are much more important, such as those created by airlines that pressure their pilots to load only the minimum amount of fuel required by law, or airlines that give pilots such erratic working hours that they fall asleep in the cockpit, or passengers who insist on smoking in the toilets.</i>
Let's talk about other risks tomorrow.
The discussion isn't about past accidents - it's about the potential for future ones. But devices that are transmitters by design are the last place I would expect a problem to come from, because they are engineered to limit spurious and sideband emissions. Electronic toys and other things that aren't expected normally to transmit are not.
<i>Furthermore, the prohibitions that exist and those that are practiced do not coincide with the theoretical risks. Devices that may produce a great deal of RF emissions are allowed, while others that probably produce none are prohibited. And some that should theoretically be prohibited are ignored, such as electronic watches (nobody has ever conclusively determined that electronic watches do not interfere with aircraft avionics, even though the law requires this).</i>
We'll get a better handle on which ones are riskier from examining the crash sites.
<i>Overall, the risk is massively overstated. If an airliner can withstand a direct strike by lightning (and it can), the feeble emissions of laptops and video cameras aren't going to make a difference. Even a cell phone isn't going to make much difference, since any system sensitive enough to be perturbed by a cell phone inside the aircraft would also be vulnerable to transmissions from outside, which are legion.</i>
Avionic systems know what the broadband noise signature of a lightning bolt looks like, and they're trained to ignore it (their common-mode rejection ratios are very high). The problem will come when a PED emits something that looks very much like normal data that the system fails to recognize as extraneous.
<i>There are other risks that are much more important, such as those created by airlines that pressure their pilots to load only the minimum amount of fuel required by law, or airlines that give pilots such erratic working hours that they fall asleep in the cockpit, or passengers who insist on smoking in the toilets.</i>
Let's talk about other risks tomorrow.
Oct 12th, 2008 | 11:05 AM
#33
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<i>Author: mrwunrfl
Date: 10/12/2008, 02:26 pm
"almost any level" simply means that they tested to a level well beyond any real world scenario.</i>
I think that's a rather cavalier interpretation of the phrase. I take it to mean "most, but not all" - as in
"Qualification levels related to high-intensity radiated fields (HIRF) for new airplane equipment are higher than <s>almost any level of</s> [most, but not all] emissions from passenger PEDs."
Date: 10/12/2008, 02:26 pm
"almost any level" simply means that they tested to a level well beyond any real world scenario.</i>
I think that's a rather cavalier interpretation of the phrase. I take it to mean "most, but not all" - as in
"Qualification levels related to high-intensity radiated fields (HIRF) for new airplane equipment are higher than <s>almost any level of</s> [most, but not all] emissions from passenger PEDs."
Oct 12th, 2008 | 11:41 AM
#34
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<i>folly to argue from past history as a guarantee of future performance (viz., the stock market)
It is not folly in this case. It is physics.</i>
These articles describe a mosaic of anecdotal events - past history - that forms a threatening pattern:
http://www.boeing.com/commercial/aer..._textonly.html
http://www.spectrum.ieee.org/mar06/3069
It is a fact that no direct causal link between PEDs and flight systems anomalies has been documented - at least none that can be reproduced under similar but different conditions. But it is also a fact that certain combinations of coincident conditions capable of affecting flight safety <u>have</u> occurred.
In several instances, air crew could verify the role of a PED affecting aircraft control by turning it off, noting that the anomaly ceased, then turning it on again, whereupon the anomaly reasserted itself.
The fact that these "relationships" cannot be reproduced in the laboratory is insignificant. What matters is that they <u>have</u> occurred - <i>in flight</i>. Since the exact nature and extent of the threat cannot be quantified, I feel that until it can, the operators should err on the side of caution.
It is not folly in this case. It is physics.</i>
These articles describe a mosaic of anecdotal events - past history - that forms a threatening pattern:
http://www.boeing.com/commercial/aer..._textonly.html
http://www.spectrum.ieee.org/mar06/3069
It is a fact that no direct causal link between PEDs and flight systems anomalies has been documented - at least none that can be reproduced under similar but different conditions. But it is also a fact that certain combinations of coincident conditions capable of affecting flight safety <u>have</u> occurred.
In several instances, air crew could verify the role of a PED affecting aircraft control by turning it off, noting that the anomaly ceased, then turning it on again, whereupon the anomaly reasserted itself.
The fact that these "relationships" cannot be reproduced in the laboratory is insignificant. What matters is that they <u>have</u> occurred - <i>in flight</i>. Since the exact nature and extent of the threat cannot be quantified, I feel that until it can, the operators should err on the side of caution.
Oct 12th, 2008 | 12:46 PM
#35
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What is insignificant is the nz herald article and the blame (by who?) that a wireless mouse caused a plane to go off course. The didn't prove it, did they? Or did they repeatedly during that flight click the mouse and see the plane go off course?
The wireless mouse is blamed but that doesn't mean it was guilty. An airline suspects a laptop that is not the same as saying that it was the cause.
That is the same Boeing article that I linked. It does say: "as a result of these and other investigations, Boeing has not been able to find a definite correlation between PEDs and the associated reported airplane anomalies".
That Boeing article is cautious in what it says.
But it is not hysterical.
The wireless mouse is blamed but that doesn't mean it was guilty. An airline suspects a laptop that is not the same as saying that it was the cause.
That is the same Boeing article that I linked. It does say: "as a result of these and other investigations, Boeing has not been able to find a definite correlation between PEDs and the associated reported airplane anomalies".
That Boeing article is cautious in what it says.
But it is not hysterical.
Oct 12th, 2008 | 12:55 PM
#36
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I didn't see how the NZ incidents (laptop and mouse) were followed up. But the Boeing report was unequivocal:
"A passenger’s palmtop computer was reported to cause the airplane to initiate a shallow bank turn. One minute after turning the PED off, the airplane returned to "on course." When the unit was brought to the flight deck, <b>the flight crew noticed a strong correlation by turning the unit back on and watching the anomaly return, then turning the unit off and watching the anomaly stop</b>."
Not convinced, eh? I hope your family isn't on the flight that proves you're wrong.
"A passenger’s palmtop computer was reported to cause the airplane to initiate a shallow bank turn. One minute after turning the PED off, the airplane returned to "on course." When the unit was brought to the flight deck, <b>the flight crew noticed a strong correlation by turning the unit back on and watching the anomaly return, then turning the unit off and watching the anomaly stop</b>."
Not convinced, eh? I hope your family isn't on the flight that proves you're wrong.
Oct 12th, 2008 | 01:49 PM
#37
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