MRC_Hans
Penultimate Amazing
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- Aug 28, 2002
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It is mostly due to fear of intereference. Consider a modern plane shock full of essential electronics, and then imagine a dozen 2watt centimetre-wave transmitters operating inside!
But I have to concede that the same argument was also used at hospitals here, but later it expired that they had a contract with the phone company for payphones on the premises!
Anyhow, I think you will find that the coverage at 30.000 ft. is erratic at best.
Hans
But I have to concede that the same argument was also used at hospitals here, but later it expired that they had a contract with the phone company for payphones on the premises!
Anyhow, I think you will find that the coverage at 30.000 ft. is erratic at best.
Hans
Funny you should ask...
Found this report on Slashdot yesterday:
http://www.caa.co.uk/caanews/caanews.asp?nid=669
Found this report on Slashdot yesterday:
http://www.caa.co.uk/caanews/caanews.asp?nid=669
Crossbow
Seeking Honesty and Sanity
dwb said:Why do they ask you to turn off cell phones when you're on a commercial flight? Is there any science behind it (signal interference, etc.) or is it just a control mechanism?
Inquiring minds want to know.
Aren't you a pilot dwb? You know how conservative the FAA is regarding airplanes, and since there have not been extensive studies of cell phones and airplanes, the FAA takes the cautious approach and forbids them.
They have not lost a plane to a cell phone yet, and until they can prove that cell phones (or portable computers, or hand-held video games, etc.) are harmless, then they will not allow them to be used during the critical phase of flight (landing, takeoff, and below 10,000' MSL).
I mean, gee whiz, it took one company something like five years and three million dollars just to get a new four-clyinder engine approved.
okay, commercial aircraft tend to have many complicated avionics and senor systems on board, and as that .uk article suggests, signals emitted from cell phones can apparently affect such equipment.
Anyone have any specifics? "Navigation and communication" equipment is affected, what does that mean? If I have my cell phone on flying at 3000' AGL and I'm tracking a VOR, is my instrument going to read incorrectly? Will my GPS display my missed calls?
I don't actually have a cell phone at this time, it was just something I was thinking about. Crossbow, you're right that the FAA prefers to err on the side of caution (albeit too much sometimes), but it does seem like there's evidence in favor of maintaining the ban on cell phones during commercial flight.
Interesting indeed...
Anyone have any specifics? "Navigation and communication" equipment is affected, what does that mean? If I have my cell phone on flying at 3000' AGL and I'm tracking a VOR, is my instrument going to read incorrectly? Will my GPS display my missed calls?
I don't actually have a cell phone at this time, it was just something I was thinking about. Crossbow, you're right that the FAA prefers to err on the side of caution (albeit too much sometimes), but it does seem like there's evidence in favor of maintaining the ban on cell phones during commercial flight.
Interesting indeed...
Crossbow
Seeking Honesty and Sanity
Re: Re: Re: Cell phones on planes
Andonyx:
I would submit that the study you posted does argue against your point.
To be breif, the study says:
Although the equipment demonstrated a satisfactory margin above the original certification criteria for interference susceptibility, that margin was not sufficient to protect against potential cellphone interference under worst-case conditions.
So the only problem they ran into related to "worst-case conditions"
The following anomalies were seen at interference levels above 30 volts/metre,a level that can be produced by a cellphone operating at maximum power and located 30cms from the victim equipment or its wiring harness.
As I see it, this is the punch-line:
If one is using a maximum power cell phone,
while holding it 12 inches or less from the navigation/avionics equipment,
during worst-case conditions (something like an night IFR landing with cross-winds)
Then there could be a problem.
Therefore, the rule will continue to be implemented.
While they cannot be faulted for a lack of concern for avitation safety, but I must ask, have you ever seen someone make a cell phone call while holding the phone one foot from the avionics/navigation equipment in a commercial plane? I have not, and I fly small planes where the cockpit is quite small and I have seen several people use cell phones and the phones have not caused any problems (and I have been watching for them). In fact, due to new rules regarding cockpit security aboard commercial flights, such a thing will probably never happen (and I really doubt that it ever did to begin with).
I hope this helps!
Andonyx said:
Andonyx:
I would submit that the study you posted does argue against your point.
To be breif, the study says:
Although the equipment demonstrated a satisfactory margin above the original certification criteria for interference susceptibility, that margin was not sufficient to protect against potential cellphone interference under worst-case conditions.
So the only problem they ran into related to "worst-case conditions"
The following anomalies were seen at interference levels above 30 volts/metre,a level that can be produced by a cellphone operating at maximum power and located 30cms from the victim equipment or its wiring harness.
As I see it, this is the punch-line:
If one is using a maximum power cell phone,
while holding it 12 inches or less from the navigation/avionics equipment,
during worst-case conditions (something like an night IFR landing with cross-winds)
Then there could be a problem.
Therefore, the rule will continue to be implemented.
While they cannot be faulted for a lack of concern for avitation safety, but I must ask, have you ever seen someone make a cell phone call while holding the phone one foot from the avionics/navigation equipment in a commercial plane? I have not, and I fly small planes where the cockpit is quite small and I have seen several people use cell phones and the phones have not caused any problems (and I have been watching for them). In fact, due to new rules regarding cockpit security aboard commercial flights, such a thing will probably never happen (and I really doubt that it ever did to begin with).
I hope this helps!
Crossbow
Seeking Honesty and Sanity
Re: Re: Re: Re: Re: Cell phones on planes
Sorry about that Andonyx!
I thought you were trying to say that the study showed why the ban should be continued.
My bad!
Andonyx said:
Sorry about that Andonyx!
I thought you were trying to say that the study showed why the ban should be continued.
My bad!
Shouldn't we consider the threat to the cellphone infrastructure, as well as the threat to the plane? On the ground, a cell phone is normally within range of a few (say 1 to 6) masts, but at a height of several thousand feet, it might be transmitting to hundreds of masts simultaneously. This could make the cellphone system very confused. Maybe if everyone tried to use mobiles while in planes, the phone system would collapse.
ceptimus.
ceptimus.
Wally
Thinker
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- Jan 12, 2003
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- 229
ceptimus said:
As someone who is a pilot and works in the cellular industry, this is the greater concern. It drives the cellular infrastructure nuts to see the same esn show up on multiple widely separated sites. Even if the FAA didn’t forbid the use your phone wouldn’t work very well from a plane at cruising altitudes.
Jim
Having once worked for a company that made avionics, I know that the aircraft is an extremely noisy environment electrically. We occassionally had perfectly good gear that just would not work when mounted in specific planes even though an identical unit worked fine mounted in the same plane. I don't know if it is still true, but it used to be accepted practice to save weight by using the frame/skin of the aircraft for signal return/ground lines to save on the weight of wire. That increases the noise considerably. Adding additional noise from consumer electronics can only make things worse.
On the other hand, we know from the ill fated flights on 9/11 that cell phones do work, just fine, on aircraft (though not at normal crusing altitude). It has always amazed me that the cell phone system is able to work with fast moving phones high above a network designed for slow, land bound phones...
On the other hand, we know from the ill fated flights on 9/11 that cell phones do work, just fine, on aircraft (though not at normal crusing altitude). It has always amazed me that the cell phone system is able to work with fast moving phones high above a network designed for slow, land bound phones...
OK, so does this mean the hospitals really don't need you to turn off your cell phone???? I was in the hospital and waiting forever for the doctor in the emergency room with my child. I decided to make a few calls to have someone pick up my other kids, etc...
Boy, I was told I could have caused someone being treated for a heart attack to DIE! The nurse acted like I was trying to kill people.
I also remember being told by the cable people that if someone steals cable it can interfere with ambulance and police calls (????)
Boy, I was told I could have caused someone being treated for a heart attack to DIE! The nurse acted like I was trying to kill people.
I also remember being told by the cable people that if someone steals cable it can interfere with ambulance and police calls (????)
This issue has been discussed on aviation forums for some time. See, e.g. www.anywheremap.com.
A few points to consider...
First, commercial a/c do not have magic instruments. They use VOR (an obsolete ground based system roughly on radio frequencies), ILS (instrument landing system, sorta like VOR frequencies -- hundreds of megahz), and INS (inertial system for long routes like transatlantic). GPS is seen in newer installations. They also talk to controllers, on AM radio on the aircraft band, hundreds of mhz.
I have witnessed certain cell phones making noise and interference on aircraft radios. No big deal, but you could hear some static from the phone.
Most passengers don't really turn off their phones. They may not use them (reception is spotty) but they are often 'on'. So when they get in range of a cell, they may make some noise.
None of this has, to anyone's knowledge, resulted in any unsafe situations in flight.
The case against "other" electronics, like computers, is nonexistent. No one has demonstrated any interference from these things.
Cell phones may contribute to safety, as we saw in the PA 911 mishap.
A few points to consider...
First, commercial a/c do not have magic instruments. They use VOR (an obsolete ground based system roughly on radio frequencies), ILS (instrument landing system, sorta like VOR frequencies -- hundreds of megahz), and INS (inertial system for long routes like transatlantic). GPS is seen in newer installations. They also talk to controllers, on AM radio on the aircraft band, hundreds of mhz.
I have witnessed certain cell phones making noise and interference on aircraft radios. No big deal, but you could hear some static from the phone.
Most passengers don't really turn off their phones. They may not use them (reception is spotty) but they are often 'on'. So when they get in range of a cell, they may make some noise.
None of this has, to anyone's knowledge, resulted in any unsafe situations in flight.
The case against "other" electronics, like computers, is nonexistent. No one has demonstrated any interference from these things.
Cell phones may contribute to safety, as we saw in the PA 911 mishap.
Boy, I was told I could have caused someone being treated for a heart attack to DIE! The nurse acted like I was trying to kill people. I also remember being told by the cable people that if someone steals cable it can interfere with ambulance and police calls (????)
I don't know about the cell phone in the ER, but hospital rules are notorious for falling on the far side of paranoid. As for the cable signals, I work as a technician in the cable industry and know more about that. The short answer is: no, stealing cable won't interfere with ambulance or police radio. It can and often does, however, interfere with the overall quality of the cable signal. An improperly terminated or shielded cable on the system acts like an antenna and allows RFI to get into the system, messing up the clean signal your television needs. That means messed up video and audio coming out of your TV, and the poor cable technician has to locate the idiot who broke into the cable drop.
I don't know about the cell phone in the ER, but hospital rules are notorious for falling on the far side of paranoid. As for the cable signals, I work as a technician in the cable industry and know more about that. The short answer is: no, stealing cable won't interfere with ambulance or police radio. It can and often does, however, interfere with the overall quality of the cable signal. An improperly terminated or shielded cable on the system acts like an antenna and allows RFI to get into the system, messing up the clean signal your television needs. That means messed up video and audio coming out of your TV, and the poor cable technician has to locate the idiot who broke into the cable drop.
VOR is obsolete? Could have fooled me. VOR is one of the best ways to navigate, becuase it's proven and reliable, not to mention fairly easy to use. One should never rely on one method of navigation. At any given time, I can be using VOR, GPS, pilotage and dead reckoning on a VFR flight to determine my position.NWilner said:
To those that don't know, VOR stands for VHF Omnidirectional Range. It's a navigation system based on VOR stations all over the country. Many "electronic highways" have been mapped using VOR, so you can get from just about any point A to just about any point B by following known headings.
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kittynh said:
Challenge them or anyone to find even one case of someone in prison because they murdered someone by using their cell phone.
-Who
Ove
Master Poster
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Not casting much more light on this matter but i can tell you that our (Bang & Olufsen) EMC folks are reporting some disturbance from cell phones but hey, isn't this a situation where you really really ned to be "better safe than sorry"?
I mean, would you like to be in the one flight that discovered that a cell phone could indeed disturb the automatic pilot? Or the ILS system, or the Nav system so you ended up in Alaska in stead of Washington?
(Warning rant coming) It seem to me that some people are becoming obsessed with their cell phones. They seem to forget that such a thing can be turned off. You hear those things in restaurants, bars, theaters, stadiums etc. We are not as far as you american's but it's coming. Recently i observed one parent chatting away while watching his child take part in the scool play.
TURN THE BLASTED THINGS OF.
(Rant over)
I mean, would you like to be in the one flight that discovered that a cell phone could indeed disturb the automatic pilot? Or the ILS system, or the Nav system so you ended up in Alaska in stead of Washington?
(Warning rant coming) It seem to me that some people are becoming obsessed with their cell phones. They seem to forget that such a thing can be turned off. You hear those things in restaurants, bars, theaters, stadiums etc. We are not as far as you american's but it's coming. Recently i observed one parent chatting away while watching his child take part in the scool play.
TURN THE BLASTED THINGS OF. (Rant over)