Disconnected: Attention Passengers it's perfectly safe to use your cellphones [telecom]

With more than 28,000 commercial flights in the skies over the United States every day, there are probably few sentences in the English language that are spoken more often and insistently than this: "Please turn off all electronic devices".

Asking why passengers must turn off their mobile phones on airplanes seems like an odd question. Because, with a sentence said so often there simply must be a reason for it. Or - is there not?

Flight attendants are required to make their preflight safety announcement by the Federal Communications Commission because of potential interference to the aircraft's navigation and communication systems. Perhaps this seems like a no-brainer: turning off your cellphone inside a piece of technology as sensitive as an airplane. In our civilized times, there are only a few things imaginable which more likely lead to direct physical conflict with the person in the seat next to you than turning on your cellphone during takeoff and nonchalantly calling your hairdresser to reschedule that appointment next Wednesday. In Great Britain, a 28-year-old oil worker was sentenced to 12 months in prison in 1999 for refusing to switch off his cellphone on a flight from Madrid to Manchester. He was convicted of recklessly and negligently endangering an aircraft.

Yet with people losing their freedom over the rule, it may come as a bit of a surprise that scientific studies have never actually proven a serious risk associated with the use of mobile phones on airplanes. In the late 1990s, when cellphones and mobile computers became mainstream, Boeing received reports from concerned pilots who had experienced system failures and suggested the problems may have been caused by laptops and phones the cabin crew had seen passengers using in-flight. Boeing actually bought the equipment from the passengers but was unable [to] reproduce any of the problems, concluding it had not been able to find a definite correlation between passenger-carried portable electronic devices and the associated reported airplane anomalies.

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Reply to
joeofseattle
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No. No. No. Sigh. Typical garbage that passes for reporting these days. The FCC has zero authority over what flight attendents do or say on board the aircraft. The FCC does regulate radio devices and can specify that certain devices only be used on the ground, but it would be up to the FCC to figure out if someone were violating that rule and taking any action against the user.

The FAA (which has the authority over electronics in the cabin, not the FCC) operates on a "prove it's safe" model. Either the manufacturer or the operator has to prove beyond a shadow of a doubt that there won't be any interference. Furthermore, that has to be done on every model aircraft, inlcuding the ones that were designed before cell phones were a gleam in anyone's eye.

So far, the only companies willing to underwrite the costs of those studies are the ones putting picocells inside the aircraft cabin, which also deal with the FCC restrictions on cell use at altitude.

Reply to
Robert Neville

See

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for additional research.

Jason

Reply to
Jason

Reply to
Jason

What I've been doing for awhile now is copy'n'pasting to Emacs which reveals the "quoted-printed" crapola as "\nnn" which, when compared to the original article, can be quickly substituted across the entire article and not incur "The Wrath of Bill". :-)

For those unaware, Emacs is available for Windows, is available for Cygwin under Windows, and, of course, is available for all Linux and UNIX systems. I've been using it since the mid-1970s and one copy of its manual handed to me by RMS himself in John McCarthy's office at Stanford can be seen here which I scanned years ago:

210p, 9MB

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Oh, well, if you use The-One-True-Editor, I'll cut you slack.

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Reply to
Thad Floryan

I heard that the reason they don't want you to use mobile phones in airplanes is because you might bring up several cell sites at once. Don't know how true that is.

About 6 years ago, I was visiting my mother in a hospital. Lots of electronic monitoring equipment all around, and signs telling you to turn off the cell phone. Her physician used a cell phone while in mother's room. I questioned him, he said that cell phones were not a problem any more.

Three years ago, I had heart-bypass surgery. While still in intensive care, I was permitted to use a cell phone from my bed, even though I was wired up with heart-monitoring probes and a portable unit which transmitted my heart beat to a central monitoring room.

On the other hand, they would not allow me to plug the charger for the phone into the wall socket because the electrician had not approved the device. :-( My wife had to carry my phone out to her car to charge it for me.

Dick

***** Moderator's Note *****

Isn't it funny, how anal retentives of all stripes insist on having revenge when anyone proves them wrong. When their bosses tell them that Goldstein's agents have been here and we're at war with East Asia, they get really busy thinking up ways to irritate those that they used to be able to order around.

Bill Horne Moderator

Reply to
Richard

I have to say this was an awfully stupid article.

The problem with using cell phones in the air is if you're up at umpteen thousand feet, your phone may be visible to a hundred different cell sites, causing overload as the sites try to figure out which one you should talk to, and frequent site switches as the plane moves.

The airlines like Ryanair that allow mobile phone use in the plane have a microcell in the plane. The microcell's signal is stronger than any ground signal so the phones on the plane all register with it, and it can tell the phones to turn down the transmit power so the ground stations can't even see them. The microcell uses some other scheme to communicate with the ground.

All the airlines I know of with microcells are in Europe. I wonder how much of that is bureaucratic and how much is technical. All European cellphones are GSM, so a 900/1800 GSM microcell will talk to all of them. In the US you need 850/1900 GSM for AT&T and T-Mobile,

850/1900 CDMA for Verizon and Sprint, and iDEN for Nextel. That's a much more complex microcell.

R's, John

Reply to
John Levine

On Sun, 24 Oct 2010 20:26:57 -0600, Robert Neville wrote: ..........

.......... I think that the title of that old Dead Kennedy's album sums up the attitude of people asking why they cannot use their phones etc on flights:

"Give me convenience or give me death"

Sort of prescient, really......

How any media outlet can publish that "It's perfectly safe to use your cellphones" without proving beyond doubt the "perfection" of that safety claim is so far beyond gross irresponsibility it should be criminal.

-- Regards, David.

David Clayton Melbourne, Victoria, Australia. Knowledge is a measure of how many answers you have, intelligence is a measure of how many questions you have.

Reply to
David Clayton

And as I posted back in April, the NASA document mentioned in that IEEE Spectrum article appears to be this one:

"Personal Electronic Devices and Their Interference with Aircraft Systems"

Reply to
Thad Floryan

On Sun, 24 Oct 2010 20:10:57 -0400, snipped-for-privacy@yahoo.com said in Message-ID: :

No, no, no. The FCC does not require any such thing. The FCC forbids the use of cellphones (not all electronic devices) aboard aircraft because of potential interference to cellular systems on the ground.

The FAA, on the other hand, allows (but does not require) airlines to require turning off electronic devices that the aircraft wants turned off because of the potential for interference with avionics. The airline gets to decide which devices can and cannot be operated during various segments of the flight and can enforce that decision because the FAA backs it up.

A couple of years ago, the FCC considered doing away with its rule against cellphone use while airborne. There were very few commenters who favored the elimination of this rule, but there were innumerable opposing comments, including thousands from flight attendants. Some of the comments focused on interference to terrestrial cellular systems, some on potential interference to aircraft systems, but the overwhelming opposition was based on how damn annoying it would be to have people jabbering away in loud voices in an enclosed space. The FCC terminated the rulemaking.

I'm not sure I understand whether the reckless and negligent endangerment of which he was convicted based on potential physical conflict, or on the belief that there might be interference to aircraft electronics?

There were some studies conducted in England a few years ago that showed some interference to aircraft systems from GSM phones, but the principal conclusion was that more study was needed.

Reply to
Michael D. Sullivan

I have heard from so many "experts" that I don't know what to believe any more.

My college roommate's dad was an airline pilot. He continually had a problem during major sports events such as The World's Series, March Madness, hockey playoffs, etc. A passenger would fire up a portable radio trying to tune in the game. He knew it was happening because his instruments would wobble. I've also have had pilots tell me it's a bunch of hooey and my roommate's dad didn't know what he was talking about.

Experts I've read claim the problem is a cell phone at such an altitude would light up too many cell towers and the towers couldn't handle the hand offs of such a fast moving phone. Others say this is nonsense and the plane would have to be moving close to the speed of light for any of that to be an issue.

Personally I wouldn't want to sit anywhere near someone using the cell phone on a plane. It was irritating enough when they had the phones in planes. I was not upset to see those go. I've been traveling a lot lately and it amazes me how people immediately fire up their phones and start dialing as soon as the wheels hit the ground. Is it that necessary to be that connected?

My son was born at Holmes Regional Medical Center in Florida. There were "no cell phones" signs everywhere suggesting using one would kill patients connected to life support and monitors. Yet the county's 800 MHz trunked radios didn't cause a problem nor did the staff's cell phones. I suspect the real issue was the surcharge they collected when the phone in the room was used and perhaps money they collected from the pay phones scattered throughout the hospital.

John

Reply to
John Mayson

On Mon, 25 Oct 2010 04:08:56 +0000, John Levine wrote: .........

......... And because the microcell is close to the handset, the handset only transmits a tiny amount of power compared to trying to reach a base station a great distance away, so the potential problem of localised EMI in the cabin potentially causing issues is massively reduced.

Of course the complete lack of understanding by the general nuff-nuff airline passenger of the difference between the two scenarios will not stop a lot of 'em trying to uses their phones on a non-microcell flight.

-- Regards, David.

David Clayton Melbourne, Victoria, Australia. Knowledge is a measure of how many answers you have, intelligence is a measure of how many questions you have.

Reply to
David Clayton

On Sun, 24 Oct 2010 20:33:06 -0700, Richard wrote: ..........

They are probably more of an annoyance to others with their ringing and inappropriate conversations - most patients don't have the option to move away.

As someone who used to work in a hospital environment, I am pretty sure that the known problem - from back in the 1990's - of EMI causing problems has been addressed by all medical equipment manufacturers over the last decade. If you ask any Medical Electronics department these days you should get a good idea of how "immune" the hardware now is to this sort of thing.

Yep, where I am located you see *every* power cable in a hospital these days tagged with a safety check and woe be on anyone who tries to plug something in without a tag.

-- Regards, David.

David Clayton Melbourne, Victoria, Australia. Knowledge is a measure of how many answers you have, intelligence is a measure of how many questions you have.

Reply to
David Clayton

Recently I visited someone in the hospital. I was surprised that the P.A. system was still frequently used to page doctors ("Dr Jones call

1234"). I would've thought by now that would've been replaced by beepers or cellphones. Indeed, a hospital I worked at 35 years ago was transitioning to beepers.

As an aside, back then the Bell System introduced a feature "meet me page" when an outside call wanted to talk to a doctor. The page operator put the caller on hold and paged the doctor to call a specific extension. When the doctor dialed the extension, he was directly connected to the outsider caller. This eliminated a cumbersome cord operation at the switchboard.

Regarding cell phones on airplanes, years ago they told us not to play our transistor radios as they'd interfere with equipment. The reason was that radios apparently retransmit the incoming signal internally as part of the superhyterdone circuit, and this tiny retransmission could interfere with navigation eqiupment. If this truly was a problem I don't know, but airlines did discourage radio playing.

Regarding cell phones in hospitals, perhaps back in the days of more powerful analog phones, especially 'bag phones', the stronger transmitted signal may have interfered with equipment. Or, there was a risk of interference and administration did not want to take the chance, especially with critical gear.

Reply to
Lisa or Jeff

Nonsense. If that were the standard, then aviation would not be permitted (or every flight would cost as much as a Space Shuttle launch). Do not doubt that the people who do aviation safety know very well that safety can never be guaranteed, and their job is to minimize the probability of catastrophic failure, knowing that the world is too unpredictable ever to get it to zero. I think they're pretty happy that commercial airlines are several orders of magnitude safer (per passenger-mile traveled) than automobiles. Engineering, like life, rarely gives guarantees.

-GAWollman

Reply to
Garrett Wollman

There are other issues at play here, especially with cellphones.

In the USA, cellphones using:

CDMA (Sprint, Verizon) can transmit at 0.2 to 0.75 Watts GSM (AT&T, T-Mobile) can transmit at up to 2 Watts

In the past 12 months here in comp.dcom.telecom we've read numerous articles illustrating (specifically) GSM interference.

Besides the clearly-known cases of GSM affecting hearing aids up to

100 feet (30m) and 10000s of anecdotes, there are reports in the New York Times of GSM phones turning-on several models of electronic stoves (Maytag, Samsung, etc.) with the attendant fire hazard; one of several such articles is here:

Yesterday an IEEE Spectrum article was cited and I followed up with the URL to a NASA article demonstrating how cellphones perturb air navigation systems; I had a "hmmmm" moment afterwards thinking that wasn't the article cited in the IEEE article. So I did a Google search and, WHOA!, I'm finding 100s of PDF articles by Lockheed-Martin, NASA, et al describing cellphone and WiFi interference to airplane navigation systems such as:

NASA/TP-2003-212446, Wireless Phone Threat Assessment and New Wireless Technology Concerns for Aircraft Navigation Radios Langley Research Center

NASA IVHM Project (2007) Aviation Safety Program, EMI Environmental Hazards for Commercial Aircraft

Lockheed-Martin, Electromagnetic Interference and Assessment of CDMA and GSM Wireless Phones to Aircraft Navigation Radios, research funded by the FAA William J. Hughes Technical Center and by NASA Aviation Safety Program (Single Aircraft Accident Prevention Project).

NASA/TM-2004-213010, Portable Wireless LAN Device and Two-Way Radio Threat Assessment for Aircraft VHF Communication Band Radio

DOT/FAA/AR-06/41 In-Flight Radio Frequency Spectrum Measurements of Commercial Aircraft Cabins

W911NF-07-R-0001-05, FY 2007 - FY 2011, Army Research Laboratory

and 100s, perhaps 1000s, more all summarizing that cellphones should NOT be used in aircraft.

There's no doubt in my mind now. And when the cellphone manuals, as mine do, contain statements they shouldn't be used by those wearing medical electronics (e.g., pacers, pacemakers, defibrillators, etc.) even though there's no legal requirement for them to do so, I don't see how anyone can continue to ignore the obvious: cellphones are not safe. Period.

Reply to
Thad Floryan

That's FM radio. Local oscillator on an FM receiver is apt to throw junk in the aviation band... you will see VOR errors when you have a cheap consumer radio that is leaking turned on nearby.

Cellphones aren't like FM radio.

The issue is altitude, not speed. Line of sight at 30,000 feet is a long way... with a 20 watt VHF radio you can talk halfway across the country. Likewise with an FM radio you can pick up stations from halfway across the country.

Needless to say your cellphone can see cells halfway across the country too, and vice-versa. And the systems do not handle this gracefully, at all.

About the only nice thing about commercial aviation is that people put their cellphones away.

--scott

Reply to
Scott Dorsey

I also had to use CPAP machine for sleep apnea. At one hospital (the one for the heart-bypass), they provided me their own breathing-asist machine. At another hospital, they had the electrician OK my own CPAP machine.

Reply to
Richard

I suspect that the main *practical* safety hazard of cellphones is damage to revenue.

Who paid the cost of the studies to prove that these are safe?

- Flashlights, including non-obvious LED lights on keyrings

- Electronic wristwatches (no, I'm not referring to watches with internet connectivity, or that sync to an atomic clock, just ones with batteries to power the timekeeping). These generally don't have an OFF switch.

- Passengers with pacemakers. These generally don't have an OFF switch.

- Passengers with other electronic medical gadgets, such as an insulin pump for diabetics, oxygen equipment with electronic flow regulators, or implanted electronic defibrillators (some of those defibrillators "phone home").

- "electronic" cigarettes

I realize you said *electronic* devices, but what idiot thought these were

*ever* safe to allow on an airplane, even by Wilbur Wright:

- Cigarettes (I don't care about the cancer risk, I'm worried about fires)

- Cigarette lighters (probably all forbidden now, but I don't think so 20 years ago).

- Passengers who smoke (and tend to smuggle in the above two).

- Guns (even in the hand of law enforcement officers only).

- Equipment to heat/cook food (fire hazard).

- Hot coffee (useful as a weapon, can accidentally injure nearby passengers).

- Utensils (choking hazard. Even plastic ones may be usable as a weapon).

- Conscious passengers (sometimes subject to "plane rage". Also occasionally spread dangerous plagues.)

Reply to
Gordon Burditt

Why not have no-phoning sections, the way they used to have no-smoking sections? It's a lot easier to block the spread of sound than smoke.

Reply to
John David Galt

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