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Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

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Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#31

Post by eli »

From the press release for a Carnegie Mellon study in 2006:

"We found that the risk posed by these portable devices is higher than previously believed," said Bill Strauss, who recently completed his Ph.D. in EPP at Carnegie Mellon. "These devices can disrupt normal operation of key cockpit instruments, especially Global Positioning System (GPS) receivers, which are increasingly vital for safe landings." Strauss is an expert in aircraft electromagnetic compatibility at the Naval Air Warfare Center in Patuxent River, Md.

http://www.cmu.edu/PR/releases06/060228_cellphone.html

It's true that no crashes have been positively linked to cell phone use, but it's also true that black box recorders don't measure RF interference so it would be difficult to do so.

edit: and here's a link to the whole paper http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-ai...

In one telling incident, a flight crew stated that a 30-degree navigation error was immediately corrected after a passenger turned off a DVD player and that the error reoccurred when the curious crew asked the passenger to switch the player on again.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#32

Post by count »

eli wrote: post #21
rakkhi wrote: post #16

Earlier quoted context omitted.

Thanks for the link, a few good quotes from there: Now this I can definately belive: "the report concludes that the primary reason for the ban on cell phone use in flight is that neither the FAA nor the FCC are willing to spend the money to perform conclusive safety tests. " God flight attendant observations? Thats the evidence that is reliable? How could you isolate for all the other factors? "However a few reports…

This is my point - are we still in 1984? No, but I'm pretty sure the point is that planes from 1984 are still in use.

The airframes might be, but they definitely have been upgraded/retrofitted with newer gear.

My favorite is the industrial, hardened switch for 'Internet Off' on Delta flights with onboard Wifi now (which I can't believe I can't find a picture of!).

If I can use WiFi on the plane while it's flying, why not while it's taking off and landing?

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#33

Post by run4yourlives »

bobds wrote: post #14
ax0n wrote: post #7

I find it hard to believe that a plane's avionics are sufficiently shielded to withstand a direct lightning strike, but one person's phone will crash the plane. I've heard other explanations, too, such as the fact that too many mobile towers are line-of-sight at the same time, and the effective ground speed means you'd hop towers far too often and it'd mess with the phone system. Multiplied times the number of mobile…

I find it hard to believe that my tiny MP3 player could be dangerous to the plane's avionics, yet I'm usually told I have to turn it off before takeoff.

That is because they want you to have all your senses (especially hearing so they can give you instructions) during take-off and landing; the most dangerous parts of any flight.

It has nothing to do with the MP3 players themselves.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#34

Post by gte910h »

eli wrote: post #21
rakkhi wrote: post #16

Earlier quoted context omitted.

Thanks for the link, a few good quotes from there: Now this I can definately belive: "the report concludes that the primary reason for the ban on cell phone use in flight is that neither the FAA nor the FCC are willing to spend the money to perform conclusive safety tests. " God flight attendant observations? Thats the evidence that is reliable? How could you isolate for all the other factors? "However a few reports…

This is my point - are we still in 1984? No, but I'm pretty sure the point is that planes from 1984 are still in use.

Not really.

Planes are removed from service, every internal bit is replaced every few years.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#36

Post by mquander »

cryptoz wrote: post #28
rakkhi wrote: post #25

Earlier quoted context omitted.

Thanks for that I was really hoping that Mythbusters had tested it. "It was found that cell phone signals, specifically those in the 800-900 MHz range, did intefere with unshielded cockpit instrumentation. Because older aircraft with unshielded wiring can be affected, and because of the possible problems that may arise by having many airborne cell phones "seeing" multiple cell phone towers, the FCC (via enforcement t…

But that's the part I don't get; there's no "ban" at all! I can bring a bunch of phones on the plane and just not tell them about it. If they search my bags, they'll remove my 200ml of water citing "it's too dangerous" but they'll leave the cellphones alone. That's not much of a "ban". So I still disagree that phones could interfere in any meaningful way with any aircraft's systems.

That is a foolish conclusion.

Firstly, if the TSA searches your bags and actually finds a "bunch" of cell phones, I bet that they will find an excuse to hassle you about it.

Secondly, your own example shows how shoddy this reasoning is; the TSA is not rational* about what they confiscate and what they don't -- your water isn't dangerous, and they took it, so why would you trust their judgment on cell phones?

Thirdly, the cell phone industry moves much faster than the airline security industry, so it's (vaguely, remotely) possible that some new phone released yesterday is dangerous, whereas old models aren't; the airlines wouldn't know the difference. One could say the same for almost all consumer electronics. So it would be hard to ban "bad" electronic devices and allow "OK" ones, and probably not worthwhile. Banning them all is an option, but just because it's a risk doesn't mean it's enough of a risk to be worth addressing.

*At least, they aren't rationally trying to prevent planes from being hijacked or interfered with; maybe they are doing a good job at other things, like making people feel warm fuzzies about security.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#37

Post by hcho »

cryptoz wrote: post #22
hcho wrote: post #5

Leave your phone near a CRT screen or loudspeaker, observe the noise right before you recieve a call. The rest is statistics and probability. What's the probability of interference causing a fatal misreading in aircraft's sensor? Too small. What's the number of flights world wide? Too big. We would see a number of accidents if everyone kept their phones on all the time. As a death is one too many, it warrants the ban…

I disagree. The airlines claim the risk of death from my water bottle is too high to allow me to bring the water on the plane. Fine. However, I'm allowed to bring 100 cellphones in a backpack. They don't care about that, except to politely ask me to turn them off. If there was a remote chance of a cellphone causing a crash - more chance than a bottle with water in it - then they would ban cellphones in flight. It's v…

The water bottle thing is not airlines' doing as far as I know. It's to do with your countries national security authority.

Emirates allows mobile phones on some of their flights.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#38

Post by artmageddon »

This is strictly anecdotal evidence, but I'll throw in my 2 cents here. I have a private pilot certificate and am working toward an instrument rating right now, which involves being in continuous contact with air traffic control, flying in low / zero visibility conditions, and relying on aircraft instruments to guide me on landings.

On numerous(if not all), I've had my iPhone with me, switched on and even in my lap at times(to use the stopwatch). Occasionally I would keep it in airplane mode on extended flights, but only to conserve battery life. Despite incoming calls and SMSs during these flights, not once have any of the instruments been affected by the phone.

We can all agree that a four-seater Cessna and 767 are very different, but for nav/comm they all use the same instrument systems. I would find it very hard to believe that a larger aircraft wouldn't have more shielding / protection than a simple Cessna with a phone that's just two feet away.

One more thought: Federal Aviation Regulation 121.306 states that no portable electronic devices are allowed except for: portable voice recorders, hearing aids, heart pacemakers, and electric shavers. How are the first and last any different from a phone in airplane mode?

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#39

Post by hcho »

count wrote: post #32
eli wrote: post #21

Earlier quoted context omitted.

This is my point - are we still in 1984? No, but I'm pretty sure the point is that planes from 1984 are still in use.

The airframes might be, but they definitely have been upgraded/retrofitted with newer gear. My favorite is the industrial, hardened switch for 'Internet Off' on Delta flights with onboard Wifi now (which I can't believe I can't find a picture of!). If I can use WiFi on the plane while it's flying, why not while it's taking off and landing?

Because if something goes wrong the pilots have a lot more of time for a corrective action during flight. Not so much during take off and landing.

Re: Ask HN: Are mobile phones on a plane taking off or landing really dangerous?

#40

Post by eggnet »

run4yourlives wrote: post #33
bobds wrote: post #14

Earlier quoted context omitted.

I find it hard to believe that my tiny MP3 player could be dangerous to the plane's avionics, yet I'm usually told I have to turn it off before takeoff.

That is because they want you to have all your senses (especially hearing so they can give you instructions) during take-off and landing; the most dangerous parts of any flight. It has nothing to do with the MP3 players themselves.

Nope. Why force people to turn off their kindles but not close their books?
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