http://en.wikipedia.org/wiki/Rusty_bolt_effect

I figure that if cellphones actually mattered, the FAA would have long since required such devices in airplanes.

It's like building a house that can't stand rain.

When people say "X is possible", they mean "X has a non-negligible chance of happening in practice", and is therefore worth worrying about.

They do NOT mean "Prob(X) > 0". You're already on the wrong track if you're talking about mathematical proofs of "possibility" in engineering.

It's really, really, really small, with millions of successful flights done without problems. Yet accidents like those have happened, and have been prevented after that rule was put in place.

I was using mathematical proofs as an example of why in IT security, often times since you can't be sure, you do the proactive thing and don't run services exposed to the internet. If you have a database with credit card numbers, you don't let the DB listen for connections on a public IP, not because you think there is a security hole in the DB, but because you can't be sure there isn't.

Links please?

The rule you point to was put in place because evidence strongly supported the fact that distracted pilots are a hazard.

No such evidence (that I know of) exists for portable electronic devices, and I don't believe for a single second that Boeing would make an airplane susceptible to harm by cell phones.

If you want links to examples of PED interference, I've posted them elsewhere on this thread. All anecdotal of course, but there are enough examples that to say there's no chance if interference would imply a secret conspiracy amongst pilots to file false reports.

And again, you are misunderstanding the concern. It's not whether a cell phone can stop the airplane from working and make it fall out if the sky. It's whether, at a critical time such as during landing and takeoff, it may cause interference that can increase the pilots workload and contribute to an accident.

http://asrs.arc.nasa.gov/docs/rpsts/ped.pdf

I agree BUT you've got to remember that there are a ton of different devices in the world. You can't expect every flight attendant to know what the difference (visually) is between an iPhone and an iPod Touch is, let alone how to set every device to their equivalent "airplane mode."

Of all the rules I disagree with, this is the one that I understand the most.

> If they were actually that dangerous, we wouldn't be allowed to carry them on board.

My understanding (from a pilot friend of mine) that it is really about radio interference with the pilots' radios. Recall the older Edge (for ATT, whatever else for other providers) devices being put up near speakers and that sound made[0]. The rules are still there mainly to protect the pilots' ears from that noise and possibly dropping communication, though I don't know how possible that is. Yes, that isn't common place anymore now that radio frequencies have moved on but how is a flight attendant going to know the difference between an Edge device that causes interference and some 4G device that doesn't?

[0] http://www.youtube.com/watch?v=R0O1_FYzbjw

The case that I suspect worries them isn't the well-manufactured, brand-new device on a shiny new plane. It's the older, banged-to-hell, third-rate Chinese knockoff against the oldest avionics in service. The question they have to answer isn't, "Should it be fine?" but "Can we prove it will never cause a glitch at the worst possible moment on the most problematic flight of the 10,000,000 we have each year?"

I'm astounded at the arrogance of random people who are sure they know the answer to that based on zero data and a strong sense of entitlement.

[Edit for background:

The case against water is "Water is difficult to tell, by cursory visual inspection, from a binary explosive. We've never actually lost a plane to a binary explosive, but we know they were pretty serious about trying that, and we wargamed it out and it looks like one liter of binary explosive applied to the right part of the right airplane means we have a very bad day." ]

Its "distraction of pilot or minor technical disruption during a difficult landing at a moment that has become crucial because of other issues."

Al Qaeda can't afford to put terrorists with custom electronics on an appreciable fraction of our 10m flights a year hoping they get one of the 10 most vulnerable ones.

But those flights will have hundreds of electronic devices on them. Being 100% sure that there will be zero problems is tricky. And given that the tradeoff is, "people have to read a magazine for a few minutes" versus "fiery death for hundreds", I'm perfectly ok with them being conservative here.

I keep getting back to what was already said above: if there was any actual risk whatsoever, we wouldn't be allowed to carry them on in the first place.

I think we've seen that this is not a problem for the Powers that Be. It's not as if the TSA chairman ever has to fly coach.

and would probably be overkill

I'm certain that we've seen that this is not an obstacle for implementation by the government.

but the risk is still non-zero

(Shrug) Zero accidents out of tens of millions of flights in which you can be pretty sure that at least one passenger has left their phone on. Close enough to zero risk for me.

If you think anything that doesn't directly cause accidents aren't worth regulating, you don't truly appreciate why we have such good air safety.

Letting he pilots chit-chat when landing can't hurt either, right? Millions of successful flights before the sterile cockpit environment idea came about, would perhaps seem like close to zero risk for you, yet we are all safer now because of it.

By definition I take far more risk when flying a single-prop light aircraft, and I'm fine with that. What I don't expect is to be able to force that risk level on other people.

You can't run a civilization on the Precautionary Principle. You understand that, right? Most people understand that, but the TSA and (until now) FAA don't seem to.

And as mentioned elsewhere there had been reproducible incidents of interference reported, which was the initial reason for the ban.

While I have long maintained that the ban is most likely not necessary, I'd much rather have he FAA make that decision and wait a few years until they have done enough studies and collected enough data.

I agree that we can't run the entire civilization on a precautionary principle, but then again that's not what we're talking about. We're talking about 10-20 minutes of inconvenience during critical flight phases. And believe me I hate the beurocracy and often overreaching rules of the FAA (or EASA in my case), but again I appreciate that we would not have he current air safety record without it. In fact, the FAA is usually reactionary in that they usually only act when fatal accidents have happened. (Pilot and crew rest hour limits is one very recent example).

Shouldn't it be the other way around? Shouldn't the onus be on proving that there is no risk, not that there is?

It would have kept us confined to the caves, if not the trees.

Yes, clearly we should... um, do what?

What's your point, that you would be happier with a riskier aviation industry?

My point is that many of the things that annoy passengers don't have anything to do with quantifiable risk. Suggest reading some Feynman, specifically his essay on "Cargo cult science."

As I said, get a PPL

That wouldn't give me any special authority on the subject. These questions must be answered analytically, not with fearmongering from bureaucrats or anecdotes from pilots without RF engineering credentials.

I suggested getting a PPL to get rid of all those annoyances that commercial air transport impose on you to reduce their risk. There is even an experimental airplane category if you want to err on the risky side.

I agree that it has to be approached analytically, but since you can't prove a negative, in the end you have to make a risk assessment. I certainly don't agree with all of them, but there have been enough examples of fatal accidents when the FAA didn't do their job, that I'm happy that they are taking their time to, guess what, do the analytical work, before changing a regulation. As opposed to acting on a gut feeling about what would be safe.

Dude, if I said the sky was blue, you'd post a response to Hacker News insisting it was green.

I wonder how much power it takes to desense a GPS receiver, however.

Terrifyingly little, it turns out. Signals from the GPS constellation are about as 'bright' as a light bulb several thousand miles away, and the modulation format usable by civilian receivers is not exactly jam-resistant.

Thankfully there's no reason for a GPS antenna on an aircraft to look anywhere but straight up. It can be well-shielded against interference from within the cabin. Still, GPS interference is a real, reproducible and documented issue, unlike the cargo-cult science being discussed here.

If it was the case, this would be a complaint we hear from pilots every day. Think of how many people simply forget to turn off their cell phones...

I'd be willing to bet that most people don't bother to actually turn off devices / switch to airplane mode. On a flight last month I even watched a guy turn off the screen on his iPad when asked to shut it off, then as soon as the attendant walked away he turned it on again and continued to use it throughout take-off.

And although it is not a problem for a pilot in normal conditions, it could be a factor that complicates things for a pilot. If the visibility on a takeoff/landing is bad, there is traffic congestion, air traffic control is stretched to the limit you'd definitely don't want a faulty cell phone suddenly jamming an ILS approach system ;)

I'm sure it happens (the post a bit back about the guy's laptop that was broadcasting mic input due to wacky wiring is a great example), but I'm really dubious that it's significant enough to actually interfere with comms from a system designed to throw radio signals 200 miles.

Sometimes you hear interference from GSM phones because the TDMA time divisions are in the AF range, but that's really a function of the power envelope rather than the power of the transmitter. I don't even really count this because I've never seen a GSM phone interfere with a non-part-15 device. Radios have to reject nearby signals; noise well outside their frequency range is even easier to reject. (I've never heard anything like GSM interference while operating my HF radio, either, and I have a GSM phone.)

These are local nav systems, not FM stations that put kilowatts into the air.

Take an ILS (instrumental approach) frequency 108Mhz. Any piece of wire of around two feet (half dipole) can be a pretty effective antenna at that frequency. Say, headset cable + an output cascade of the amplifier self-excited at this frequency? Doesn't happen in real life, but still...

I am not sure how much effect this has, but it's something to keep in mind.

Call it the e-book equivalent to brown bagging a beer on the street.

I don't think flight attendants should be required to identify and evaluate each device and its capabilities. They are trying to keep planes flying safely and on-time.

Probably like most, I sensed (but didn't know for certain) that the rule might be overkill, but I don't think it's completely unreasonable and I assumed that someone must have seen some degree of at least theoretical risk, then traded that off against passengers reading a magazine or actually talking to a neighbor for a few minutes.

And, in any case, I certainly don't pin it on the flight attendants.

Something about that attitude of being irate or angry about it just comes off as entitled and bratty. Like, "how dare you pry me away from my precious device for a few minutes in the name of public safety".

Makes me think, "Wow. Get over yourself."

That's pretty funny. But, no. It wouldn't.