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Comment by bsg75 | Hacker News Reader

Curious - why are people so damn resistant to turning off their devices for takeoff and landing, given the chance it _might_ be safer?

Even in the absence of hard data, I would prefer to ensure all cockpit instruments work with minimal interference, than read another email or send another tweet. Then when data is available to make a conclusion as to the effect or lack thereof, informed decisions can be used to create procedures.

People are so attached to their devices that they take any inconvenience towards using them as some sort of rights violation.

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Because it isn't safer and the rule doesn't make sense. I don't like to follow arbitrary rules created by uninformed people, especially when they don't make sense and are inconvenient.

Are you an electrical engineer, or similarly educated in RF communications, and thus able to determine what is arbitrary?

I have been in tech for 29 years, and I am a licensed commercial pilot in both fixed wing and rotorcraft (but I don't work as a professional pilot.) I don't know what effect my iPhone would have on aircraft instruments, so I turn it off.

Pre-flight and in-flight procedures are based on what is known, and what helps to prevent problems from the unknown. The safety of flight is in part about not taking unnecessary risks. For example, if I have to visibility into a cloud (radar, instruments) I do not fly through a cloud.

I apply this logic to during the critical periods of takeoff and landing, if I am unsure a device that emits RF will affect my instruments, I shut it off. Inconvenience does not outweigh safety, even / especially if the effect on safety is unknown. The worst case scenario, although likely minor, is simple not worth the risk.

> Are you an electrical engineer, or similarly educated in RF communications, and thus able to determine what is arbitrary?

CpE here. The vast majority of communications links on planes use twisted-pair differential signaling [1], which is extremely resistant to RF interference.

I've also worked on test procedures for avionics equipment, and assure you that RF interference testing is a part of all test plans for such equipment. The types of interference we tested against were far more aggressive than those that any consumer electronics can emit.

Keep in mind that the FCC also aggressively regulates RF emissions from all consumer electronics devices. Testing against FCC regulations is an involved and expensive affair, and the vast majority of devices are forbidden from any powerful RF emissions.

> if I am unsure a device that emits RF will affect my instruments, I shut it off. Inconvenience does not outweigh safety, even / especially if the effect on safety is unknown. The worst case scenario, although likely minor, is simple not worth the risk.

If phones or other complex electronic devices truly can interfere with avionics, their presence should be forbidden in the passenger cabin. It wouldn't be hard to detect them during security screening.

I conjecture the reason that this hasn't happened is because the risk of such interference is a practical impossibility for the reasons stated above.

1. http://en.wikipedia.org/wiki/Differential_signaling

Thanks for some actual information (vs speculation, and paranoid resistance to authority).

That said, care to speculate why the prohibition on device use during takeoff / landing?

Speculation: legal liability ass covering. If they allow it and it ends up as the probable cause in a plane crash that kills x hundred people it's a major disaster and likely to lose everyone's involved jobs. If they continue with current policy it's a continued minor inconvenience that many people ignore anyway.

Payoff matrix is pretty much locked on status quo for now, maybe it will soften to "up to the airline but we advise against it" at some point and some of the smaller airlines will differentiate by allowing it and after a couple years the dam will burst.

It's because those are critical phases of flight, with an especially high workload on the pilots. This is also why small talk between pilots is disallowed during takeoffs and landings. If an instrument acts up in cruise, the pilots have a lot of time to figure things out, while an instrument acting during landing is much more likely to lead to dangerous situations.

It's rooted in a superficial theory of crowd psychology.

It doesn't really matter whether passengers obey the cabin crew in most situations, but the two you mention are exceptions. Particularly during landing, if some moron is dancing around in the aisle, she is likely to hurt herself or someone else. The airline is the only deep pocket in that situation, so it's considered very important that passengers submit at that time. The more random rules they can heap on (keep your windowshade up, keep all your items under the seat, no Gameboy-playing, etc.), the more cowed the passengers and the more rare the expensive injury lawsuit.

It's like those religions that really depend on their congregants' obeying to the point of never really thinking: all of those ban the consumption of alcohol.

Well that's an interesting and seemingly arbitrary characterization.

You see, I did not need to know what he said in order to know that the rule didn't make sense (although I do appreciate the info). There are a few problems with your default position of "minimize risk because we don't know". If you don't know, how is it different from the 13th floor being bad luck? Something bad might happen if you visit that floor. To minimize risk, we should just avoid it?

Generally, the burden of proof has to be on whoever makes a claim that something exists. The existence of the rule is essentially that claim. The creation of the rule was not backed by any particular study or data. You speak dismissively of what you perceive to be speculation, yet that is entirely what the rule is based on (you also said not being afraid of these ghosts is the paranoid behavior, but I digress).

To introduce a little logic - we know that this has more than likely been tested. The fact that it's a concern at all means it's a safe bet that experiments have been done. If said experiments found anything at all that causes danger to a flight, it defies reason that they would not implement a hard ban on the devices and screen for them. There would be penalties and fines. Instead, a polite attendant asks that they be turned off. Does this make sense to you? It tells me that they aren't very serious about it. There is no way that anything potentially dangerous would be trusted to "the honor system".

Once a rule is in place, it's difficult to change it, so it remains the default. Wireless signals are the modern day version of ghosts. They might cause cancer, they might crash planes, they might microwave your lunch. Of course, we have no reason to believe that they do any of these things - we just don't have a reason to believe that they don't. As a scientist, it is your duty to reject this invalid line of reasoning.

"If ... their presence should be forbidden in the passenger cabin"

It bears mentioning here that the FAA approves ipads in the cockpit itself as a replacement for flight charts[1]. And many airlines give their pilots ipads.

[1] http://en.wikipedia.org/wiki/Cockpit_iPads

You seem to be operating from the assumption that the rules actually mean anything and somehow the vast majority of flights are done with all electronics following the rules. This is laughable. I'm sure that every flight with more than 100 people has at least a dozen bits of electronics still fully powered on and transmitting.

Why do I think it's safe? Because rules don't control reality, only people's behaviors do. In reality, we fly with our electronics on every single large flight, and they are not crashing or experiencing any particular problems. The only reason the rules are still there is that nobody wants to run the risk of being the one who gets blamed for some problem, because after some crash or something, somebody else who labors under the delusion that the rules actually mean something will pin the blame on the electronic devices, falsely, and by extension, the one who lifted the rules.

That's it. That's the only thing keeping this rule in place. It sure isn't physics. I don't have to be an EE or anything else, we've run this experiments hundreds of thousands or millions of times already.

That said, your little planes may have their own issues and this experience may not apply to your plane. But we're talking commercial flights here.

There are two assumptions that people in these discussion make

1) If 30% of the passengers leave their devices on today, leaving 100% of the devices on won't cause any increase in problems, and

2) If something happens it's either a) nothing, or b) the airplane falls out of the sky.

The fact is that an airplane is an incredibly complex machine. Instrument failures happen all the time, and pilots deal with this (they have redundant instruments and alternate procedures they can follow). If some of these problems happen due to interference from electronic devices, that's pretty much impossible to verify.

>I don't know what effect my iPhone would have on aircraft instruments, so I turn it off.

And my buddy at work takes flying lessons from a pilot who leaves his on so he can check weather and use other cute apps. As do probably numerous other less-enlightened pilots. So where is the epidemic of anomalous readings?

If airlines really believed that use of electronics could bring down an aircraft then they would ban passengers from using them entirely. Allowing passengers to take them on the plane and simultaneously claiming they are extremely dangerous is simply confusing. The passengers guess that the risk is being exaggerated as a way to control them so they resist on principle rather than because they care very much about using the devices.

Seriously, how hard would it be to set up a rigorous test in an average airliner, noting what interference was detected, how much, and its objective effect on avionics?

That's why people are so resistant; the whole thing has the stench of unsubstantiated BS about it. Kinda like the TSA.

Well, it wouldn't necessarily be so hard to test a few devices on a plane.

But there are thousands of models of phones, tablets, wifi cards, 3g cards, bluetooth accessories, LTE/WiMax cards, gps devices, etc., etc., etc.

Then we get into the wide variety of planes in the air with varying amounts and types of avionics, radios, etc. And those systems are in different places in different planes.

And don't forget aftermarket alterations both in software and hardware (i.e. custom firmware, different batteries) to those devices.

So your test wouldn't be too hard, but the result it seems you want (i.e. a definitive answer on the safety of electronics use by passengers on aircraft) takes a hell of a lot more legwork.

They do perform those tests, but they can't account for all potential future electronics devices.

Likewise, you can test your database server for all known exploits and it might come up clean, but if you open your firewall you can still be hacked if someone later on finds a new exploit. A security minded person would ask you: "Was it _really_ necessary to open that port, of could you have inconvenienced your developers a little bit and made them use a VPN instead?"

Trust me, this isn't the only rule in aviation that seems stupid, but the mindset that results in rules like this has had a positive effect on aviation safety.

They do perform those tests, but they can't account for all potential future electronics devices.

So, our defense against potentially dangerous future electronics devices is a generic safety announcement at the beginning of the flight with only cursory verification that it was followed?

Yes. This is a trade-off. Do they search your hand luggage for air band radios? No, they don't. That's also a trade-off, even though you could certainly cause interference with one.

It's also logically inconsistent. Either the threat of interference and danger is great enough to warrant bag checks, or it is not, and this threat is overblown like every other "threat" in air travel nowadays.

Of course it's logically inconsistent, but this is the real world and trade-offs like these are made. Same with Lithium batteries, although there have been several confirmed cases of such batteries catching fire in flight they are still allowed. It's just not feasible to ban cell phones and laptops.

Likewise, airlines have a "clean cockpit" policy disallowing small talk during landings. Do they monitor the CVRs and fine pilots who break this rule? I don't think so. Will some pilots find the rule exessive and make exceptions? Maybe. But the rule still has an effect, and is in place because of previous accidents where distracted pilots have been a contributing factor.

While I think this rule about electronic devices might be too stringent, and that it will eventually change, I don't think the airlines have overblown it. Pilots will handle instrument failures gracefully in 99.99% of all cases, and then there's the fatal accident where some stupid malfunction caused the pilot to screw up (AF447, and many others before). Because they know this is a "numbers game", they try to minimize potential problems, even though they may not be able to eliminate them altogether.

Because I think it's bullshit (either superstition or a lie). "Might sometimes interfere in an undefined way with an unspecified device" is a non-falsifiable claim.

If somebody told me not to fart during takeoff and landing (because it might change trajectory of the plane — you never know…), then I'd still protest even though it _might_ be safer not to fart.

Phones are supposed to pass FCC EMI tests and I expect planes' electronics to be properly hardened/shielded from EMI even stronger than tiny consumer devices can produce.

Maybe everyone on the plane should pray that the equipment works properly, because it can't hurt!

The best argument I've heard is that its about distraction (EDIT: and in-cabin projectiles), and takeoff/landing are more prone to harsh landing situations.

That one is great. But books are fine, even if they weigh more than an ipad.

Curious - why are people so damn resistant to turning off their devices for takeoff and landing, given the chance it _might_ be safer?

The argument is similar to subjecting yourself to radiation in the off chance that it (scanner) might detect yourself as a terrorist.

And you are given an option to skip the scanner, in trade for a fondling.

Also this is not a security issue (one of persons with malicious intent). It is a safety issue, one of incompletely studied electronic effects.

Well, no, you're wrong about that. If there really were anything other than superstition supporting the thesis that personal electronics could realistically and predictably have a deleterious effect on avionics, then that would indeed be a security issue.

>incompletely studied electronic effects.

Are you an electrical engineer, or similarly educated in RF communications, and thus able to determine whether the EMI testing that's been done is incomplete?

Refusal to turn off electronics during takeoff and landing - the most passive aggressive form of terrorism ever.

Why are people resistant to obeying arbitrary rules based on unsubstantiated speculation? You got me there.

Because there are far more electronics in the plane than in any of my devices, and it's ridiculously easy to disable radio communication. Until they force me to turn off my device or provide me with a compelling reason that it could interfere with anything, I'm just going to write this request off as irrational luddism.

Flying on a plane is already far and away the most miserable way for me to travel, don't take away my goddamn ipod.

Because those devices help distract us from how awful the entire experience of flying is.

Not well enough in my experience. Nothing will make those half-human sized seats bearable.

And I would reiterate, this is during the brief period of takeoff and landing.

I've had a few "brief" takeoffs lasting more than 2 hours. I'm sure other people here have as well.

Maybe the book publishing lobby is behind it

Some people like to leave their device on precisely because "an authority" is telling them to turn it off.

Reminds me of how, as soon as a plane touches ground, people jump out of their seats and take their luggage… and then they stand around uncomfortably for ten minutes until they get to leave.

Because this is faith based "safety" and if there really is an issue, then it's a huge safety & security problem with avionics, not with personal portable electronics. A problem that ought to be addressed, rather than naively hoping for the best.

I think a better question is why are you so resistant to making a sacrifice to Zeus, god of lightning, on the off chance it __might__ be helpful? There's a lot more evidence for Zeus than there is for iPods bringing down airplanes. (Lightning bolts are real, but there has never been a documented incident of the latter thing.)

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