No, they are banned because of concerns about interference with avionics.

Unfortunately for the FAA, this has been repeatedly demonstrated to be more or less impossible, leading to this sort of ridiculous post hoc rationalization.

Any sort of rule that singles out electronic devices ("anything with an on-off switch," as the steward will tell you) is inherently going to be ridiculous. The attention argument, or the flying debris argument, apply equally well to any number of allowed things (if anything, electronics tend to be lighter than the books they replace).

Ultimately, this was a rule that was made a long time ago, that has long since lost relevance. It should be abolished.

Airbus pilot here. Electronic interference in take off and landing is real. It is pretty common and can indeed be pretty dangerous. The fact is that a tablet or smartphone in flight mode is not an issue as aren´t devices that are not transmitting. The biggest problem (maybe the only one) is that when you approach the airport and reduce your speed and altitude, the cell phones begin to receive the signals from ground antennas and start trying to connect again with the maximum power(the airplane body dampens the signals), imagine this taking place with dozens of mobile phones at the same time. Also there is people who tries to call or send a message while in approach, making it worst.

While on cruise there is no signal with modern 3g, also you go too fast to lock any tower so you don´t get the interferences. With old analog cell phones it was pretty usual to maintain signal and talk even at 30k feet (they affected flux sensor of the compass though).

This heavy transmission from tens of phones at the same time may or may not cause radio communication interferences (the same one you hear when your phone is close to the car radio annoying but not lethal), system computers reboots or complete loss of flight computers (and this can be very scary in bad weather, heavy traffic airport and close to the ground). This has happened to me while in a landing in Paris, not something that I would recommend. Also a friend of mine had all the flight computers, alarms and lights going wild while trying to land at Madrid too. Usually is less dramatic than that, and only a computer or system resets, but you don´t know when or how you are going to face it and how bad will become.

The problem with flight modes is that a significant portion of passengers don´t know how to set it. Some of them don´t even know how to power off their phones, with the stewardess having do it 2 or 3 times each flight(improving lately, it seems people begin to know their devices).

Maybe with an 3g antenna inside the plane, all the signals could be kept at low levels and this way be able to avoid interferences to the flight equipment.

While this is valuable information, it is all anecdotal: you're assuming that the incidents you experienced were due to electronic devices, but the FAA has never tested this, so it's a single datapoint where we don't even know how many (if any) passengers had active devices.

If the FAA were serious about flight safety, surely they would be testing this to a scientifically acceptable standard. Then, once we have the data, and assuming that there is a problem, phone makers could introduce some kind of "do-not-send" code that planes can broadcast so that phones stay quiet during flight.

The FAA has announced plans for an industry working group: http://www.faa.gov/news/press_releases/news_story.cfm?newsId...

The difficulty lies in testing the airplanes in such a way that you cover _all_ potential devices, past present or future, with or without manufacturing defects. This is not an easy task.

You're approaching the question from the viewpoint of a passenger that _wants_ to use your device. So naturally you pull out the anecdote card and say that since you can't _prove_ it's caused by cell phones, then cell phones should be allowed.

Unfortunately, that's not how the FAA, airlines and pilots think. What they think is that if there is a _minute_ chance that turning off cell phones in flight critical phases can give even a _marginal_ improvement in instrument reliability, then it's worth it for them. (And if you don't like that, you can always get yourself your own plane, a PPL and do whatever you like.)

Likewise, if you're a doctor and some medical equipment (say a heart monitor) at the hospotal is technically capable of running Quake since it's using Linux, you still don't want to install Quake on it if there is just the slightest chance that doing so could cause the heart monitor to hiccup. If something fails, it's your job on the line.

So to put this in perspective, a bad person could crank up their phone and prevent all sorts of safety and assistance systems on a plane from working?

Then why ban a bottle of water?

So how come in a meeting room at a conference, with maybe 200 people actively using multiple wireless devices plus WiFi access points broadcasting, nobody's computers are affected? Are avionics really that sensitive to environmental RF interference?

Those devices are all transmitting at low power, usually to a WiFi / cell base station nearby. The issue here is when several devices are transmitting on high power at the same time. Also, a computer is a single shielded device with most data running on a single motherboard and a few cables. Avionics are well shielded, but the cables and antennas run the length of the airplane and there's a _lot_ of devices in a typical setup (ADF, VHF NAV/COM, GPS, TCAS/ADS-B to mention some, all of it duplicated for redundancy), so the chances of one of them being affected is a bit higher.

Thanks for taking the time to comment here. I'm curious of this is such a widespread problem, presumably organizations like the FAA and researchers would have survey data from pilots that demonstrate how widespread the problem is (I would think pilots unions in particular would advocate for such information). Are you aware of any systematic survey of pilots to assess how frequently this happens?

There are actually some studies conducted. Note that these are _suspected_ interference from personal electronic devices and also incidents with passengers unwilling to turn them off: http://asrs.arc.nasa.gov/docs/rpsts/ped.pdf

Of course, all of this is anecdotal so it won't fly here on HN. :)

The real difficulty is that when an instrument malfunctions, that can be for any number of reasons. It's not unusual for malfunctions to occur, which is why airplanes have redundant avionics. However, there seems to be a few instances where the interference stopped after a passenger turned off their devices.

Well in my experience, small incidents are quite common, maybe a pilot can experience 4 to 6 a month. The hard ones are quite rare (thankfully) something like 1 every 2 or 3 years, maybe less(for a pilot flying 900 hours/year). But this is far from hard data, more like pilot and engineering informal chat. There is maybe more than the cell phone factor here, other problems involved that are hard to detect like a sensor with a corrupted signal, a bad cable (some miles of them at a plane), a software bug. I don´t think there is an easy solution. Thankfully it is very rare that this happens in a delicate situation (like a cat III landing with 0 visibility), and even then you can go around and call the passengers to disconnect their cellphones. It is not like a terrorist can come with a super evil cell phone and kill everyone that easily. But is a safety concern none the less. I wouldn´t recommend that politicians legislate about this randomly.

First of all, how do you know phones are the cause of this?

And secondly, if this is true, then how come people are even allowed to board flights without their persons and bags being searched for electronics that are turned on? I've flown cross country while forgetting to turn off the phone in my pocket. If it's that dangerous, why am I allowed to do that?

Well as far as I know you are not allowed. But thankfully it is not enforced, if your phone is not visible nobody is not going to tell you anything. That doesn´t meen that somebody at the cockpit keeps trying to reset a computer with no results. We don´t know phones are the cause, there is no way to know that unless you analyze all the signals of all the data busses and check what is going on. Of course not all the malfunctions are due to the phones, but we have enough of them to tell you that phones have something to do with some specific failures we experience. How much? nobody knows.

If this is true (and I don't really believe it) then all electronic devices should be banned from the cabin and carried in the checked luggage AND flight critical systems should be designed to be robust against such interference in case there is a terrorist attack using a hidden electronic device designed to operate at many times the power.

You didn´t really read the post do you?

I did, if you really think 3G phones en-masse trying to connect at maximum towers is the cause of computer crashes that you as a pilot describe as scary then someone setting out to do harm could design a unit that is easily hidden and for a short time could produce a much greater interfering signal.

There are two real possibilities:

1) Interference is not a real danger and not the cause of the issues you have on occasions experienced.

2) Interference from mobile phones is a genuine danger to aircraft systems.

If (1) is true interference is not a valid reason to ban electronic devices.

If (2) is true the current safeguards aren't high enough and the protection should be greater. If passenger jets are vulnerable to interference from normal 3G phones then it is a potential form of terrorist attack to create massive amounts of interference at a critical point in the flight deliberately. Probably much easier than messing about with binary liquid bombs.

Edit: Note that I believe that case (1) is by far the most likely and that I think that 10-100 times normal power device would probably be feasible if you didn't care about battery life although it might make sense to hide it in a laptop and use a bigger antenna than keep it in a phone package.

Well I can not surely say what causes each failure (not even the manufacturers know for sure, that is why they make tests continuosly), of course not all the failures are due to phones. But saying that phone interference is not a possible danger to the integrity of the flight is quite bold, as I doubt that you have experienced a failure of that kind as a pilot or as a flight engineer. I also doubt that you know what can be the outcomes of a misguiding indication or or complete fail of a system. You are surely oversimplifying the matter. Planes are not data centers, they experience a great deal of vibrations, temperature changes, extreme humidity changes (from very dry to lots of condensation). All the circuits, cables, sensors computers, pipes, pumps, metal sheet, everything inside a plane will behave over time in strange ways that are not fully understood even today. A weakened electronic sys(with already corrupted signals) may not support the kind of troubles that a nominal one could do with ease.

The problem with your claim is that it doesn't pass even basic rational examination of the known physics involved. Radio waves from cell phones are only one source. The transmitter in most cell phones is around 0.3 watts. Loosely speaking, a cell tower transmits at around 10 watts per antenna. Radio stations transmit at wattages measured in the kilowatt range. HAM radio operators can transmit at 100 watts.

All of these signals are flying around the atmosphere all the time. Distance certainly plays a role in effective power at the point of reception, but a tiny 0.3 watt cell phone transmitter isn't bombarding the aircraft with any more RF than an FM transmitter that is miles away from the airport.

The reasoning just doesn't stand up.

The third option is: Cell phones can in remote circumstances cause interference, but seldom enough to warrant banning all electronic devices with the massive revenue loss that would ensue. Likewise people are still allowed to bring lithium batteries even if they pose a fire hazard with several documented in flight incidents.

In the real world, regulations are the result of trade-offs and not absolutes. It's just that the current trade-offs seem to err on the side of safety.

But what about the jobs of honest hard working Americans employed to enforce these rules? If we get rid of this pointless rule, what about all the other time wasting, petty, mindless rules and the workers employed to enforce them? Many of these workers have families and children, and no hope of any other gainful employment in these hard economic times. Who's going to stand up for them?

Or something.

Yeah, it does seem like this rule and a soda machine would pretty much remove the need of economy class flight attendants.

There are plenty of rules that require enforcement that are not petty or stupid: requiring seat belts during take off, landing, and turbulence, or enforcing no smoking policies.

I am reminded of the discussion here a while back about Airbnb and hotel regulation: some of New York's regulations governing hotels are stupid and petty...but others come out of a genuine desire for safety (like adequate fire escapes and sprinklers). Same with the FAA: some rules are outdated, and silly: planes should be able to cope with personal electronic devices...but others are to ensure previous disasters don't happen again.

I'm sure some airlines would happily have fewer cabin crew if the FAA would let them: yes, they can sell in-flight items, but that probably doesn't break even on the cost of employing them.

I always thought just letting flyers pick out their cold beverage at the gate before takeoff would replace flight attendants (domestic; international still serves food).

They still need to serve me drinks and peanuts...and sell me food and alcohol.

> The point of putting away devices for takeoff and landing is that they can go flying into people's faces if you hit a bad bump or the airplane has problems

That is definitely not the reason for the rule. It's a post-rationalization and a poor one. If that were the reason, books wouldn't be allowed out.

Speaking of post-rationalizations, one I heard from a flight attendant recently is: "it's not that they aren't safe, just just need your full attention during takeoff and landing."

> The point of putting away devices for takeoff and landing is that they can go flying into people's faces if you hit a bad bump or the airplane has problems… which is most likely to happen at the start or end of the flight.

Then we'd better ban books too, since if a heavy book goes flying, it can cause some nasty damage.

See, I'd rather be hit in the face with a heavy, hardback book (say, the complete Lord of the Rings) than the edge of an iPad, let alone a laptop. But maybe that's just me.

I'd rather be hit in the face with neither. But maybe that's just me.

Not to mention unbuckled babies.

> If the Senator wants to put her attention somewhere related to aviation, I would think there are more interesting issues surrounding airport security.

Battling the TSA is political suicide right now, by and large. Might as well make some positive change with the power you have, rather than fighting a battle you know you can't win. That's not to say that there won't be a time for the TSA to go away or dramatically change form, but I don't think that's now.

CMC doesn't have an election for another six years, I wouldn't say it's suicide. On the other hand, you're right that she's not going to spend political capital on something she knows isn't going to go anywhere.

Edit: To be clear, she could do it. She's on the Homeland Security committee. But she's a in a tough battleground state and it's she really has to pick her battles carefully

I disagree. The TSA is extremely unpopular and an attack on it could get a lot of positive press.

Yes. Given all the frustration with air travel these days, going after the TSA/FAA is definitely low hanging fruit for a politician. They don't have many friends.

I don't think that's true. The TSA is unpopular, but it's seen as a necessary evil by most Americans. The average person has thoroughly bought into the government's propaganda that security theater serves some functional purposes.

This is the problem with bad legislation. Once it's passed it can take 2 decades, which is quite a lot of a person's life, to change. We need governments that are a lot more responsive to bad policy, either through better use of data, to know exactly how the policy is doing in just a few short years, or through a much more fluid feedback system from the population - or both.

Politicians are also heavily influenced by money in politics right now, and I'm not even talking about lobbying, which I think is legalized bribery and that's a huge other problem. I'm talking about corporations being able to ramp up media campaigns against them, and make them look bad in the public's eye because of a position they've taken, that the corporations do not like. This is why many politicians are afraid to even go against certain policies, unless they are pretty sure many others feel the same way, and they have a chance of winning.

Maybe this problem would be ameliorated if there were short term limits, and they wouldn't have to worry about their "career in politics" as much, and would care much more about what impact they can have in the short time they are in Congress.

> We need governments that are a lot more responsive to bad policy

You say this like someone who doesn't know that everything they value the government doing, or not doing, can be cast as 'bad policy' by someone who owns a think tank.

> a much more fluid feedback system from the population

I think California's Proposition system is illustrative here. And, therefore, California's current budgetary crisis.

> Maybe this problem would be ameliorated if there were short term limits

Then the power would shift out of the hands of elected representatives and into the hands of unelected party bosses, because the elected officials wouldn't be able to develop the real-world experience needed to navigate the halls of power on their own.

I guess the point people are trying to make is that an e-reader weighs the same or less than a book but books don't have to be put away during takeoff or landing.

But I do agree, airport security hassles are more annoying these days than being told to turn off your cell phone for 15 minutes.

I was on a plane that had to make a very sudden emergency landing. There was no time for items to be anything but tucked into the back of the seat or beside you, before we had to duck our heads down. The main injuries sustained were from people who hadn't done up their seat belts or from shock/panic. There were a few newspapers and magazines floating around, the odd book and small camera too.

So if there is another emergency and potentially free-floating items are flying through the air within the cabin, I'm far happier being hit in the head by a paperback novel, than I am an e-reader. Let alone a mobile or laptop.

What about a hardcover version of LoTR? The point is that this explanation is a retconing of the original reason for this rule, which has nothing to do with free-floating items in the cabin.

Did that emergency occur during the short window after takeoff and before landing when electronic devices are not allowed?

> If the Senator wants to put her attention somewhere related to aviation, I would think there are more interesting issues surrounding airport security.

Wouldn't this useless regulation be a nice conversation starter in the right direction? It will establish a (moral) precedent that it's for politicians OK do get rid of rules that are "for safety" but actually aren't.