...because very few people do use such devices, because it's not permitted?

That said, I could quite easily do the easyJet 737 and A319 safety demonstration for you, the number of times I've seen it. I could probably even do the French version. But that's not true of most people, and most people won't even notice the differences between the two aircraft that might be worth noticing (number of exit doors, way of opening them, different way of putting on lifejackets[1]). And the rules need to be the same for everyone, else you can't enforce them.

[1] 737 tie round the front, A319/20/21 have clips. But more significantly, how many people notice that on a narrowbody you *must not* inflate your lifejacket in the aircraft (it'll get you stuck in the exit) while on a widebody you are sometimes told to inflate it on board (because the doors are wide enough)? That one is *really* significant, as a blocked exit door could mean death to many people stuck behind.

Neil

Ok so are we now all agreeing that the reason is all about attentiveness and not some sort of radio signal?

For non-transmitting devices I'd say it was 95% attentiveness and 5% possible interference (any electrical device *can* cause interference, but most don't to any significant level).

Neil

I've always been of the opinion that the rule exists only partially because of the possible dangers of RF interference with avionics. It has been tested here and there, just not comprehensively, and it seems that modern aircraft systems are pretty well shielded against interference from common phones and laptops.

Why is it that we are required to fasten our seatbelts during takeoff and landing? Why are all pax and flight crew required to be seated, and not in the lav, galley, or isle? Why must the seat backs and tray tables be put in the full upright and locked positions? Why must all carryons and loose articles be stowed securely under the seat or in the overhead?

It's because takeoff and landing have the most instances of actual maneuvers. Turns, banks, climbs, and dives are all routine parts of takeoff, ascent, descent, and landing, even when the air is perfectly still and there is no turbulence of any kind. Securing loose articles, and people, during these maneuvers, gives pax the highest possibility of escaping injury in the event of an incident, and prevents loose articles from flying around the cabin when the aircraft banks, rolls, or pitches.

I obey these rules, not because I'm a mindless lemming who always does what I'm told, but because I'm intelligent enough to see the very real risks associated with having loose articles in the cabin during takeoff and landing.

I also keep my seatbelt fastened whenever I'm seated during cruising flight, because you never know when sudden, unexpected turbulence might make the aircraft do a Ringgold's Pirouette and turn the cabin into a giant cocktail shaker.

With all the technological innovations these days, it's better to be safe than sorry

Wikipedia has this to say about it:

"...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. They have left this up to the airlines who do not see any return on investment made in paying for such tests."

If airlines charge extra to transport your bag or give you a glass of coke instead of the whole can everybody screams bloody murder. Just imagine what happens if airlines increase their ticket prices to cover the costs of testing consumer electronics for interference with flight systems, or for building a shielded compartment for eAddicts.

The costs would be pretty high, because the distance between a phone and the nearest cell tower will never be less than the altitude of the plane, i.e. a phone aboard a plane will always transmit at maximum power, whereas a phone on the ground will rarely need to do so.

Of course electromagnetic shielding can be done. Put some seats in a sealed compartment and charge pax in the new iClass-of-Faraday $100k o/w for the privilege of texting their girlfriends and a few extra minutes of laptop time between the ground and 10k ft.


It's reasonable to assume that statistical analysis by NASA and testing by IEEE is more reliable than the gut feeling of passengers who can't survive a few hours without their Blackberries, so let's look at the data.

The results of a NASA study on interference by cell phones and laptops:

These were incidents from 1986 to 1999. Since then the use of personal electronics has grown exponentially, so it's reasonable to assume that the number of incidents and their associated risks has grown accordingly.

From the IEEE:

Banning cell phones became popular after the Crossair crash in 2000 which killed ten people. The autopilot malfunctioned at the same time one passenger received a call and another one received an SMS. That's no conclusive evidence, but it's a good reason to be safe rather than sorry and to put the burden of proof on those who want to use their phones and laptops instead of on those who want to ban them.

Most planes currently in service were built way before everyone was running around with phones and laptops and iPods. Phones and spinning hard drives (the number two source of interference) were not an issue in airplane design, just like the future inventions of 2020 are not catered for in airplane design today.

Maybe the phones and laptops of 2030 won't ever be charged again because they contain a tiny little nuclear power source that keeps the device running until you die of old age. Should Airbus and Boeing already adjust the design of their planes because such a scenario might become reality? The technology in the planes flying around today dates from a time when nobody anticipated that cell phones would outnumber people.

The first iPod hit the market in 2001. Your average airplane is older than that. Back then most people did not use cell phones.

Managing risks is not an all-or-nothing game. On any given highway there are one or two drunk drivers, but they usually manage to complete their drunken trip without killing anyone. This is no reason to allow DUI, because then roadkill would turn from small chance to near-certain likelyhood.

The same reasoning applies to cell phones in planes: the risk of having one live phone aboard is small. Let's keep it small by not letting all 300 passengers yap away in mid-air.

There was an article a few years ago that found that about 1/3 of passengers carring cell phones inadvertedly left them on through the entire flight. This could be because the pushed the worng butto to turn them off, failed to make sure they were off, etc., etc. I carry at least two cell phones and I can assure you at times I have accidentaly not turned them both off.
Short of requiring everyone to turn in their cell phones at the Xray machines and giving them back to them on arrival at their destination (obviously impossible logistically), there will always be cell phones and other electronic devices in the 'on' position on an airplane during flight.

Wikipedia is not a good source, neither is the NASA study, as the ASRS system is nothing more than the personal beliefs of pilots reported to the system. There is no actual evidence that any of those reports is accurate. Some pilots use the ASRS system to cover mistakes. Say a pilot flies in the wrong direction by 6 degrees. He corrects his error, and to avoid potential FAA problems he files an ASRS report blaming a cell phone. This report then ends up in the NASA "study" of cell phone problems.


Within a few years we will all be allowed to use cell phones in the air. There is no possible way to test all of the possible variations of different electronic equipment, but they will allow cell phone use anyway. As has been stated here before, on any given flight there are probably 10-20 cell phones on and transmitting during the entire flight. Yet there has not been one verified report of a crash, not one verified report of a navigational error that ended up with the airplane at the wrong airport, not one verified report of an injury or death related to the use PED's.

The rules are just plain silly. Despite the requirements that cell phones and other devices be turned off I have personally witnessed the opposite on nearly every flight I've been on over the past year. IF there was any REAL risk associated with the use of these devices they wouldn't allow them on the plane. I can only assume that the airline's attitude is that the risks are sufficiently low enough that having x% of the passengers breaking them on each flight will not have any measurable deleterious effect.

There's no evidence that the NASA reports are accurate and there's no evidence that they are inaccurate. Some pilots may blame PEDs to cover up their own mistakes, and some pilots may not bother to report incidents because they don't want to deal with the paperwork.

Same goes for the number of PED-caused crashes. Crashes are so rare that statistical analysis becomes a matter of small numbers with a high level of uncertainty. There are plenty of security measures to reduce risks that didn't cause a crash yet. Given the consequences of a planeload of passengers going up in smoke the burden of proof should be with those who want to relax security measures instead of the other way 'round.

By the same line of reasoning you could claim that if there was any REAL risk associated with drinking and driving it wouldn't be allowed after the first beer instead of after the third.

There are plenty of things in planes with a real risk associated. Flammable liquids, carry on luggage, PEDs. It's the amount of risk that matters. A small percentage of radiating phones is less of a risk than having 100% of phones switched on.

That's why I'm suggesting they don't really care if a few passengers are violating the rules. The reality is they HAVE to know that some people are going to intentionally violate the policy...and even more will accidentally leave a device on for the duration of the flight. My assumption is that the measurable interference caused by this small number of devices is so low as to have no (measurable) effect on the electronics in the plane...but that they are simply erring on the side of caution by restricting them. If this was not the case the flight crew would no doubt be much more vigilant in their effort to prevent their use. I mean if you were a flight attendant and actually felt the plane was in danger wouldn't you?

If you think they're silly now, wait until we're required to sacrifice a goat to placate the angry gods before each flight.

Which only perpetuates the sheeple mentality.

If the amount of danger is below what I'm willing to accept I'll let it fly. Of course the amount of risk I'm willing to take depends on how easy it is to avoid it.

A simple announcement before takeoff is enough to cut the risk in half, a quick walk through the aisle to remind the hard of hearing that they really have to switch their gadgets off slashes it in half again, and telling passengers that the RF detector has picked up some live phones will let the number of offending Blackberries drop very close to zero. Yes, I've heard the RF detector message on more than one flight. If everyone keeps "forgetting" to switch their Nokias off RF detectors in the cabin may become as common as smoke detectors in the lavs.

Assumptions are tricky beasts.

There is a possibility of interference, but it's minimal. As to why the ped's aren't banned, in my experience the airlines feel that just telling people is enough. I've seen people go to the lav while the seatbelt sign is on and even while taxiing after landing. Rarely do the FA's even say anything about it.

On a Russian airliner I was flying on once a passenger went to the lav while taxiing and the pilot, for whatever reason, braked hard. I don't think there's any way that he knew the passenger was up, so I seriously doubt it was malicious. However, when the passenger complained about falling and cutting a nice little gash on his head, the FA and then the pilot basically told him he could find his own band-aid -- he should have known better than to be out of his seat with the seatbelt sign on. I and the rest of the passengers applauded.

Another incident with a laptop in a seatback pocket -- his seatmate gets up to go to the lav and the computer gets caught by his belt, flung across the aisle and breaks into pieces. Later at the gate I hear a supervisor tell him neither the airline nor the other passenger is responsible because the computer should not have been in the seatback pocket.

My opinion, you break the rules, the airline is relieved of all liability.

SR