Using ebook readers on aeroplanes?

[drofgnal]

This type of thread pops up every now and then. I've responded to this same issue months before. I'm an aerospace engineer, although this is not my specific area, I know a little about this.

The potential problem is real. To know this all you have to do is put a blackberry or smartphone beside a speaker phone and listen to noise coming over the air. Now if 200 people pull out wi-fi or even worse 3G devices in a confined space the EM noise could be significant. The problem is radiated emissions of the device (and susceptibility of the circuit) causing noise in an adjacent circuit. (manufacturers also test for conducted emissions and susceptibility.) An awful lot of testing goes into certification for electromagnetic enviromental effects.

Turning all electronic devices off during the first few and last few minutes even those without transmission capability seems stringent, (and on this point I'm not real sure) but remember it is during these times that planes are following routes to/from the landing strip based on signals (electromagnetic) from ground beacons as well as talking to the tower (radio) and being under the influence of the airport radar. Some caution is called for given the dense traffic that can be in the vicinity of the airport and the dire consequence of a mishap. Also note that you don't have to have a transmitting device for a device to have radiated emissions. Any time varying electric current produces a subsequent magnetic field in the vicinity of the circuit and as such is a source of radiated emissions.

As far as some planes allowing wi-fi in the future, that will imply a rigid certification of the planes devices in operation with multiple devices that passengers could carry. The planes side will be wired into the planes avionics and will undergo a rigid certification to assure it does not interfere in operation with navigation or communication systems of the aircraft. I suspect not many will do this as this will be a huge expense for many.

As far as myself, I can read with my ipad in airplane mode or my kindle with 3g off for the few hours of a domestic flight. For longer flights (international) a movie and a nap are usually in order!

[mldavis2]

Good to hear from someone who knows a bit about it. I'm a chemist and flight simulator fanatic, so I have only basic awareness of RF use on aircraft. To my novice mind, there are a couple of potentially problematic areas.

First, aircraft utilize IFR equipment to lock on to directional beams that enable them to land in near zero visibility (Cat IIIa). These are RF signals received by the aircraft from transmitters near the runway approach that lock the aircraft autopilot on to both horizontal and vertical approach paths (IFR) in bad weather. These are highly directional so a false signal from behind the cockpit would not be expected to cause a problem. However the combined RF from 150 devices 'could' cause sufficient noise as to render the equipment unstable, I suspect. Most landings are done under visible conditions but the IFR glideslopes are utilized just the same.

Another problem is the radar. There are two types -- air traffic, and weather. Weather radar is not as big a potential problem because it is forward seeking and primarily used enroute to locate storms, when electronic devices are allowed. The other is air traffic which is used to detect potential collisions with nearby aircraft. This radar is much more omni-directional because it must look up, down as well as front, back. This can be critical when taxiing around an airport or for double checking incoming traffic that may potentially cross a take-off or landing path. Again, air traffic controllers are supposed to handle this, but you don't cross an intersection just because the light is green without looking for cross traffic that may be out of sync.

It's just an extra layer of safety involving hundreds of lives. If you think you're an exception to the request and the law, go for it. You won't be sitting next to me without a request to turn your toys off for just a few minutes.

[Jellby]

Regardless of whether it's safe or not, think of it as the pilot saying: "OK, now I have to concentrate really hard, so everyone please sit down and keep quiet, and stop drumming your fingers on the armrest!"

You can say "but I'm drumming really low, you can't possibly hear that", but you are just being a [put your favourite word here]. Even if you manage to talk with your neighbour and hum that silly song without being noticed, you are only showing your lack of respect for social norms and polite behaviour.

[sunnysmiles]

Originally Posted by JSWolf

wifi is not an issue on planes. In fact, some planes do off wifi on board now.

I know Egypt air does on its new planes They even announced you can use your phone too.

[jbjb]

Originally Posted by drofgnal

This type of thread pops up every now and then. I've responded to this same issue months before. I'm an aerospace engineer, although this is not my specific area, I know a little about this.

Thanks for your educated input!

I'm an electronic engineer, so I have a pretty good understanding of radiated emissions and immunity but I have no particular experience in aircraft.

As far as some planes allowing wi-fi in the future, that will imply a rigid certification of the planes devices in operation with multiple devices that passengers could carry. The planes side will be wired into the planes avionics and will undergo a rigid certification to assure it does not interfere in operation with navigation or communication systems of the aircraft. I suspect not many will do this as this will be a huge expense for many.

Agreed. It's helped somewhat by the fact that the presence of things like a cellphone picocell on the aircraft will reduce the radiated power from devices. In the absence of these they would ramp up the power as they tried to make contact with something.

/JB

[LakeLoon]

Proponents of keeping the current rules in place have some legitimate points, but they are often justified poorly. That's frustrating to many of us.

I suspect that most knowledgeable engineers/operators can come up with theoretical risks and failure modes for virtually any complex system. What we really want to know, what is interesting in practice, is the LIKELIHOOD of such failures. It may be that even the best experts cannot quantify the likelihood, but I for one would appreciate a better explanation of which variables can be quantified and which can't, and why. From the experts, not from rubberneckers like myself.

The mantra that "any avoidable risk is too much" is not consistent with our everyday experience. People are often willing to exchange small risks for tangible benefits in many aspects of our lives, from what we choose to eat to the speed limits we impose on highways. Now, people are often very bad at estimating risks, especially small ones, and experts are probably better suited to quantify risks and benefits. But it seems unsatisfying to leave it at "the risk is nonzero and avoidable, so we will place the entire burden of proving lack of risk on proponents of change." That sounds a lot like "it's hard and we're subject to criticism if we get it wrong, so we'll punt."

To a lay observer, the evidence--based on firsthand experience and formal studies--of widespread use of PEDs during all phases of flight, with few reports of serious consequences, seems substantial enough to merit analysis. It might help us estimate at least an upper statistical limit on the risks. If that's not true, we'd like to know why, and whether there is at least some subcategory of conduct (e.g. using Kindles with wireless off) that appears safe. I'd also like to see the experiences from noncommercial flight, where the restrictions on PEDs are less stringent, taken into account.

Regulators can't measure every little thing, and some assessments may be too complex or expensive to undertake. But I believe the cumulative impact of the current rules is frequently underestimated. The period of "no electronics use" on flights can be quite long--an hour or more--and the restrictions often meaningful. Consider, for example, the professional who could be reading emails or writing documents. Consider also that many people place a high value on engaging in their distraction of choice, even if you're not one of them. And even if the negative impact in an individual case is small, when multiplied over all the passengers on all of the flights, it might be much larger than you expect.

My provisional "rubbernecker" conclusion, undoubtedly based on imperfect evidence and analysis, is that using an ereader with wireless off during taxi, ascent, and descent poses negligible risk of interfering with the plane's critical systems. If the risk is negligible, I think I should be allowed to do it. Regulators who say "no" should show their work; after all, my taxes pay their salaries.

[mldavis2]

LakeLoon's point is well taken, however, as I stated in an earlier post, with the plethora of new RF-emitting devices coming out every day or two, it is impossible if not economically unsound to attempt to create a list of every 'approved' device tested and found safe. Each individual device would have to be tested on each of dozens of commercial aircraft from dozens of different cabin locations at each of hundreds of IFR frequencies used by the various airports. Multiply all the safe devices together, all running simultaneously on one aircraft with 120 passengers, and you have the potential for a nasty stew. The brain-dead simple solution is to simply have them turned off during critical stages of the flight.

However the point is moot, since it is an FAA regulation in the U.S.; and to challenge the rule by ignoring it is to risk a conference with the air marshals who know nothing about RF interference potential, and everything about the FAA rules.

[LakeLoon]

Originally Posted by mldavis2

LakeLoon's point is well taken, however, as I stated in an earlier post, with the plethora of new RF-emitting devices coming out every day or two, it is impossible if not economically unsound to attempt to create a list of every 'approved' device tested and found safe. Each individual device would have to be tested on each of dozens of commercial aircraft from dozens of different cabin locations at each of hundreds of IFR frequencies used by the various airports.

Thanks, and I don't mean to downplay the practical difficulties. I'm just not convinced they are insurmountable, nor that there are no creative solutions that meet people halfway. For example, a rule that says "devices no larger than X, with an 'airplane mode' that shuts off all radios, and whose shielding meets FCC guidelines X,Y, and Z, can get certified with a relatively simple approval process. Devices bearing the logo for this certification can be used during taxi, ascent, and descent." would be a lot better than the current regime. Is it really impractical to develop functional guidelines that would not require exhaustive testing for each separate unit? I mean, we already have "category based" rules for cruising flight; it's not obvious why it would be impossible for the more "sensitive" portions of the flight.

Manufacturers would have the burden of getting the certifications, and would obviously be liable for false representations/branding . . . but this would be feasible, as opposed to saying "each manufacturer must shoulder the entire bill for testing their specific device under all variables."

This solution might not be ideal either. My point is, it's not necessarily all or nothing.

[Lady Fitzgerald]

Why is it people have problems just following the rules. If they have problems with the rules (and I'll admit a lot are just flat stupid), there are channels for dealing with it. Just ignoring them is not the answer.

[drofgnal]

Originally Posted by LakeLoon

Proponents of keeping the current rules in place have some legitimate points, but they are often justified poorly. That's frustrating to many of us.

I suspect that most knowledgeable engineers/operators can come up with theoretical risks and failure modes for virtually any complex system. What we really want to know, what is interesting in practice, is the LIKELIHOOD of such failures. It may be that even the best experts cannot quantify the likelihood, but I for one would appreciate a better explanation of which variables can be quantified and which can't, and why. From the experts, not from rubberneckers like myself.

The mantra that "any avoidable risk is too much" is not consistent with our everyday experience. People are often willing to exchange small risks for tangible benefits in many aspects of our lives, from what we choose to eat to the speed limits we impose on highways. Now, people are often very bad at estimating risks, especially small ones, and experts are probably better suited to quantify risks and benefits. But it seems unsatisfying to leave it at "the risk is nonzero and avoidable, so we will place the entire burden of proving lack of risk on proponents of change." That sounds a lot like "it's hard and we're subject to criticism if we get it wrong, so we'll punt."

To a lay observer, the evidence--based on firsthand experience and formal studies--of widespread use of PEDs during all phases of flight, with few reports of serious consequences, seems substantial enough to merit analysis. It might help us estimate at least an upper statistical limit on the risks. If that's not true, we'd like to know why, and whether there is at least some subcategory of conduct (e.g. using Kindles with wireless off) that appears safe. I'd also like to see the experiences from noncommercial flight, where the restrictions on PEDs are less stringent, taken into account.

Regulators can't measure every little thing, and some assessments may be too complex or expensive to undertake. But I believe the cumulative impact of the current rules is frequently underestimated. The period of "no electronics use" on flights can be quite long--an hour or more--and the restrictions often meaningful. Consider, for example, the professional who could be reading emails or writing documents. Consider also that many people place a high value on engaging in their distraction of choice, even if you're not one of them. And even if the negative impact in an individual case is small, when multiplied over all the passengers on all of the flights, it might be much larger than you expect.

My provisional "rubbernecker" conclusion, undoubtedly based on imperfect evidence and analysis, is that using an ereader with wireless off during taxi, ascent, and descent poses negligible risk of interfering with the plane's critical systems. If the risk is negligible, I think I should be allowed to do it. Regulators who say "no" should show their work; after all, my taxes pay their salaries.

You deal with likelihood and not properly the consequence. The ultimate consequence could be disruption of navigation and comm to the point of midair collision, missing the runway, or worse. Although a few bad accidents have had many survivors, most end in everyone dead.

[drofgnal]

Originally Posted by sunnysmiles

I know Egypt air does on its new planes They even announced you can use your phone too.

Yes, they have certified it for that. The question is would their certification pass FAA standards, I don't know. Many nations use FAA standards, but who knows which do and which don't. Cell phone use is possible as mentioned jbjb but you need the picocell mentioned to prevent the cell phone from boosting power to its highest levels in search of a signal. This is compounded by the fact that in an aluminum tube the outside signal its is very reduced so the cell phone will probably naturally boost power to the maximum.

[SidneyW]

I flew with my Kindle recently and didn't even think about switching off the wireless when I was switching my phone to airplane mode. I guess it was not really active since it was not on, but when I turned it on and realized the wireless was live I de-activated it.

I never heard anything from the cabin crew.

[LakeLoon]

Originally Posted by drofgnal

You deal with likelihood and not properly the consequence. The ultimate consequence could be disruption of navigation and comm to the point of midair collision, missing the runway, or worse. Although a few bad accidents have had many survivors, most end in everyone dead.

Your comment is valid, and it is something I considered . . . it's hard to cover all the bases when trying to keep comment length down! A proper cost/benefit analysis must, of course, consider both the likelihood of harm and the probable consequences. Such concepts are often contemplated in the law, such as in the "Hand formula" concept that underlies much of tort law.

A plane crash is bad. Conduct that might crash a plane one time in ten thousand would be far too dangerous. But if the conduct was estimated to cause a plane crash once every thousand years based on current daily flight traffic, I wouldn't worry too much about it. Others might be more concerned, and that's okay. It's worth discussing.

[ClairePMR]

Then there's this comment from a pilot in an article published first in Reader's Digest and excerpted on HuffingtonPost:

“We don’t make you stow your laptop because we’re worried about electronic interference. It’s about having a projectile on your lap. I don’t know about you, but I don’t want to get hit in the head by a MacBook going 200 miles per hour.” -Patrick Smith

http://www.huffingtonpost.com/2010/1...7.html#s161027

[LakeLoon]

Originally Posted by Lady Fitzgerald

Why is it people have problems just following the rules. If they have problems with the rules (and I'll admit a lot are just flat stupid), there are channels for dealing with it. Just ignoring them is not the answer.

I agree! I always cringe when I see folks on the plane challenging the flight attendants, even when it's just something small and passive-aggressive like failing to put the seat back up all the way.

But, of course, believing that passengers should obey the flight crew is not the same as agreeing that the rules they impose are good ones. Which is why discussions like this are valuable.