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  (Source: kindleboards.com)
According to researchers at EMT Labs, tablets and e-readers such as the Amazon Kindle do not pose much of a threat at all

The Federal Aviation Administration (FAA) has banned airplane passengers' use of mobile electronics like iPads and Kindles during takeoff and landing due to interference, but recent results from EMT Labs challenge this ban and further raise the question, "Why not?"

Earlier this month, it was discovered that the FAA decided to allow American Airlines pilots to use iPads instead of paper flight manuals in the cockpit. This raised a few eyebrows, since passengers are banned from using such electronic devices during takeoff and landing due to possible interference with sensitive airplane electronics.

Many wondered how the iPads would affect these important electronics when used so closely to such equipment, but the FAA justified the decision after conducting a test of the use of mobile electronics in the cockpit. It also said that having one iPad per pilot versus an iPad or Kindle for every passenger made a big difference in the level of interference.

However, The New York Times now disagrees with the FAA's reasoning after taking a trip to EMT Labs, which is an independent testing facility in California that screens the electrical emissions from different gadgets.

According to researchers at EMT Labs, tablets and e-readers such as the Amazon Kindle do not pose much of a threat at all. The FAA has specified that a plane is only approved as safe if it can withstand up to 100 volts per meter of electrical interference; EMT Labs says an Amazon e-reader emits under 30 microvolts per meter when in use, which is 0.00003 of a volt.

"The power coming off a Kindle is completely miniscule and can't do anything to interfere with a plane," said Jay Gandhi, chief executive of EMT Labs. "It's so low that it just isn't sending out any real interference."

In addition, the FAA is apparently wrong when it comes to the "two tablets versus many" theory. EMT Labs argued that electromagnetic energy doesn't add up as more e-readers are used on the plane; rather, the "noise" from such gadgets decreases as more are used.

The FAA does allow gadgets such as voice recorders to be used during takeoff and landing, but as it turns out, a Sony voice recorder emits more electrical interference than a Kindle.

According to Bill Ruck, CSI Telecommunications' lead engineer, the FAA only bans tablets and e-readers during takeoff and landing because of "agency inertia and paranoia."

While the EMT Labs tests didn't provide specific results concerning iPads instead of e-readers, which are the devices in question regarding use in the cockpit during takeoff and landing, this is a solid first step in finding out why the FAA is really banning these gadgets.

Source: The New York Times



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How can you trust a company that states...
By HoosierEngineer5 on 12/27/2011 12:37:00 PM , Rating: 3
"electromagnetic energy doesn't add up as more e-readers are used on the plane; rather, the "noise" from such gadgets decreases as more are used."

This is totally inaccurate. Electromagnetic energy adds up as the vector sum of all the emitters. Also, who's to say (without testing and certification) that a particular device does not emit detectable amounts of energy. Remember, the clock frequency of many of these devices is much higher than the operating frequencies of many radio receivers. Depending on what the device is doing, measurable RF energy can be emitted from the very high speed switching signals. Even lower frequency signals can radiate at harmonic frequencies, especially if the signal edges have high slew rates, and if the signal is not properly terminated in the line's characteristic impedance.

The easiest way to build an amplifier is to design an oscillator. The easiest way to build an oscillator is design an amplifier. How do you know every device anybody carries on a plan will not radiate at the frequency of the aircraft communications gear?




RE: How can you trust a company that states...
By Gondor on 12/27/2011 3:46:45 PM , Rating: 3
quote:
This is totally inaccurate. Electromagnetic energy adds up as the vector sum of all the emitters.


This is not "totally inaccurate". Given sufficient number of emitters you will inevitably get some out-of-phase signals that cancel each other out so there is no way N phones, each generating M amount of RF noise, would generate N * M noise combined.

quote:
Remember, the clock frequency of many of these devices is much higher than the operating frequencies of many radio receivers. ...


Which affects airplane electronics ... how ? If it was the other way around (airplane navigation etc. working on higher frequencies where harmonics of lower frequency signal could disrupt their operation) your argument would make sense, but it's not. Plus the amount of energy radiated as harmonics of base frequency is significantly smaller.

As people have pointed out above your post: if RF interference from consumer electronics could bring an airplane down we would be having shitload of crashes every day because PEOPLE ARE LAZY and simply leave their hadhets on (or in normal operation mode even though the devicemight have "flight mode" switch capability) even when told not to. And yeah, terrorists would be all over this as well, not even sending their people aborad but simply mailing active cellphones from one place to another ...

No need to spread FUD.


RE: How can you trust a company that states...
By tamalero on 12/28/2011 12:18:55 AM , Rating: 2
The problem still seems to rely on "chance" or probability, rather than plain black and white answers.

even if its not "totally inaccurate"
what is the change they signals will cancel each other?
probably the same probability and chance than getting increased?
in short, both can happen randomly?
anyway pretty sure it doesn't matter how much times you get the cancellation or not.. if you get the spikes that might affect avionics.. you STILL GET YOUR ELECTRONICS AFFECTED.

And you seem to exaggerate the whole thing..
some people might talk about taking down planes, but pretty sure they mention incorrect data that might affect how the pilots receive and process said data.
the crash of air France, where the on-board computer was giving incorrect and conflicting data would be a fine example.
The pilots didn't know what the hell was going on, and the sum of the incorrect data, with the bad choices of the pilots made the whole plane crash.

Remember most accidents are always the sum of a lot of small errors, mistakes and problems.. that keep piling on each other.. going above each protection and security procedure.
While you're going to the extreme to say "its silly" because no signal can take down a plane.. it might start the line of events that concludes in a crash (again, similar to that airfrance flight)


By Warwulf on 12/29/2011 5:38:41 AM , Rating: 2
Except that the faulty data was a result of poorly designed pitot tubes and not from consumer electronics.

Nice try reaching for a parallel example. "A" for effort.


By Warwulf on 12/29/2011 5:42:46 AM , Rating: 2
A better example would have been the uncommanded nose down pitch changes as a result of random variation in the inertial sensor which happened coincidentally at 1.2 seconds apart. This was onboard a Qantas A380, by the way.

And consumer electronics were not blamed. Software changes were undertaken on all A380 flight computers to prevent recurrence.


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