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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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FM radio receivers.
By drycrust3 on 12/27/2011 3:38:14 PM , Rating: 2
quote:
it was discovered that the FAA decided to allow American Airlines pilots to use iPads instead of paper flight manuals in the cockpit.


As I understand it, the origin of the rule related to passengers wanting to listen to their transistor radio while in the aeroplane. If you consider that an FM radio uses an Intermediate Frequency of 10.7 MHz, and that the aircraft band of 108 - 137 MHz is right above the commercial FM radio band of 88 - 107 MHz then you can see straight away the could be some sort of interference problem.
Since an FM radio uses a 10.7 MHz Intermediate Frequency, that means a passengers FM radio has its own local oscillator running at 10.7 MHz above whatever they are wanting to listen to, and since the aircraft band has less than 10.7 MHz separation from the commercial radio station band, that means when a passenger's transistor radio is tuned to less than 10 MHz from the top end of the dial, they are actually transmitting a weak but detectable signal right inside the civil aviation aircraft band!
So the question is does a typical "tablet" e.g. an iPad or Kindle, have an FM receiver built into it, and would that use a local oscillator that operates within the aircraft band?
According to the Jaxov website, the iPad uses a Broadcom BCM4329 chip, which isn't just for WiFi and Bluetooth, it also has FM radio TRANSMITTING and receiving capabilities!
http://jaxov.com/2010/04/ipad-can-play-fm-radio-br...
I haven't been able to find out what intermediate frequency the BCM4329 chip uses, but one could argue that in the absence of better advice, then it is better to believe the IF is 10.7 MHz, so iPads shouldn't be allowed to be used on planes, especially to listen to the radio during take off and landing.
According to the Blog Kindle website, the Kindle 4 uses the Atheros AR6103T-BM2D 26AR0620 chipset, which doesn't appear to have any FM radio transmitting or receiving capabilities.
http://blogkindle.com/2011/09/kindle-4-disassembly...
In addition, the Kindle Fire doesn't list any FM capabilities on its FCC certification:
http://wlanbook.com/amazon-kindle-fire-only-suppor...
So one could argue, that a Kindle Fire could be used safely on a plane!
Also, one could argue that because pilots are even closer to their civil aviation aircraft band receivers than passengers, then they should be using a Kindle and not an an iPad for their aircraft manuals.




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