updated 08:50 pm EST, Sun December 25, 2011
Tests suggest no effect from devices in airplanes
An examination of the FAA's rules demanding shutdowns of electronic devices during takeoff and landing has cast more doubt on the ban. The New York Times found through EMT Labs tests that the electromagnetic interference from current devices, such as an Amazon Kindle and a Sony voice recorder, was around 30 microvolts, or well under the 100 volts per meter limit the FAA demands. While iPads weren't measured, they too would be well under the limit.
FAA arguments that many more devices would cause dramatically more interference also didn't hold up. CSI Telecommunications head engineer Bill Ruck noted that interference doesn't scale directly and slows down as the number of devices goes up. If a full cabin interfered with an airplane, no one could safely enter an office building "without wearing protective gear," EMT labs testing lead Kevin Bothmann said.
A Boeing engineer that co-authored a 2006 FAA report that enforced the device bans during takeoff and landing acknowledged that at least some devices, such as the voice recorder, didn't cause interference. No explanation has been given directly responding to the challenges, however.
The new study isn't definitive proof of a lack of issues. It may still point to the FAA rules being based more on stereotypes and early reactions than actual knowledge.