FAA device rules and the continuing problem of spectrum interference

This was bound to happen: the proliferation of mobile devices is beginning to cause the “incidents” involving airline passengers to rack up. From Nick Bilton:

In September, a passenger was arrested in El Paso after refusing to turn off his cellphone as the plane was landing. In October, a man in Chicago was arrested because he used his iPad during takeoff. In November, half a dozen police cars raced across the tarmac at La Guardia Airport in New York, surrounding a plane as if there were a terrorist on board. They arrested a 30-year-old man who had also refused to turn off his phone while on the runway… In 2010, a 68-year-old man punched a teenager because he didn’t turn off his phone. Lt. Kent Lipple of the Boise Police Department in Idaho, who arrested the puncher, said the man “felt he was protecting the entire plane and its occupants.” And let’s not forget Alec Baldwin, who was kicked off an American Airlines plane in 2011 for playing Words With Friends online while parked at the gate.

At issue is the largely unproven idea that tablets and phones interfere with a plane’s computers and communication devices. But, the asymmetry in rules for flight and takeoff is especially peculiar. When electromagnetic interference does happen with mobile devices, it is usually limited to a narrowband of the spectrum, due to inadequate filtering, tuning, or poor frequency control. The bands dedicated to aeronautical communication and telemetry are largely devoid of adjacent mobile ones, which does reduce the potential risk. Moreover, if there were interference problems of this sort, one would assume that they would happen during takeoff, landing and in-flight. Admittedly I am no aeronautical engineer, but I am not sure what kind of case for interference would make just takeoff and landing more risky.

Adjacent band interference was at the center of another debate in early 2012: LightSquared’s troubles with GPS devices. Ultimately, the company could not deploy their 4G network because of the interference problems it created for GPS devices, but these were known problems that LightSquared tried to innovate around. As the piece explains, the FAA announced in October that it would review its policies on the use of electronic devices during all stages of flight due partially to Chairman Genachowski’s instance. Being chastised by the FCC that you need to review your rules is bad, especially considering that it still had a number of outdated telegraph laws on the books until the late 1990s. Perhaps others might be able to comment, but I am at a loss to describe the harm imposed by the rules. Sure these rules are inconvenient, but they are actually better at showing the regulatory inertia whenever any rule is adopted, which should make us all a little more wary.

First published Jan 3, 2013