Thinking Tech

The real reason you can't use the iPad on planes

The real reason you can't use the iPad on planes

Posting in Technology

There's still no evidence that our electronic gadgets will interfere with airplane function. So why the ban during take off and landing?

Millions of us will fly somewhere this holiday week. And we will be told to turn off all electronic gadgets. Or at least those gadgets with an “on/off switch,” as so many flight crew clarify for us.

Some of us comply. I fly so frequently that I often forget to do it. If it’s such a threat to airline safety why don't flight agents and crew require each passenger to prove that our various gadgets are indeed off? I mean they go to great lengths check our small items under the seat in front of us. And at security checks our lack of shoes and that terrifying 4 ounces of Vaseline hand cream?

In fact the U.S. Federal Communications Commission (FCC) has been against cell phone use, well, since cell phones existed. They officially banned them in 1991 for possible interference. But before that they were banned because they didn’t fit in the overhead luggage compartment.

From a blog post on the New York Times:

According to the F.A.A., 712 million passengers flew within the United States in 2010. Let’s assume that just 1 percent of those passengers — about two people per Boeing 737, a conservative number — left a cellphone, e-reader or laptop turned on during takeoff or landing. That would mean seven million people on 11 million flights endangered the lives of their fellow passengers.

Yet nothing happened. No planes stopped midair and plummeted due to signal interference. No planes enroute for Chicago wound up in Nova Scotia.

There is still no evidence that such electronics will interfere with the airplane’s systems. So why the rule? And why is it not enforced beyond a brief, yet somewhat strict, oral request from the crew?

Well, simply put, the U.S. Federal Aviation Administration (F.A.A.) always likes to err on the side of caution. In 2006 the FAA request the Radio Technical Commission for Aeronautics to test the effects of cellphones, Wi-fi and other devices on planes. They found no evidence to support the idea that such devices cannot interfere with the function of airplanes, and they found no evidence that they can affect flight safety. So there we have it. The problem.

But the idea that Kindles and iPads in “airplane mode” cannot be used during take off or landing doesn’t follow the logic of signal interference. There is no signal in airplane mode! In fact, pacemakers, hearing aids or even voice recorders are not on the FAA “turn off” list. Interesting.

From the New York Times:

Michael Altschul, senior vice president and legal counsel for CTIA, the wireless industry association, said a study that it conducted more than a decade ago found no interference from mobile devices.

“The fact is, the radio frequencies that are assigned for aviation use are separate from commercial use,” Mr. Altschul said. “Plus, the wiring and instruments for aircraft are shielded to protect them from interference from commercial wireless devices.”

Another curiosity: Why is it just for take off and landing?

Well apparently it’s less risky using electronics—the only exception is mobile phones—at levels above 3,000 meters. But not because of any technological reason, rather it gives more time for flight crew to deal with any possible problem with interference than they’d have during take off or landing.

Interestingly, the FAA allows for flight crews to use tablet computers, and has has allowed crews to use electronic flight bags since the 1990s to replace the huge paper aircraft manuals. And guess what? These planes all have Wi-fi.

It remains to be seen if the evidence will ever present itself. In the meantime here are a few solid facts we do know, as consolidated in Scientific American:

Radio-frequency emissions from cell phones, laptops and other electronics can occur at the same frequencies used by aircraft communication, navigation and surveillance radio receivers. These emissions could cause fluctuations in navigation readouts, problems with other flight displays, and interference with air traffic communications. [Note: This goes against what Michael Altschul notes above, proving the issue may be debatable?]

The FCC and FAA work in tandem to ban cell phones on airplanes. Even if a cell phone were to meet the FAA’s safety requirements, an airline would need an exemption from the FCC rule for that cell phone to be used inflight. Likewise, if the FCC rescinds its ban, the FAA would require an airline to show that the use of a specific model of phone won’t interfere with the navigation and communications systems of the specific type of aircraft on which it would be used.

RTCA, Inc., a Washington, D.C.-based federal advisory group, concluded that the FAA should keep its inflight restrictions in place after the group studied electromagnetic interference from cell phones and Wi-Fi transmitters in laptops from 2003 to 2006. At the same time, RTCA also published detailed processes that carriers and electronics makers can follow to certify such devices for inflight use if desired.

So on that last point, for those who would like to use cell phones on flights maybe we need to put more of the pressure on our carriers. Personally I relish the unplugging on flights. All I care about is to know what is a danger and what is not. I cannot be the only one forgetting to turn my gadgets off.

[via Scientific American and The New York Times]

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Christie Nicholson

Contributing Writer

Christie Nicholson produces and hosts Scientific American's podcasts 60-Second Mind and 60-Second Science and is an on-air contributor for Slate, Babelgum, Scientific American, Discovery Channel and Science Channel. She has spoken at MIT/Stanford VLAB, SXSW Interactive, the National Science Foundation, the National Research Council, the Space Studies Board and Brookhaven National Laboratory. She holds degrees from the Columbia University Graduate School of Journalism and Dalhousie University in Canada. She is based in New York. Follow her on Twitter. Disclosure