Obviously planes don’t drop out of the sky the instant you turn on your mobile phone mid-air, as a poll by USA Today in 2011 showed about half of us defy airline rules on using electronics at all stages of flight. While many of us have wondered about the logic behind forcing electronics to be shut off during take-off and landing, banning the use of devices that emit and receive wireless signals intentionally seems more rational. At least on the surface, so does it really matter if you go into ‘airplane mode’ or not?

The Difference Between Electronic Signals

All electronic devices, when powered on, emit broadband electromagnetic interference (EMI and RFI), simply due to their use of electric circuits. That type of radiation is all around us and oozes out from your laptop power cable, digital camera, and even toaster ovens when they’re in use. Airplanes are shielded against EMI, since, at high levels it can interfere with navigational, communication, and other essential components. But gadgets give off miniscule amounts of broadband electronic interference and the counter-intuitively, the effect is not cumulative.

So 15 laptops on at the same time in flight isn’t 15 times worse when it comes to this undirected form of EMI. That radiation is a byproduct of electrical and magnetic circuits, however, wireless devices are a different matter. They’re designed to emit high-frequency signals to send and receive over large distances.

A mobile phone for instance, obviously intentionally, uses high frequency narrowband EMI, refereed to as radio frequency interference (RFI). Yet, despite the stronger emissions by iPad, laptop, et al wireless cards and cell phones, airplane shielding is more than adequate most of the time.

Risks At Various Stages Of Flight

According to The Survivor’s Club by Ben Sherman, 76.6% of people involved in plane crashes survive. The key difference between those who make it and don’t in survivable situations is action within 90 seconds of impact – 80% of which happen in the first 3 and last 8 minutes of flight. Amazingly, distractions like falling asleep, intoxication, and playing with mobile devices can shorten your attention span just enough, even in life-threatening situations. Not using electronic devices until you’re allowed reduces this risk.

Additionally for wireless use, there is a remote chance your device may interfere with emergency aircraft frequencies at a critical moment once you’re in the air. The real problem – and why these wireless and electronics bans are so broad – is because there are so many varieties of tech and gadgets.

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Banning Is A Blanket, Approving Is Individual

In the United States for example, the Federal Communications Commission (FCC) has banned the use of mobile phones in the 800Mhz range since 1991. They’ve toyed with the idea of lifting the ban as recently as 2004 but even if that were to happen, the Federal Aviation Administration (FAA) regulations would require hardware validation. That means every type of device (e.g. iPhone 3GS, iPhone 4, Samsung Galaxy S II, etc.) would have to be tested and approved – with every type of aircraft. You can see why they’re not to eager to lift an incredibly easy ban to implement. (In the European Union, moves have been made to merge agencies that handle aviation and mobile devices and why they’re much closer to allowing cell phones on planes.)

WiFi In Flight Is Extremely Unlikely To Harm Anything – Should You Disregard The Rules?

No. The first reason is that in most countries, the “rules” against active wireless devices inflight are “laws” which can carry stiff penalties if you’re caught and the airline decides to pursue the manner. (Unlikely unless you really piss off a flight attendant after they’ve said “cross-check”.) Secondly, talking on the phone isn’t going to win you points with your seatmates and unless there’s inflight wireless service, there won’t be much Internet browsing from your laptop or e-reader.

Finally, aside from, you know, being a good passenger and following the rules, keeping your wireless function turned off will give you much more battery life for the duration of your flight.