Take off your shoes and belt? Sure. Walk through a metal detector with your arms raised? Why not? Stop using your mobile device? Not on your life! Despite all the precautions taken to make flight travel safe, travelers seem to disregard the rules when it comes to using electronic devices on planes. For some reason, people tend to think that all the warnings given by the flight crew are just made up and have no basis in fact. So why do we have to turn off electronic devices on airplanes?

What Do Electronics Interfere With?

Interior view of cockpit with pilot and copilot managing electronic controls
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Electronic devices operate as both transmitters and receivers of radio waves. Typically, these are low power waves that don’t interfere with anything. But as the distance from the transmission source, like a cell tower, gets farther away, the device needs to send out stronger signals to reach it. In a plane, you’re about as far away from a cell tower as you can be. If your phone isn’t in airplane mode, those increased waves have the potential to interfere with airline communication and navigational equipment.

Early Electronic Devices

Up close view of hand turning the dial on an old-fashioned FM radio transmitter
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Since the 1960s, electronic devices have been blamed for numerous flight errors such as course miscalculations and autopilot malfunctions. In 1963, the Radio Technical Commission for Aeronautics (RTCA) declared that portable FM radios were responsible for flight system errors. They claimed that by limiting the number of electronic devices that emit high intensity radiated fields (HIRF), airlines would experience fewer errors and safer flights. Following the announcement, passengers heard the world-famous “turn off your electronic devices” speech for the first time.

Airlines began to install shielding on their sensitive equipment that would protect communication and navigation systems from interference, but electronic devices continued evolving about as quickly as the airlines could shield against them. By the late 90s and early 2000s, cell phones had become mainstream, causing another heap of problems for airlines.

In 2003, an airline came down to an altitude of 2,500 feet on approach to an airport. As it came out of the clouds, the pilot realized that even though the plane had been on autopilot, it was a full mile off course! The mix-up was blamed on an electronic device interfering with the plane’s navigational system. The instruments are so sensitive that even the smallest interference can result in being miles off course.

Proof of Interference

Woman on plane taking photo out the window
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Despite the several instances of pilots and flight crews blaming electronic devices for system errors, the results have never been replicated in controlled experiments. In 2007, the Federal Communications Commission (FCC) actually considered lifting the electronics ban on airplanes because of the lack of evidence but ultimately decided to leave the restrictions in place to play it safe.

Although there is the potential for interference, it’s very low, and even then, is unlikely to cause any real harm. Flight crew members aren’t even required to turn off their phones according to general operations manuals. They have to be reminded to do so the same as everyone else. Most airlines have the freedom to enforce as many or as few rules regarding electronic devices as they see fit. Some airlines don’t care. Others, like certain Chinese airlines, will enforce fines and even jail time for using electronic devices on a plane.

Crew Communication Interference

Pilot wearing headset communicating with control tower
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The most likely reason that electronics are banned on flights is that they can be annoying for flight crews. The headsets and phones that they use to communicate also work on similar frequencies as the ones emitted and received by electronic devices. Sometimes this interference can come across as a persistent hum or scratching noise. If you’ve ever left your cell phone too close to your radio alarm clock on the nightstand, you might have heard the interference. Imagine constant buzzing and humming in your ears as you try to pilot an 85-ton plane for a six-hour flight. It’s not enjoyable.

So, do electronic devices actually interfere with airline systems? Maybe. There has been very little evidence to support the argument. The bottom line: Listen to the flight crew. If they decide that you shouldn’t use electronic devices, just go with it. Is it really worth system interference or even crew member annoyance just to finish your game of internet Scrabble?