We all know the announcement before take-off and landing asking us to either close our electronic devices or put them in airplane mode. Regardless of whether the request is actually followed by all the passengers on the plane, why do electronic devices have to be closed or in airplane mode when flying?
From an accident investigation perspective, we have no evidence whatsoever that this has caused an accident, but that doesn’t mean that it can’t be responsible for an accident or that it can’t cause an accident.
Shawn Pruchnicki, professor at The Ohio State University
Although it has not happened yet, a cell phone could in theory cause a plane to crash if not put in airplane mode. The aircraft’s navigation and communication instruments are very sensitive and extremely precise, the slightest variation can have tremendous effects, “especially when we’re doing an instrument landing”, former pilot and aviation safety expert Shawn Pruchnicki explained for USA Today.
“Those signals are very, very precise, and the autopilot flying those signals is also very, very precise. This is not the time when you want any variability at all, especially when you have terrain considerations. This is even more of an unknown because the newer aircraft that we have out there are even more sophisticated and are even more automation-dependent”, Pruchnicki said.
The US Department of Transportation’s Federal Aviation Administration (FAA) regulations prohibit the use of certain portable electronic devices on aircraft unless the operator determined they cannot interfere with navigation or communication systems. If a device gets clearance from the operator that it will not interfere with the onboard instruments, it could, in theory, be used while flying, however, testing all the existing cell phone models on all the existing aircraft to see if there is any interference is not feasible.
In the particular case for 5G, there are bands that are far enough in frequency from the frequencies the airplane uses that the risk is minimal.
Eduardo Rojas-Nastrucci, associate professor at Embry-Riddle Aeronautical University
With the deployment of 5G however, the rules could change in the near future. The European Union has already announced the use of mobile devices will soon be allowed on planes since the frequencies 5G works on differ enough from the ones of the plane instruments as to not cause any trouble.
“In principle, any wireless device may interfere with systems in the airplane such as the radio altimeter. But in the particular case for 5G, there are bands that are far enough in frequency from the frequencies the airplane uses that the risk is minimal”, said Eduardo Rojas-Nastrucci, an associate professor of electrical and computer engineering at Embry-Riddle Aeronautical University.
Even so, Pruchnicki still recommends passengers to use the airplane mode on their phones. Besides the risk to the flight, he pointed out that cell phones trying to connect to a network during take-off and landing can overload them because they link to multiple towers at once. “With so many unknowns and lack of testing, why would you put the flight at risk just to advise your family that you’re five minutes from landing?”, he remarked.
