Anyone who ever flew on a commercial airplane was asked to turn off his phone by the flight crew. This practice has a long history and was already present when modern smartphones weren’t invented. A common reason is that the phone’s communication systems might interfere with the plane’s radio equipment.
Hundreds of passengers every day still forget to turn off their phones (I know I have), but there are no headlines in aviation news that the same number of planes are falling down. So, why exactly do we need to turn off our phones during a commercial flight?
The use of equipment that can transmit radio signals (including Bluetooth, telephony, and Wifi) is prohibited in all planes by government recommendation.
The Federal Aviation Administration (FAA) made a recommendation for passengers not to use cellular data on planes. Airlines, in turn, have made it their internal rule to prohibit all use of such devices.
Airlines might face a fine if their plane crashes or create some other risk for passengers because of not enforcing such rules. The regulation is a worldwide one. China, India, Australia, and most other airspaces are also following the same prohibition principle.
But there are signs that these rules are getting relaxed. In 2022, the European Union announced plans to enable 5G usage in airplanes, arguing that the newest generation of communications technology is no longer a threat to modern airplanes.
This shift in regulation begs the question – has it ever been so dangerous to use a phone on a plane?
Most planes, most of the time, are not controlled by pilots. It might sound improbable, futuristic even, for a passenger who is not well-versed in how modern airplanes function. But machines do, in fact, accomplish most of the flight, including the take-off, landing, and cruising.
The automatic flight control system on a plane is actually a lot of systems working together. They function by sending radio frequency signals to one another with various data about fuel reserves, altitude, speed, and so on. More importantly, these systems communicate with flight control centers on the ground.
The flight path for each plane is created according to weather conditions and the location of other planes. All of this information is reported to the automatic flight control system by the flight control center. The pilot might also need to contact the airports or other aircraft, but It’s usually only in emergencies or other extraordinary situations.
All of these devices use the same radio frequencies as your mobile phone. The problem is that there are no ways to prioritize certain signals over others. Every radio signal is of equal value to the receiver on the plane. No matter if it is your call to a friend or a pilot trying to contact the flight control center for an emergency landing.
Similarly, when you hear your radio station chippering and breaking due to a close-frequency radio station, your phone might, in theory, interfere with the plane’s automatic flight systems.
So, a situation is possible where, due to the number of users on certain frequencies, the plane will no longer be able to communicate with the flight control center, other pilots, or, in extreme cases, automatic flight systems.
A matter of probability
European Union is able to allow some 5G communications on planes as they have recently switched their radio frequency usage guidelines and reserved frequencies specifically for planes. It means that no phone carrier uses plane frequencies. Thus, there is no interference and possible slowdown of communications if you use your phone with 5G.
Of course, some other devices might still use older frequency ranges (3G, for example), which might take the valuable space in radio frequencies needed for planes. Therefore, the airplane mode as we know it is likely to change, but it will not go away completely.
In fact, the reasons for getting rid of the airplane mode have been here for a couple of decades already. The FAA ordered a scientific investigation into the effects of using phones back in 1992. The study has not found any measurable effects, even when subjected to a really high demand for radio frequencies.
However, more testing on the matter is needed as the theoretical implications of a possible radio frequency disturbance are there. The disturbances are a matter of probability and the more phone usage on planes is common, the more it is likely that a critical disturbance will happen.
That’s the reasoning behind the decision to prohibit the use of phone signals on planes. But what would happen if you did not turn off your phone during a flight?
What raises the risk
Every phone without an ariplane mode enabled is set to automatically connect to the nearest cell tower. Such an automatic signal is quite insignificant and unlikely to disrupt the radio signals of a plane.
Additionally, most long-distance flights happen above 10,000 feet in the air. Highly unlikely that your phone will get any reception at such a height at all.
However, if you were to receive a text message, call, or connect to the internet during take-off or landing, phone usage becomes a bigger problem. A phone that tries to connect to a ground tower for a call will inevitably use the frequencies more intensely.
Another factor is your distance to the pilot’s cabin. Larger aircraft will naturally have more barriers between the pilot’s cabin and the passengers. The closer you are to the front of the plane, the more disruptive your phone will be to the pilots. Most popular commercial planes have their radio transmitters at the front.
The effect of turning on a phone on a plane is that of an annoyance to the pilots more than a real risk in most cases. But the possibility of real danger to the expensive equipment and human lives is still there. Better not risk it and turn on that airplane mode.