The Consequences of Not Activating ‘Airplane Mode’ During a Flight

In a recent shocking episode of Succession, the most surprising moment wasn’t the major plot twist—it was the realization that nearly all passengers on the private jet were making calls throughout the flight.

While the Roy family's inner circle is notorious for bending the rules (and their private jet likely has its own set of guidelines), shouldn’t they have switched to airplane mode for everyone’s safety? Can you even make phone calls over the Atlantic? We’ve all been conditioned to believe that keeping cellular service active during a flight is riskier than indulging in a third Bloody Mary on an empty stomach. So, what exactly does airplane mode do? Here’s what travelers should understand about airplane mode and the implications of neglecting to activate it before takeoff.

What is airplane mode?

Activating airplane mode turns off all wireless and cellular signals on your device. However, once your phone is in airplane mode (also known as flight mode on some devices), users can manually reactivate certain signals like Bluetooth and Wi-Fi. Whether you should do so is another matter altogether.

Why must passengers set their phones to airplane mode?

According to the FAA's Safety Information page, "The FCC and FAA prohibit the use of cell phones while airborne due to the potential for signals to disrupt vital aircraft instruments. Devices should be in airplane mode or have their cellular capabilities turned off. If the plane is equipped with Wi-Fi and the airline permits it, you may utilize the Wi-Fi connection on your device."

What are the consequences of not switching to airplane mode during a flight?

The primary concern is that a phone's radio signals might interfere with the systems used by the aircraft during flight. The FAA website states, "There have been instances reported of suspected interference with communication and navigation systems documented in both NASA's Aviation Safety Reporting System and the FAA's Service Difficulty Reporting system."

Additionally, if the captain determines that safety is at risk—such as during a landing with limited visibility—they have the authority to instruct passengers to completely turn off their phones to ensure no interference with onboard communication and navigation systems.

Is it even possible to make calls at 36,000 feet?

In theory, yes. Sven Bilén, a professor at Penn State University specializing in engineering design and aerospace, explains in How Stuff Works that if the aircraft is flying low enough (typically below 10,000 feet), cellular calls might connect. However, since the plane would be switching between different cell towers as it travels, the call quality would likely be poor and could disrupt ground networks. Above that altitude, making a cellular call is unlikely unless the plane has its own mobile service (as Virgin Atlantic did in the 2010s, and likely the Roy family jet as well). However, this doesn’t mean that cell phone calls are permitted. In the U.S., the Code of Federal Regulations stipulates that the FCC forbids cell phone use when the aircraft is in flight. It states:

"Cellular telephones installed in or brought aboard airplanes, balloons, or any other type of aircraft must not be operated while such aircraft are airborne (not in contact with the ground). When an aircraft takes off, all cellular telephones on board must be switched off."

Are the regulations different in the U.S. compared to other countries?

Yes, the differences arise from the communication technologies employed in various countries and their respective airline safety regulations.

For instance, at the close of 2022, the European Commission determined that airlines could utilize 5G during flights and mandated that EU member countries must have 5G technology accessible for aircraft by June 30, 2023. However, this doesn’t necessarily signal similar changes in the United States: Boeing, Airbus America, and the Airlines for America trade group have contended that 5G might compromise safety by disrupting a plane’s radio altimeter, which measures the aircraft’s altitude—a crucial function, especially in adverse weather conditions.

Conversely, the 5G used in the U.K. and EU operates differently. "There is significantly less chance of interference," stated Dai Whittingham, chief executive of the U.K. Flight Safety Committee, in an interview with the BBC. "We use a different frequency spectrum for 5G, and the power levels permitted are lower than those allowed in the U.S."

What are the consequences of non-compliance?

As passengers have undoubtedly heard during their flights, FAA regulations require that travelers adhere to all safety protocols, including those regarding electronic devices.

While it may be challenging for flight attendants to spot whether your phone is set to airplane mode, do you really want to be that person? What will you do next—take off your shoes and walk around barefoot?

Additionally, one of the top reasons to switch off your phone is to ensure you pay attention to the preflight safety briefings, even if you’ve heard them countless times before.

For now, at least, your cell signal won’t function during the flight, so keeping your phone in full cellular mode will only drain your battery—and stop you from binge-watching more episodes of Succession.