Do You Actually Need To Use Airplane Mode?

On this page:

• What does airplane mode actually do? ↓
• Why do airlines ask you to turn on airplane mode? ↓
• What happens if you don’t use airplane mode? ↓
• Can your phone really interfere with an airplane? ↓
• FAQ ↓

Airplane mode disables all cellular signals and wireless transmission so you can’t receive text messages, make calls, or use any apps that require an internet connection.

You can toggle some of those signals back on, like Wi-Fi or Bluetooth, while still keeping cellular off.

Airplane mode is largely a precautionary exercise to eliminate any possibility of interference with radio signals, communications, and other systems the plane uses during the flight. Officially, the Federal Aviation Administration (FAA) states there is potential interference between portable electronic devices and the aircraft’s navigation and communication systems.

Limiting cellular signals can also help keep people attentive to on-board communications, safety instructions, and potential emergency situations – especially during takeoff and landing.

“There is a safety concern, but it's not what people expect,” said Thomas Inman, author and retired professor of avionics at Pennsylvania College of Technology. “I'm sure you are aware of how easily one can get mesmerized by the small screen — the crew wants your full attention.”

The real impact of skipping airplane mode is actually happening on the ground. When your phone is searching for a signal in the air, it sends a higher amplitude signal in an effort to make a connection. These loud signals can blast cell towers in the flight path and drown out signals on the ground.

“Cellular systems are designed for terrestrial use, so being thousands of feet in the air can create conditions that ground networks aren't optimized to handle,” said Justin Crabbe, commercial pilot and founder of private jet charter companies, Jettly and BlackJet.

You may successfully get a spotty signal if the plane is low enough. But at high speeds and altitudes, your phone’s frantic attempts to search for a connection can cause congestion and noise for cell towers on the ground.

Nothing. If you forgot to turn on airplane mode, the most likely inconvenience is draining your battery.

If phones were capable of interfering with the safety of a plane in a significant way, airlines wouldn’t rely on the honor system and the occasional announcement for you to turn on airplane mode.

That said, the precaution is in place for a reason, and it doesn’t hurt to comply.

“One forgotten phone won't be too risky, but it's not always safe to assume that isolated risks are harmless,” said Crabbe. “Everyone on board should still follow instructions and protocols to control and mitigate risks and make sure everyone maintains the same safety standards.”

Planes are designed to block interference that could disrupt their instruments. In fact, the FAA recently mandated that all aircraft radio altimeters be upgraded to tolerate any potential 5G network interference, despite debate about the threat level of such signals. This rule targets ground-based 5G towers, rather than phones. 

“Aircraft systems are shielded, redundant, and certified with wide margins, so not every phone poses a direct threat,” said Crabbe. “While aviation relies on multiple layers of protection, it's always sensible to minimize unnecessary interference on board.”

That said, the “noise” of your phone attempting to send a signal can create annoying headset interference for pilots in the cockpit. One or two phones not using airplane mode could go unnoticed, but a plane full of frequency disruptions would make communication difficult.