Popping your phone onto airplane mode is a knee-jerk reaction whenever you board a flight.
Along with stowing your bags, fastening your seatbelt and placing tray tables up, it's part of the ritual of flying.
But what's the point of it? Surely something as puny as your humble smartphone can't actually have an impact on a massive airplane stuffed full of advanced tech?
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Initially, it was all about signal interference - it was thought that because smartphones emit signals in the same frequency band as the airplane's communications and navigations systems, they could potentially interfere with vital apparatus needed for flying.
But this theory was soon debunked, according to Live Science, particularly after the Federal Aviation Administration (FAA) asked an independent body back in 1992 to look at whether people should keep electronic devices on while flying. This body, the Radio Technical Commission for Aeronautics (RTCA), found no interference - which is why we can all happily use our laptops and smartphones while flying.
The real question mark lies over cellular data - which is switched off when you put airplane mode on.
According to American non-profit media site, The Conversation, the problem instead lies with ground interference.
We get data with the help of nearby cell towers - so if everyone in a plane is scrolling through Instagram or chatting on the phone at the same time, all of these extra devices could potentially overload the tower they're flying over. Safe to say you wouldn't be particularly pleased if there was a signal jam, purely because a plane was passing overhead.
Plus, many of our phones are using more advanced tech than ever, particularly as we make the switch to 5G.
Professor Doug Drury, Head of Aviation at CQUniversity Australia, wrote in The Conversation: "The aviation industry points out that the 5G wireless network bandwidth spectrum is remarkably close to the reserved aviation bandwidth spectrum, which may cause interference with navigation systems near airports that assist with landing the aircraft."
So maybe we've come full circle again, and the problem is actually with interfering with the plane signal.
Writing in 2022, Professory Drury said more research needs to be done to really answer the question of what impact our phone signal could have on planes - particularly during vital landings.
Nowadays, flights are increasingly offering in-flight Wi-Fi services, meaning that if you were willing to cough up some cash, you wouldn't have to be disconnected while in the air. Most devices, including iPhones, let you switch Wi-Fi and Bluetooth on, even when airplane mode is on.
Plus, we don't know about you, but we're pretty glad that airplane mode prevents fellow passengers from making loud phone calls for the duration of our flight. We're happy to switch it on, because it's better to be safe than sorry, but it also affords us a bit a peace and quiet while traveling.