Why you can't get cell service on the tarmac

While just about everyone knows to turn their cellphone off or on airplane mode once the plane takes off, there’s no rule against using it while your plane is on the ground. But we’ve probably all faced the struggle of trying to use our phones on the airport tarmac, only to get caught in an endless loading cycle.

I’ve experienced it personally on many occasions. I’ll want to send a quick text to friends or family to update them that I’m about to be unavailable for a bit. Or I’ll remember last minute that I wanted to download an episode of the Netflix show I’m currently bingeing for the flight. But more times than not, I’m unable to get a stable connection.

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As it turns out, there’s a reason why you may experience difficulties with your cellular connection while on the tarmac. Christopher Schaberg from The Atlantic recently investigated the cause of the “mobile dead zone” on airplanes and found that it’s actually due to how airport terminals and some planes are designed.

Schaberg calls airports “giant swathes of empty space where large vehicles exit and enter the sky.” This makes those areas poor candidates for cell towers. Instead, cell towers are generally only located on the outskirts of the airport. With so much space between the cell towers and the terminal areas, coverage can be challenging.

Most airports combat this with distributed antenna systems (DAS), which are small, targeted cell-access points that can extend the coverage area without needing a large cell tower to be erected in the middle of the airport. However, even these systems have their limitations. DAS systems work best in indoor, controlled spaces. Open-spaced terminals with high ceilings, large airfields and airport tarmacs filled with moving planes and other vehicles do not exactly fit into that definition.

While your phone might do OK while in the terminal (in fact, some airports like Denver International Airport have a reputation for having great cell service within the terminal), things get even more complicated once you board.

Once you’re on a plane, you’re farther away from the DAS systems in the terminal and closer to the larger cell towers that are located on the outer edges of the airport. Add in on board Wi-Fi systems, and your phone can easily get confused as to which antenna its meant to connect through. Of course, being inside a metal tube certainly doesn’t help service quality either.

Jon Brittingham, an Airbus A319/320/321 pilot, told Schaberg that electronic-systems shielding protects cabin equipment from third-party signals in more modern airliners. This just adds another reason why your phone may not want to establish a stable connection while you’re stuck on the tarmac. Because these systems are located at the front of the plane, it also means pilots and first-class passengers may struggle even more with getting a secure connection.

Also, keep in mind that aircraft models are designed with structural materials that hinder cell signals. For example, Boeing 787s reportedly use wire rebar for structural integrity, which can interfere with cell signals on the plane.

Between the suboptimal layout of airports and terminals to support standard cell tower systems, the complications of DAS systems covering the tarmac and the planes themselves sometimes hindering signals, it’s no wonder I can rarely manage to get Spotify to download a new song before take off.

Bottom line 

With this reasoning, it makes more sense why finding a connection on the tarmac is so much harder when flying out of larger airports. I struggle to get my phone to do much of anything when I’m on the tarmac at DFW or DTW (both of which are two of the largest airports in the U.S. based on land area), but it’s not much of a problem when I fly out of the much smaller Clinton National Airport (LIT) back home in Arkansas.

While there isn’t really anything you can do to make your cell connect more reliably while on the tarmac, you can help prevent frustrations caused by not being able to connect. Make sure you’re taking care of important calls, emails and text updates while you’re still in the terminal. Double-check to make sure you have all of the Netflix, Hulu or Disney+ movies and shows you want for the flight before you board, too. Personally, I always fly with a book because I know my cell coverage is always spotty. That way I have something to keep me occupied between when we board and when in-flight Wi-Fi becomes available after takeoff.

Madison Blancaflor

is a full-time contributor for TPG, covering all things credit cards.

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