The Mobile Dead Zone on Airplanes

Cell reception is bad after boarding because of the way airports are designed.

Skaman306 / Getty

You stow your bag, settle into your airline seat, and begin swiping away at your phone until takeoff. The signal is sluggish, and the bars of service blink between one and none. Twitter feeds don’t load, email struggles to come through, and texts hang unsent. It’s frustrating—there’s still work to be done, or loved ones to be updated on your progress. But it’s also confusing. The signal was fine just moments ago, in the terminal.

Cellular reception is uniformly awful on airliners parked at gates. But why? The most obvious answers are vaguely conspiratorial: Maybe interference from the wiring or circuitry in the aircraft fuselage plays a part. Or perhaps a magic box in the cockpit somehow interrupts service to dissuade in-flight use. I wondered if a governing body like the Federal Aviation Administration might require airports to dampen cell signals, or if some carriers were affected more than others.

I asked three commercial pilots (two from Delta, one from British Airways), and all of them agreed that cell reception is particularly bad at this odd juncture pre- and post-flight—for pilots as well as for passengers. “There are certain areas of ramps and jetways where our ACARS uplinks are sketchy for the same reason,” one of them, Mark Werkema, told me. ACARS stands for “aircraft communications addressing and reporting system”; airplanes use it to communicate with one another and with control towers. It would seem like a safety concern if bad coverage affected important communications sent or received by the crew.

Jon Brittingham, a technical pilot in the Airbus A319/320/321 program, explained the causes to me in greater detail. Older aircraft, such as the McDonnell Douglas MD-90, don’t have the same electronic-systems shielding to protect cabin equipment from third-party signals that more modern airliners, such as the current Airbuses, have. In fact, this shielding is most dense around the front of the cabin—thus confirming my pilot friends’ agreement about poor reception within the cockpit. (This same fact can also cause cell reception in first-class seats to be the worst in the plane, when parked by the gate.)

Airports are giant swaths of empty space where large vehicles exit and enter the sky. That makes them poor candidates for cellular-antenna towers. Towers might grace the airport’s edges, but the expanse of airfields, and the distance to the terminals, makes coverage a stretch. To compensate, airports use distributed antenna systems (DAS): small, targeted cellular-access points (some barely bigger than smoke detectors) that work particularly well in indoor, controlled spaces. A DAS provider explained the particular challenge of airports: “These spaces are often challenging topologies that have high ceilings, wide-open areas or are located in harsh environments that present a challenge to designing and deploying reliable wireless service.” Harsh environments—what a nice euphemism for the sound and fury of terminals.

It works, indoors at least. The Denver International Airport, for instance, has been lauded for its use of DAS networks to provide superior service to passengers in the terminal and throughout the concourses—even better than customers are used to at home in the suburbs. But once you’re sitting on the plane, the signal problems begin. As Wired reported several years ago, that may have to do with conflicting signals caused by the plethora of small cellular antennae inside the terminal and the cell towers beyond the air field. (There’s also onboard Wi-Fi, further complicating things. That’s another issue, but one more reason, as a Delta ad put it, we’ve come to “expect the internet” when flying.)

Basically, on the plane your phone can’t decide which antenna to connect to, and this confusion contributes to the slow service. It doesn’t help that on any given plane, anywhere from 50 to 300 passengers might be clambering for a signal as soon as they are seated or as soon as the plane touches down. Pair this with certain aircraft models, such as the Boeing 787, whose structural materials may impede cell signals, and you get a perfect storm of poor service.

A coverage rift erupts most noticeably between the terminal’s interiors and the surrounding cellular landscape. On the airplane, you’re neither inside the airport nor clearly outside it—you’re in a bizarre netherworld, where cell signals are muddled.

Bad service on parked planes becomes a useful parable for thinking about the overlapping promises of mobile technology and commercial flight. You want to think of yourself as standing at the center of the travel experience: it’s your journey, your life, your social-media posts. But complex infrastructure and collective behaviors make the whole enterprise chug along. To provide maximum service to users, carriers oversupply the airport concourses, but at the expense of the tarmac areas that fall just out of reception zone for the terminal antennae, which are also just a bit too far from nearby cell towers. It’s a compromise in service of a larger (if imperfect) arrangement.

When cell signals go dark on the plane after boarding, it’s a low-grade reminder of how air travel is woven into people’s lives on the ground. Landing passengers need to communicate with family, friends, or drivers arriving for pickup; urgent work tasks may need attending to. An ongoing “searching” icon can be infuriating. It seems like these are two separate realms and they should connect more discretely, yet also seamlessly. But the truth is, flight is always messily entangled with infrastructure on the ground.

That’s an anxiety that pervades airports, places where connections of all kinds get made and broken. There’s a reason the China Philharmonic Orchestra staged a flash performance at Beijing Capital International Airport in February: It was sure to be captured by phone and shared online, thanks to saturated DAS antennae. The recent Hong Kong airport protests were effective because they interrupted the traffic (and thus economic) flows around the huge site—but just as much because these interruptions were disseminated via smartphones. When Newark airport was suddenly and terrifyingly evacuated in September, the chaotic scene was uncanny not just for what it was (or wasn’t), but for how it quickly dominated social-media feeds far beyond the New York region. Live shooters and terrorists preoccupy Americans’ minds, and the airport was ready-made for an incident of this type.

Everyone is on edge at the airport. Will I make my flight? Am I a bad parent for traveling to make a living? Can I afford this vacation? That makes it even more irritating when something seemingly simple, like mobile coverage, breaks down. But maybe the uncertainty causes most of the anxiety. Flyers are worried about what they cannot control. In the face of ignorance, any knowledge is a comfort: You’re definitely going to miss your connection; or you saw your bag being loaded onto the plane.

When the specter of bad coverage takes your pre- or post-flight calls and app updates out of commission, take it as another new certainty: There’s nothing you can do but wait. It’s not about you anymore, but an accident of infrastructure. Flyers might take this moment as a chance to feel humility rather than self-centered frustration. Look around, and appreciate the complexity of the system at work. Appreciate that it works as well as it does, most of the time. Instead of searching for a cell signal (or an email, or an Instagram update), look for a signal of a different kind. Everything’s going to be okay—and, for now, there’s nothing you can do about it anyway.