While boarding an airplane, I always glance inside the cockpit. Lately, I’ve noticed something different: Instead of reams of paper in binders, the pilots all have iPads slung in holders affixed to the windows.

It’s not a glamorous part of the job, but all pilots depend on paperwork to fly. Every single flight, pilots used to lug 35 pounds of aeronautical charts and flight manuals with them into the cockpit. They’d tuck the thick binders here and there inside the cockpit, not the roomiest of work environments to begin with. “The worst part was schlepping around your flight-kit bag everywhere,” says American Airlines pilot Tim Raynor. “International flights were the worst. You’d have to have new data for every country you were going to. That means even more binders.”

The weight of the paperwork was so heavy it was cutting into the bottom line. Maya ­Leibman, American’s chief information officer, says hauling that extra weight cost $1.2 million a year in jet fuel. The tablets ended that waste. “We went from 35 to 40 pounds to about 1.5 pounds,” she says. “It’s definitely a good return on investment.”

And keeping those books updated was very time consuming. The Federal Aviation Administration, airports and other aviation entities are constantly issuing reports and alerts about changing conditions. A new cellphone tower, runway work, radio-frequency changes — all of this data needs to be updated on a regular basis. Before the iPad, pilots did this by hand. “We’d take out between 100 and 400 pages,” Raynor says. “Imagine 3,000 pilots all doing this twice a month, every month.” The use of a tablet saves 24 million printed pages every year, Leibman says.

American is the first airline to receive ­Federal Aviation Administration approval for tablet use during all phases of flight. This is an opportunity to load the iPad with apps, but pilots won’t be playing Angry Birds or watching Game of Thrones. Instead, their iPads are stocked with more information than is available via the airplane’s flight systems.

For example, most commercial cockpit-navigation systems display only a few other airports along the flight route that a pilot can head ­toward during an emergency. “Now, with the tap of a finger, we can see all of them,” Raynor says. One useful app helps pilots calculate crosswind limits during takeoff. And weather apps provide detailed information about changing conditions.

Once you’re looking for them, tablets are all over our operations. Flight attendants have replaced the bulky, custom-made credit card readers — nicknamed “the brick”— with tablets with credit card readers. The FAA is now validating the installation of their ­manuals on the devices as well, Leibman says. Line maintainers who work on the aircraft parked at gates also have tablets at their disposal. Now that they have all the airplane’s schematics in one place, they can search through thousands of pages almost instantly and share photos or questions with an engineering help desk.

The airline is not immune to the plague that afflicts individual customers — obsolescence. “By the time we procure and distribute them, the devices can be out of production,” Leibman says. As frustrating as this could be, it’s also an opportunity to improve the capabilities of the tablets, including lower weights and greater security.

Most people think of the revolution in ­mobile electronics in terms of the movies and games they can enjoy in their seats. But the humble tablet is doing more than fending off in-flight boredom; it’s reinventing the flight experience — for pilots, customers and the maintainers. Not bad for something ­skinnier than a daily newspaper.