An old Black Hawk helicopter took off in West Palm Beach, Florida on May 29. Black Hawk helicopters, the famous aircraft used by the US Army, have been flying for decades—and while this craft looked normal on the outside, there was something very different about its guts: Helicopter-maker Sikorsky had installed the first part of a system that may someday allow these workhorse choppers to fly completely on their own.

The flight marked the first time that Sikorsky had tested the precursor for this Black Hawk autonomy system in the air. The set-up was a simpler version of an autonomous flight system called Matrix that the company has already been testing in another helicopter, known as the Sikorsky Autonomy Research Aircraft, or SARA. It can already do futuristic things, like fly itself from one point to another after a pilot tells it to using an input device as simple as a tablet. And like a self-driving car, it has sensors on the outside to perceive its environment.

This Black Hawk is more than 40 years old, but nonetheless has what Chris Van Buiten, a vice president at Sikorsky Innovations, describes as the “foundational elements” of the autonomy system. The idea is that future Black Hawks, which traditionally have two pilots, could “fly with two crew, one crew, or zero crew depending on the mission demands,” he says. They plan to have the same old Black Hawk completely fly itself in 2020 for the first time.

The concept behind creating this system is straightforward: to give the pilots a break from actually flying the helicopter. That might sound strange, but in a complicated or dangerous mission, taking the workload involved in controlling the helicopter away from the pilots could help them focus on big-picture planning. Plus, a Black Hawk schlepping cargo on a mundane, boring mission, or doing something very dangerous, could just fly itself with no humans on board.

The component that Sikorsky added to the test Black Hawk is called a fly-by-wire system, which dramatically differs from the normal way a Black Hawk is built. In a typical Black Hawk, there is a mechanical connection (thanks to elements like pushrods and cables) between the controls the pilot uses to fly the helicopter and the spinning rotors. That mechanical system as well as hydraulics controls the pitch of the blades.

With fly-by-wire aircraft, like a Boeing 787 Dreamliner or an F-16 fighter jet, the connection between the controls the pilots uses and the surfaces on the outside of the planes is digital; computers sit between the two elements. Fly-by-wire is like pushing a button that’s connected via an electric circuit to a motor that opens a door for you, while non-fly-by-wire would be like pulling that door open directly with a string, perhaps with the help of some pulleys.

To make a helicopter autonomous—to tell it what to do with software—the aircraft needs to have a fly-by-wire system. “[It’s] pretty neat that one of the oldest Black Hawks has by far the most advanced control system,” Van Buiten says. “We did that to show that we could retrofit any of the Black Hawks.” The Army is also working on adding a Sikorsky autonomy system onto a much newer Black Hawk.

And broadly speaking, this same kind of autonomy technology can help make a future where easy-to-fly electric air taxis help whisk people from place to place around and near cities.

Check out the old Black Hawk’s first flight, below.