Facebook on Tuesday said it will stop building pilot-less planes designed to beam down internet from the sky.

It was one of a few web companies that set out a few years ago to bring connectivity to areas where it was lacking. That approach could have the effect of bringing on more users and driving revenue growth. Google parent Alphabet has rolled back its Titan internet drone program, although it still has Project Loon, which relies on large balloons.

Facebook began its Aquila internet drone program in 2014, as part of its internet.org initiative.

“Aircraft like these will help connect the whole world because they can affordably serve the 10% of the world’s population that live in remote communities without existing internet infrastructure,” Facebook CEO Mark Zuckerberg wrote in a post on the social network in 2015, when the company said it had run its first flight of the Aquila drones in the United Kingdom. Another test flight followed.

The project involved lots of investment.

“To increase our chances of success we took on every part of our aircraft’s design, development, and testing, work that was led by our team in Bridgwater, UK,” Facebook engineering director Yael Maguire wrote in a blog post on Tuesday.

Maguire said the company made technical progress. It set records for quickly transferring data wirelessly.

But industry as a whole has evolved since Facebook and Google set out on the project.

“As we’ve worked on these efforts, it’s been exciting to see leading companies in the aerospace industry start investing in this technology too — including the design and construction of new high-altitude aircraft,” Maguire wrote. “Given these developments, we’ve decided not to design or build our own aircraft any longer, and to close our facility in Bridgwater. Going forward, we’ll continue to work with partners like Airbus on HAPS connectivity generally, and on the other technologies needed to make this system work, like flight control computers and high-density batteries.”

Facebook has also started other connectivity initiatives, like an industry group focused on improving telecommunications equipment, and may be planning to launch satellites to deliver internet connectivity, based on a job listing that appeared earlier this year.

Earlier on Tuesday Business Insider reported that Andrew Cox, head of the Aquila program, had left Facebook.

Facebook continues to hire people to work on maps for humanitarian efforts.