Google co-founder Larry Page in 2010 teamed up with self-driving car pioneer Sebastian Thrun to form Kittyhawk (initially Zee.Aero), a startup company with the aim of developing affordable, efficient, fully autonomous aircraft that could be used to transfer passengers across major cities in minutes, instead of hours the same traffic-filled routes would take by car.

Despite some successful test flights with various prototypes over the years, Kittyhawk announced on Wednesday via social media it is winding down. It also said it is evaluating what will happen next, suggesting the company or perhaps its employees will have a new focus at a later date.

Kittyhawk's main focus was the Heaviside, a model resembling a conventional aeroplane but with rotating propellers to enable vertical take off and landing (VTOL). It was powered by electric motors to help keep noise levels low, and prototypes were able to reach speeds of 180 mph and cover 100 miles on a charge. The company also demonstrated a prototype that could take off, fly, and land autonomously.

Kittyhawk also developed a single-seat, VTOL multicopter called the Flyer, which had manual controls. However, at a weight of just 250 lb, it fell into a category of aircraft that doesn't require a pilot's license, meaning it could be flown by just about anyone. However, the company abandoned plans for the Flyer in 2020.

Kittyhawk also had a model called the Cora, which was similar to the Heaviside. However, the Cora in 2019 was transferred to a joint venture between Boeing and another startup called Wisk Aero, and its development is ongoing. A spokesperson for Boeing told CNBC that Kittyhawk's decision to wind down won't affect Wisk Aero's operations.