Uber may already be investing on self-driving cars in Pittsburgh, but it looks like the company is looking beyond just providing rides on land. Uber products head Jeff Holden has said that they are currently looking into short-haul flying vehicles for transporting passengers.

The technology that Holden is referring to is called VTOL, which stands for vertical takeoff and landing. VTOL is an aircraft that functions similarly to helicopters — it can hover, take off and land vertically. The major difference between VTOL and a helicopter is that the former comes with multiple rotors and have wings. A VTOL is also similar to commercial drones and can also be piloted autonomously, according to TechCrunch.

Uber has been researching on VTOL “so we can someday offer our customers as many options as possible to move around,” Holden told Recode. Holden also appears to be optimistic about the technology stating that it could be available to customers within a decade.

He imagines that such an aircraft could transport multiple passengers on short-haul flights, according to CNET. The product head also noted that its self-driving cars were conceptualized just a few years ago and is now being rolled out in Pittsburgh.

The problem with Holden’s statement that VTOL could be in use within the decade is that, flight navigation is far more complex compared to land transportation. There’s always a risk of mid-air collisions which could potentially put people on the ground in danger. There’s also the question of regulatory issues. Camera-equipped drones are already getting a lot criticisms, and it wouldn’t be a surprise if the same thing happens with Uber’s plans.

Majority of VTOL research has been conducted by the military like DARPA, the United States defense agency responsible for developing new technologies. DARPA is already working on what’s being called as the VTOL Experiment Plane (VTOL X-Plane) program with the goal of improving vertical and cruising flight capabilities.