In late 2016, Uber announced its unlikely plan to launch an urban flying-taxi service within a decade. Since then, the financially challenged cab company has taken big steps to make that plan more likely. In addition to recruiting staff from places like NASA and Tesla, Uber has signed up aircraft manufacturers to build rooftop-hopping planes, along with a pair of launch cities–Los Angeles and Dallas-Fort Worth–to host test flights beginning in 2020.

But seeing is believing. Today Uber revealed its latest model–a generic design that aircraft makers can use as a starting point for planes that will qualify to run on the UberAir network. The design debuted as part of Uber’s Elevate Summit in Los Angeles this week, where it announces partnerships, and partners announce their progress toward the flying car dream.

The eCRM, as it’s called, is not as sexy as prototypes by Uber rivals, such as the tilting wings of Airbus Vahana or the tilting “electric jets” of Lilium. Uber says its first goals are for passenger safety and comfort, such as wings that shield riders from rain as they board or depart the plane.

Uber’s eCRM is literally two craft in one: a helicopter for vertical takeoff and landing (VTOL) and an airplane for energy-efficient flights between points A and B (no small matter for a battery-powered vehicle).

The craft takes off from (and returns to) compact “vertiports,” such as urban rooftops, like a helicopter. But instead of one giant, loud rotor, it has four sets of smaller rotors mounted high up on the wings. Each set consists of two stacked rotors that spin in the same direction. The top rotor is slightly ahead of the lower one, directing air from one rotor down to the next in a pattern that reduces noise. Quiet craft are challenge number one for a company that wants to run thousands of flights per city, per day, without causing a citizen uproar.

As the craft gets up to altitude (1,000 to 2,000 feet), a propeller mounted high on the back takes over, pushing the vehicle forward so the wings provide lift as the helicopter-like rotors shut down. The energy savings are obvious. While the craft needs four rotors in helicopter mode, just one suffices for airplane mode, flying at a speed of 150 to 200 miles per hour.

Related: How Uber Plans To Get Flying Taxis Off The Ground