Overair has doubled the size of its California headquarters as it steps up efforts to bring its Butterfly eVTOL aircraft to market in 2026. The new facilities in Santa Ana consist of a pair of buildings, respectively 94,000 sq ft and 109,000 sq ft in area, encompassing offices, shop lab space, and clean rooms for aircraft design, development, and manufacturing, as well as separate areas for systems integration work and testing.
According to the company, the expansion of its premises near John Wayne/Orange County Airport has been timed to coincide with its transition from the design phase of the Butterfly program to certification and scaled production. In a November 4 announcement, it said that it intends to hire around 1,000 employees over the next three to five years, including aerostructures and propulsion systems engineers.
The program timeline calls for a full-scale Butterfly prototype to start flight testing by 2023 en route to FAA Part 23 type certification by the end of 2025. In 2022, the company plans to fly an initial prototype.
Overair has started ground testing a full-scale propulsion system, including the 20-foot-diameter rotor system. It is also working with prospective suppliers and partners to agree on how they will contribute to the program.
According to Overair, the Butterfly will be able to carry five passengers plus an unspecified amount of cargo on trips of over 100 miles. It is expected to have a top speed of 200 mph and be able to operate in IFR conditions.
The aircraft’s performance is based on the patented Optimum Speed Propulsion system developed over the past couple of decades through a sequence of rotorcraft and drone designs developed by company founder Abe Karem. Its four large tilting propellers spin slowly in hover and even slower during cruise flight, which Overair says results in reduced power consumption that boosts payload, as well as safety margins for operating in challenging environmental conditions. The high aspect ratio wings have full-span flaps to support low stall speeds.
The large blade area of the propellers, combined with their slow rotation speed and low disk loading, will minimize pressure disturbance, which is also expected to deliver low noise by comparison with both helicopters and other eVTOL designs. According to the company, the noise level at hover (measured at a distance of 100 meters) is estimated at 55 dBA, while at cruise (measured at 500 meters) should be around 30 dBA.
“This new office space helps us to promote a culture that allows everyone on the Overair team to achieve their personal goals and the company’s vision of making the world a smaller, cleaner place,” said Overair CEO Ben Tigner. “This expansion enables us to grow our talented team, add hundreds of jobs to our community, and accelerate Butterfly’s introduction as the most robust and quietest electric vertical lift aircraft in its class.”
To date, Overair has received $25 million in financial backing from its Korean partner Hanwha Systems. In January 2020, it was spun off from Karem Aircraft and now operates as a separate company, with plans for further fund-raising.