Karem Aircraft eVTOL Butterfly tiltrotor, USA.

Overair, Inc.
Lake Forest, California, USA

Overair, Inc. is a spin-off from Karem Aircraft and is located in California, USA. Overair became its own independent company in January 2020 and will be making the production prototype for their electric vertical takeoff and landing (eVTOL) aircraft named Butterfly.

Some background information: Karem Aircraft was founded by Abe Karem in 2004 in California, USA. Ben Tigner was the President and CEO of Karem Aircraft and as of January 2020, is now the President and CEO of Overair. Uber Elevate announced on May 8, 2018 that it was adding Karem Aircraft (now Overair) as one of its aircraft partners to design an eVTOL aircraft for Uber’s Elevate ecosystem.

In July 2019, is was reported that Korean industrial conglomerate Hanwha Systems, pending regulatory approval, will invest $25M in a subsidiary of Karem Aircraft to develop the Butterfly eVTOL aircraft for Uber Elevate’s mission. On Jan. 15, 2020, it was announced that Hanwha Systems was approved for the $25M dollar investment for Karem’s spin-off company, Overair. Hanwha Systems now owns 30% of Overair, Inc.

Abraham E. Karem is regarded as the founding father of UAV (drone) technology.  (Quote from Abraham Karem Wikipedia page.)

Overair’s eVTOL Butterfly aircraft is a very sleek and beautifully designed quad tiltrotor aircraft. The Overair Butterfly uses the company’s patented Optimum Speed Tiltrotor (OSTR) technology which has a far higher system performance (than typical tiltrotors) through integrated improvements in multiple technologies. This includes but is not limited to, variable-speed tilting electric rotors (individual blade control), unique blades, lightweight composites and high efficiency aerodynamics. The Butterfly configuration solves the trade-off between hover and cruise efficiency, creating an optimal vehicle configuration for Uber Elevate’s use case.

The larger slow turning rotor propellers provide more efficient lift, safer flight and the aircraft has quiet acoustics. The larger rotors draw less power from batteries, than aircraft with smaller propellers, which provide an immediate economic impact of making the Butterfly less costly to fly. These propellers also have quieter acoustics which means the passengers will have a quieter ride and urban areas will hear a much quieter aircraft.

According to Overair’s Ben Tigner, using large slow tiltrotors makes the Butterfly a more efficient and faster aircraft on less power. While efficiency sounds academic, efficiency translates into real economic and operational advantages. For example, the Butterfly can fly multiple Uber missions on a single battery charge with a lot of reserve power and it doesn’t need to rely on any exotic power systems. All one needs is batteries. Efficiency also means the aircraft can fly faster from 150 to 200 mph (240 to 322 km/h) , allowing a shorter time period for Uber trips.

Electric motors are quieter and provide a higher margin of safety. High efficiency allows the aircraft to perform well with unexpected wind gusts or unexpected traffic, the aircraft can easily maneuver through these situations where turbine jets or planes might have more trouble.

Overair’s goal is to have their first ridesharing eVTOL aircraft in service by 2023 and having them available for the public for Urban Air Mobility (UAM) by 2025. Overair an Uber Elevate partner. Uber Elevate is the name of Uber’s internal team and initiative focused on launching their Uber Air product for the public. 


  • Aircraft type: eVTOL
  • Pilot: 1
  • Passengers: 4
  • Speed: 150-200 mph (240-322 km/h)
  • Range: 100 miles (161 km)
  • Propellers: 4. A quad tiltrotor with Optimum Speed Tiltrotor (OSTR) technology. A large rotor, slow turning propeller.
  • Electric Motors: 4
  • Power source: Batteries
  • Wing: 1 high wing
  • Tail: 1 V tail.
  • Landing gear: Retractable
  • Energy type: Batteries. All electric.
  • Safety features: Distributed Electric Propulsion (DEP), if one rotor stops for any reason, the aircraft can safely land with the remainding propellers



KaremVectored ThrustInitial DesignElectric/BatteriesVFS Member

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