Uber announced on May 8, 2018 that it was adding Karem Aircraft as a partner. The Karem Butterfly uses the company’s patented OSTR technology, with four variable-speed tilting electric rotors.
From the Karem website:
Karem Aircraft develops and manufactures advanced fixed-wing and rotary-wing aircraft, including manned and unmanned high-efficiency tiltrotors. Karem’s patented Optimum Speed Tiltrotor (OSTR) technology combines the fast, inexpensive, safe operation of efficient fixed-wing airplanes with the robust hover capability of helicopters. Our team of world-class engineers, technicians, and professionals work to create innovative vehicles and improved mobility, including best-in-class rotorcraft and aircraft solutions for commercial and military markets. The company is headquartered in Orange County, California, with offices in York, Virginia and Victorville, California.
Karem Aircraft was founded by Abe Karem in 2004. Karem Aircraft is a participant in the US Army’s Joint Multi-Role Technology Demonstration (JMR TD) program. Other recent Karem contributions include work on DARPA’s VTOL X-Plane (VXP) program and DoD’s Joint Heavy Lift (JHL) and Joint Future Theater Lift (JFTL) programs. Several privately funded initiatives are also underway at Karem, including development of the AeroTrain® and AeroCommuter® Optimum Speed Tiltrotors intended for commercial passenger transportation.
Prior to founding Karem Aircraft, Abe Karem founded Leading Systems and Frontier Systems. Leading Systems developed the Amber and GNAT 750 (predecessors of the General Atomics MQ-1 Predator). At Frontier Systems, Abe led the development of Optimum Speed Rotor (OSR) technology and unmanned aerial vehicle (UAV) systems, as well as the A160 Hummingbird Optimum-Speed Rotor UAV, now owned by Boeing.