The vehicle, which is claimed to be a four-seater, makes use of four ducted fan rotary engines that are encased in repositionable nacelles. In 2003, the Skycar hovered for a short period of time while tethered to a cable suspended from a crane. Moller claims that it has since made several additional tethered hovers. A promised manned, untethered flight has been scheduled and canceled on numerous occasions over the years but has never been attempted. The company says it has spent around $100 million over that time to develop its craft.