folded. The wings unfold while in free-fall, and he then can fly horizontally for several minutes, landing with the help of a parachute. He achieves true controlled flight using his body and a hand throttle to maneuver; jet wingsuits use small turbojets, but differ from other aircraft in that the fuselage and flight control surfaces consist of a human. The system is said by Rossy to be highly responsive and reactive in flight, to the point where he needs to closely control his head, arm and leg movements to avoid an uncontrolled spin. The engines on the wing must be aligned precisely during set-up, also to prevent instability. An electronic starter system ensures that all four engines ignite simultaneously. In the event of a spin, the wing unit can be detached from the pilot, and pilot and wing unit descend to Earth separately, each with a parachute. Since 2007, Rossy has conducted some of his flight tests from a private airfield, Skydive Empuriabrava, in Empuriabrava (Girona, Costa Brava), Spain. Rossy's jet pack was exhibited on 18 April 2008 on the opening day of the 35th Exhibition of Inventions at Geneva. Rossy and his sponsors spent over $190,000 to build the device. His first successful trial flight was on 24 June 2004 near Geneva, Switzerland. Rossy has made more than 30 powered flights since. In November 2006 he flew with a later version of his jet pack. On 14 May 2008 he made a successful 6-minute flight from the town of Bex near Lake Geneva. He exited a Pilatus Porter at with his jet pack. It was the first public demonstration before the world's press. He made effortless loops from one side of the Rhone valley to the other and rose . It has been claimed that the military was impressed and asked for prototypes for the powered wings, but that Rossy kindly refused the request stating that the device was only intended for aviation enthusiasts. On 26 September 2008, Rossy successfully flew across the English Channel from Calais, France, to Dover, England, in 9 minutes, 7 seconds. His speed reached during the crossing and was when he deployed the parachute. Since then he has—in several flights—managed to fly in a formation with three military jets and cross the Grand Canyon, but he failed to fly across the Strait of Gibraltar—he made an emergency landing in the water. Rossy appeared in