Boeing X-50 Dragonfly

The Boeing X-50 Dragonfly is an unmanned, out blank as convertiplane experimental aircraft of the U.S. manufacturer Boeing and DARPA to demonstrate the viability of a rotor concept. The total amount of the order, initiated in 1998 for two flying prototypes was 24 million U.S. $, of which Boeing and DARPA over each took half.

The unmanned aircraft can take off vertically like a helicopter, but in forward flight, the rotor can be stopped and then acts like a conventional wing. For landing it is set again in rotation. The machine has canards and horizontal tail in the rear, which also carries the double rudder. All three areas have a similar span.

The first flight took place on 24 November 2003. During the third flight on 23 March 2004, the plane crashed. It then another, improved prototype was made ​​, who made a first short flight on 4 November 2005, but on 12 April 2006 crashed again and was completely destroyed. The testing program included 11 flights.

The rotor has a cold blade tip drive. The drive is effected by a turbofan engine, the air flow is used for both the forward flight as well as to the rotor output shaft. During the hover it provides additional control nozzles.

The development is based on experiences that have been made with the Sikorsky X-wing.