MD 500 Defender American Light Multi-Role Helicopter

The McDonnell Douglas Helicopter Systems MD 500 Defender is a light multi-role military helicopter based on the MD 500 light utility helicopter and OH-6 Cayuse Light Observation Helicopter. The Defender 500 foreign military sales helicopter is offered with either a four- or five-blade main rotor, depending on the model, with a weapons platform mounted on the lower rear body. This light utility commercial helicopter could seat five passengers in comfort, and is used mainly by the military, being very flexible and offering good all round capabilities. Other missions include: direct air support, antitank, reconnaissance, observation, and light utility. A single engine is mounted inside the body with air intakes on top of the cabin and a black hole exhaust. The fuselage is teardrop-shaped a features a round, glassed-in cockpit and landing skids. External stores are mounted on weapons racks on each side of the fuselage. Each rack has one hardpoint. The tail fin is boomerang-shaped, swept-back, and tapered. The tail flats are back-tapered with small fins attached to the tips, with the flats high-mounted on the fin forming a T. The rotor is mounted on the lower left of the tail boom. The successful Hughes 500/MD 500 series began life in response to a U.S. Army requirement for a Light Observation Helicopter (LOH). Hughes' Model 369 won the contest against competition from Bell and Hiller. The subsequent OH-6 Cayuse first flew in February 1963. The 500 series design features shock-absorbing landing skid struts, a turboshaft engine mounted at a 45-degree angle toward the rear of the cabin pod, a fuel tank cell under the floor and the battery in the nose. The engine exhaust port is located at the end of the cabin pod underneath the tailboom. It has a short-diameter main rotor system and a short tail, giving it agile control response and is less susceptible to weather-cocking. Hughes won the U.S. Army's LOH contest with its OH-6 helicopter by submitting a very low and aggressive price per airframe (without an engine). Due to rising prices, the U.S. Army later re-opened the contest, where Hughes offered the machine at a more realistic price, but was undercut by the redesigned Bell OH-58 Kiowa (military JetRanger). OH-6 helicopters were still ordered by the U.S. Army, though at a much reduced number. Prior to the OH-6's first flight, Hughes announced it was developing a civil version, to be marketed as the Hughes 500, available in basic five- and seven-seat configurations.[3] A utility version with a more powerful engine was offered as the 500U (later called the 500C). The improved Hughes 500D became the primary model in 1976, with a more powerful engine, a T-tail, and a new five-blade main rotor; a four-blade tail rotor was optional. The 500D was replaced by the 500E from 1982 with a pointed nose and various interior improvements, such as greater head- and legroom. The 530F was a more powerful version of the 500E optimized for hot and high work. McDonnell Douglas acquired Hughes Helicopters in January 1984, and from August 1985 the 500E and 530F were built as the MD 500E and MD 530F Lifter. Following the 1997 Boeing-McDonnell Douglas merger, Boeing sold the former MD civil helicopter lines to MD Helicopters in early 1999. Military variants are marketed under the MD 500 Defender name.