In 1961, Hughes was one of the twelve companies that submitted proposals to meet U.S. Army TS-153
requirement for a four-seat turbine-powered light observation helicopter. Model 369 was developed
and flew first on 27 February 1963. Five machines of this type were ordered as OH-6A for the
evaluation programme. The OH-6A Cayuse powered by an Allison T63-A-5A turboshaft was the winner of
the U.S. Army's contest in May 1965. Deliveries commenced in September 1966 to meet an initial
three-year commitment for 1071 machines. Next to the military OH-6A Hughes developed a larger,
five-passenger civilian version. Initially designated as the 369H and 369A during the development stage,
it emerged on the market as the Hughes 500. In 1968, the 500C with the more powerful Allison 250-C20
engine was introduced. In 1977, the 500D entered the market with a new five-bladed rotor system and the
Allison 250-C20B engine. In 1982, Hughes introduced both the 500E with the Allison 250-C20B and the 530F
with the more powerful Allison 250-C30 engine. On 6 January 1984, Hughes Helicopters became a subsidiary
of McDonnell Douglas, and subsequently re-designated the McDonnell Douglas Helicopter Company.
The Hughes 500 thus became the MD500.
Flygjänst' MDHI MD-369E SE-HNZ visited the Heli-Holland heliport near Emmen in the Netherlands when
on delivery from Sweden to the UK. The 1985-built MDHI MD-500E was registered first in
Norway as LN-OMV. On 26 June 1987, the MDHI MD-369E was registered SE-HNZ in Sweden with SAAB Helikopter AB. In 1988, the MD-500E
was sold to the Vilhemina-based Flygtjänst AB in the southern parts of Lappland county and registered with F.J. Viklund, Vilhelmina, Sweden, on 29 March 1988.
After delivery of the SE-HNZ at Sywell, registration SE-HNZ was cancelled on 16 June 2006. On 28 June, the MD-500E was registered G-RISK in the UK
with Wavendon Social Housing Ltd., Bedford.