McDonnell-Douglas MD-600 / MD-630
On 8 November 1994, McDonnell Douglas announced their plans to develop an eight-place version of their popular MD520N helicopter. They surprised the world's press in January 1995 when they flew their new helicopter to Heli-Expo 95 in Las Vegas, Nevada. The prototype, then known as MD 630N (N630N, converted from MD 530F demonstrator), first flew 22 November 1994, 138 days after project approval. After their public debut at Heli-Expo the first year's production was sold out on the first day.
Production go-head was given on 28 March 1995, at which time designation changed to MD 600N; and a prototype was first flown with production standard engine and rotor system on 6 November 1995.
The 600N has a 33in lengthened fuselage centre section with double, centre opening doors, which gives access to a six-foot long flat floor with seating for five passengers in this rear cabin and three across the front seats. The complete fuselage of these helicopters are built under contract by helicopter manufacturer Kaman Aerospace. The six bladed fully articulated main rotor system shares many components with the MD500 series machines, and power comes from an 800-shp Rolls-Royce Allison 250-C47M turboshaft engine, which is derated to 600 shp for take-off and 530 shp for maximum continuous. The engine is equipped with FADEC as well as a manual backup hydro-pneumatic fuel system.
Production prototype (N600RN) first flown 15 December 1995, and became certification test vehicle leading to FAR Pt 27 certification, but was destroyed in ground fire 28 May 1996, following emergency landing after rotor/tailboom strike during abrupt control reversal tests. This resulted in changes to tailboom/rotor clearance; third prototype (N605AS) flown 9 August 1996; further accidents to N630N on 4 and 21 November 1996 and on 18 January 1997, all during autorotational descents, culminated in total loss and delayed certification and first delivery, originally scheduled for 18 December 1996, to 15 May and 6 June 1997, respectively. MD 600N certified on MD500 certificate.
The 630N features a stretched MD 520N airframe (less than 1% new parts) by means of 0.76m plug aft of cockpit/cabin bulkhead and 0.71m plug in tailboom, combined with more powerful engine, uprated transmission and six-blade main rotor. Cabin has flat floor to assist cargo handling, and will feature quick-change interior configurations to suit multiple-use operators. Intended for civil, utility, offshore, executive transport, medevac, aerial news gathering, touring, law enforcement and other noise-sensitive operations; also adaptable for armed scout, utility and other military missions.
Powered by one 603kW Rolls-Royce 250-C47M turboshaft, derated to 447kW for T-O (5 minutes) and 395kW maximum continuous, with FADEC. Transmission manufactured from WE43A magnesium alloy for lower weight, greater strength and enhanced corrosion resistance, rating 447kW. Fuel contained in two crashworthy bladder tanks in lower fuselage, total capacity 440 litres, of which 434 litres are usable.
The electrical system comprises 28V 200Ah starter-generator and 28V 17Ah Ni/Cd battery. 24V auxiliary power receptacle inside starboard cockpit door standard.
In July 1998, Boeing completed a year-long envelope expansion programme for the MD 600N leading to FAA approval for operation at a density altitude of 2,135m at a T-O weight of 1,746kg and at a density altitude of 1,220m at a T-O weight of 1,860kg. Other performance enhancements approved by the FAA included provision for doors-off operation at speeds up to 213km/h, operation at temperatures -40°C/52°C, lifting up to 968kg on the external cargo hook, making slope landings up to 10° in any direction, operation with emergency floats and for installation of a movable landing light and additional wire strike protection on the fuselage. The MD 600N also completed HIRF trials at NAS Patuxent River, Maryland. Yaw-stability augmentation system (Y-SAS) was under development during 2000, aimed at reducing pilot workload during extended flights and in turbulent conditions.
Total of 68 registered by May 2003. Launch customer AirStar Helicopter of Arizona (two, of which first delivered 6 June 1997); Saab Helikopter AB of Sweden and Rotair Limited of Hong Kong ordered one each in June 1995; other customers include Guangdong General Aviation Company (GGAC) of the People's Republic of China, which took delivery of one MD 600N in November 2000, during Airshow China 2000 in Zhuhai, Los Angeles County Sheriff’s Department Aero Bureau (three), Orange County, California, Sheriff’s Department, Indianapolis, Indiana. Police Department (one), Presta Services of France (one), Turkish National Police, which ordered 10 in December 2000 for delivery during 2002 (subsequently postponed to 2003), UND (University of North Dakota) Aerospace (one), West Virginia State Police (one) and the US Border Patrol (45, of which 11 delivered by end of 1998. when procurement halted pending evaluation of UAVs for border patrol role). Deliveries totalled 15 in 1997, 21 in 1998, six in 1999, seven in 2000, two in 2001 and two in 2002.
Costs: US$1.315 million (2002).
February 19, 1999 : Boeing sold MD commercial line to RDM The dutch company bought the ex Mc Donnell Douglas models MD 500E and MD 530F single-engine helicopters with conventional tail rotors, the MD 520N and MD 600N single-engine NOTAR helicopters and the MD Explorer series of twin-engine, eight-place helicopters.