MD Helicopters MD 600

MD 600N
	A MD 600N with NOTAR
Role	Light utility helicopter
National origin	United States
Manufacturer	McDonnell Douglas Helicopter Systems; MD Helicopters
First flight	22 November 1994
Status	In service
Primary user	United States Border Patrol
Produced	1995–present
Developed from	MD Helicopters MD 500

The MD Helicopters MD 600N is a light utility civilian helicopter designed in the United States. It is a stretched eight-seat development of the five-seat MD 520N helicopter.

Design and development[]

McDonnell Douglas Helicopter Systems (MD Helicopters since 1999) first announced it was developing a stretched MD 520N in late 1994, at that time designated the MD 630N.^[1] The prototype, a modified MD 530F, had made its first flight on November 22, 1994. McDonnell Douglas gave the go-ahead for the production aircraft, redesignated the MD 600N, in March 1995.

McDonnell Douglas stretched the MD 520N fuselage by inserting a plug aft of the cockpit/cabin bulkhead and stretching the NOTAR tail boom. The larger fuselage allows for an extra (middle) row of seats. Other differences compared with the MD 520N include a new six blade main rotor (the MD 520N has a five blade unit) and an uprated Allison (now Rolls-Royce) Model 250 turboshaft.

The prototype was modified to MD 600N standard with a production standard engine and tail boom and flew in November 1995, followed the next month by the first MD 600N production prototype.^[1] Certification was awarded on May 15, 1997, and deliveries began that June.

Following the 1997 Boeing/McDonnell Douglas' merger, Boeing sold the former MD civil helicopter lines to Netherlands-based RDM Holdings in early 1999.^[1]

On March 8, 2017, MD Helicopters unveiled a concept variant known as the MD 6XX.^[2] Unlike the MD 600, the MD 6XX utilizes a traditional tail rotor and shares its T-tail design with the smaller MD 500/530F. It is currently^[when?] in development, with certification originally expected in 2020.^[3] However, certification has been delayed indefinitely.^[4]