MD 600N is a
light utility civilian helicopter. It is a stretched eight-seat development of
the five-seat MD520N helicopter. 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).