Register Review

The New Allocations this issue contains one completely new type and two new sub-types, with the most interesting being Rotor Force Australia’s McDonnell Douglas MD-900 Explorer EPX.

The Explorer made its maiden flight in December 1992 and was the first production helicopter to incorporate the NOTAR system into its initial design. The earlier MD520 was basically a Hughes 500 converted to NOTAR from the bulkhead back. The NOTAR system, an acronym standing for NO TAil Rotor, was developed by Hughes Helicopters before it was taken over by McDonnell Douglas in 1984 and then merged with Boeing in 1997. Interestingly, the patent for the concept is still held by Boeing.