Mitsubishi Diamond 1A

In 1969, Mitsubishi Heavy Industries initiated an extensive program of market research to determine the demand for a small business jet.

As a result of this study, Mitsubishi embarked in the mid-1970s on the development of the MU-300 Diamond, a light twin-engine, turbofan-powered corporate transport designed to compete directly with the Cessna Citation and Learjet 25. The Diamond I made its first flight in August 1978.

A lengthy and difficult certification effort ensued, resulting finally in approval under FAA Part 25 in November 1981. Weight gains suffered during the certification process hampered the Diamond’s high/hot performance.

The Diamond 1A featured the -4D variant of the venerable Pratt and Whitney JT15D engine, flat-rated to 25 degrees C. This allowed the aircraft to benefit from the full take-off thrust of 2,500lbs. over a wider range of conditions.

The Diamond II replaced the 1A in 1985 after a production run of 70 aircraft. The Diamond II used the JT15D-5 turbofan, producing 2,900lbs. of thrust up to 27 degrees C.

Only eight Diamond IIs were built before the manufacturing rights were transferred to Raytheon/Beech, who continue to produce the aircraft in its most current variation as the Beechjet 400A.

The Diamond 1A is powered by two Pratt and Whitney of Canada JT15D-4D turbofan engines rated at 2,500lbs of thrust each.

The inspection interval on the engines is 3,500 hours.

The aircraft has a maximum operating altitude of 41,000 feet, a normal cruise speed of 406 knots (467 MPH), and a 1,112 nautical mile (1,279 miles) seats-full range.

The Mitsubishi Diamond 1A has a 4,923 feet balanced field length and 3,500 feet landing distance.

The Diamond 1A can accommodate seven to eight passengers in a cabin normally arranged with a four-place club and a side divan across from the entry door.

A full-width aft lavatory has some baggage space and there is an additional rear baggage compartment accessible from the exterior.

Cabin dimensions are 4.8ft. in height, 4.9ft. in width, and 15.6ft. in length.

A typical avionics installation includes dual Collins VHF 20A comms, dual VIR 30A navs, DME, ADF, dual TDR 90 transponders, Sperry APZ 500 flight director, SPZ 900 autopilot, and Primus 300SL color weather radar.

The cost to charter this jet starts at around $2,600 an hour. Hourly charter rates do not include all taxes, fuel, and other fees.

Charter costs will vary based on year of make/model, schedule, routing, passenger & baggage totals, and other factors.