Mitsubishi MU-2

The Mitsubishi MU-2 is one of postwar Japan's most successful aircraft. It is a high-wing, twin-engine turboprop, and has a pressurized cabin.

Design and development

MU-2 landing

Work on the MU-2, Mitsubishi's first postwar aircraft design, began in 1956. Designed as a light twin turboprop transport suitable for a variety of civil and military roles, the MU-2 first flew on 14 September 1963. This first MU-2, and the three MU-2As built, were powered by the Turbomeca Astazou turboprop.^[2]

Civil MU-2s powered by Garrett engines were certified as variants of the MU-2B, using the MU-2B type followed by a number. For marketing purposes, each variant was given a suffix letter; the MU-2B-10, for example, was sold as the MU-2D, while the MU-2B-36A was marketed as the MU-2N.^[3]

Production

In 1963 Mitsubishi granted Mooney Aircraft rights in North America to assemble, sell and support the Mu-2. In 1965, Mooney established a facility to assemble MU-2s at a new factory in San Angelo, Texas, major components were shipped from Japan and the San Angelo factory installed engines, avionics and interiors, they would then paint, flight test and deliver to customers. By 1969 Mooney was in financial difficulty and the San Angelo facility was taken over by Mitsubishi. Production in the United States ended in 1986 with over 750 MU-2 aircraft sold.^[4] The last Japanese-built aircraft was completed in January 1987.

The subsequent production aircraft, designated MU-2B, were delivered with the Garrett TPE331 engines that remained standard on all later models. 34 MU-2Bs were built, followed by 18 examples of the similar MU-2D.^[2] The Japanese armed forces purchased four unpressurized MU-2Cs and 16 search and rescue variants designated MU-2E. Featuring slightly more powerful upgraded TPE331 engines, 95 examples of the MU-2F were sold.

A stretched-fuselage Mitsubishi MU-2 Marquise taxiing at the Toronto City Centre Airport. This MU-2 is operated in a medevac configuration by Thunder Airlines of Thunder Bay, Canada

The fuselage was stretched beginning with the MU-2G; these aircraft are covered in later paragraphs. The MU-2M (only 28 built) is regarded as the toughest and most desired of all short body MU-2s, especially with a -10 engine conversion. It had a short fuselage and the same engines as the stretched MU-2J; it was followed by the even more powerful MU-2K and later the MU-2P, which had newer four-blade propellers. The final short-fuselage MU-2s produced were known as the Solitaire and were fitted with 496 kW (665 shp) Garret TPE331-10-501M engines.^[2]

The first significant change to the airframe came with the stretched MU-2G, first flying 10 January 1969, which featured a 1.91 m (6 ft 3 in) longer fuselage than earlier models; 46 were built before being succeeded by the more powerful MU-2J (108 constructed). The MU-2L (29 built) was a higher-gross-weight variant, followed by the MU-2N (39 built) with uprated engines and four-blade propellers. The final stretched-fuselage MU-2 was named the Marquise, and like the Solitaire used 533 kW (715 shp) TPE331 engines.^[2]

As of 2005, 397 MU-2 aircraft are registered in the United States.

Operational history

Military service

A military version for JGSDF.

The Japanese Self-Defense Forces are the only military operators to have flown the MU-2 in front-line service. The four C-model aircraft built, in addition to 16 MU-2Ks, entered service with the Japan Ground Self-Defense Force with the designation LR-1; they were used as liaison and photo reconnaissance aircraft. 29 MU-2Es were purchased by the Japan Air Self-Defense Force as search-and-rescue aircraft and designated MU-2S. Additional equipment consisted of a "thimble" nose radome, increased fuel capacity, bulged observation windows, and a sliding door for dropping rafts.^[3]

MU-2s are currently flown under government contract at Tyndall Air Force Base, Florida, where they provide U.S. Air Force undergraduate Air Battle Manager students with their initial experience controlling live aircraft. Students must control eight MU-2 missions before they can progress to controlling high performance aircraft such as F-15s or F-22s.^[5]

The Royal New Zealand Air Force announced 29 July 2009 that it will take delivery of four non-flying Mitsubishi MU-2F fixed-wing training aircraft during third quarter 2009 for use as training aids. The aircraft will be located at the RNZAF's Ground Training Wing (GTW) at Woodbourne near Blenheim. ^[6]

Flight Around the World

On August 25th, 2013 Mike Laver, owner and pilot of N50ET (a -10 engine converted 1974 K model equipped with 5 blade MT composite propellers which had just received an STC under Air 1st of Aiken SC) along with AOPA Pilot technical editor Mike Collins embarked on an around the world journey in the MU-2B-25.^[7] The voyage commenced at Aiken Municipal Airport and will sojourn in Nagoya, Japan on September 14th, 2013; the 50th anniversary of the MU-2.^[8][9]

Safety Concerns

Concerns have been raised about safety; there have been 330 fatalities from MU-2 crashes.^[10] As of October 2005, the Federal Aviation Administration (FAA) has begun a safety evaluation of the aircraft and decided that the aircraft has met its certification requirements - it is safe when operated by properly trained pilots who operate properly maintained aircraft. The FAA is in the process of mandating training specific to the MU-2 as it has in the past for other aircraft. When such mandated training was required outside of the U.S. the MU-2 accident record was vastly improved.

Because the MU-2 offers very high performance at a relatively low cost, some of its operators lack sufficient training and experience for such an advanced aircraft.

A design feature of the MU-2 is its high cruise speed while having a low landing speed. This is accomplished by using full-span, double-slotted flaps on the trailing edge of the wing. These flaps give the MU-2 a wing area comparable to a Beech King Air in landing configuration while having a wing area comparable to a light jet while in cruise mode. The full-span flaps meant that over-wing spoilers were employed instead of conventional ailerons. These spoilers are highly effective, even when the MU-2 wing is stalled. Some fatal accidents have occurred because normal engine-out procedures for light twin aircraft are not effective when flying the MU-2. The commonly taught procedure of reducing flap following an engine failure on take off leads to a critical reduction in lift in the MU-2 due to the highly effective double-slotted flaps. When pilots were taught to retain take-off flap and to reduce climb rate in the event of an engine failure, MU-2 accident rates reduced to almost nil.

From an FAA press release:

The FAA began an aggressive safety evaluation in July 2005. The evaluation is performing a detailed review of accidents, incidents, airworthiness directives, service difficulty reports, safety recommendations and safety reports. It also is examining pilot training requirements, the history of the aircraft's commercial operators and possible engine problems. The goal is to identify the root causes of MU-2 accidents and incidents and determine what, if any, additional safety actions are needed.

In early 2008, the FAA issued a Special Federal Air Regulation (SFAR) directed at MU-2B operations. Pilots flying this aircraft after that date (current MU-2 pilots would have a year to come into compliance) were required to receive type-specific initial training, as well as recurrent training. It also required that a fully functional autopilot be available for single-pilot operations, and that FAA-approved checklists and operating manuals be on board at all times. Also unusual for this SFAR, pilot experience in other aircraft types cannot be used to comply with MU-2 operational requirements - for instance, the requirement to perform landings within the preceding 90 calendar days before carrying passengers is altered by this SFAR to require those landings be made in the MU-2.^[11]

As of Nov. 21st, 2013 there have been only 2 fatal accidents involving the MU-2 since the FAA SFAR was implemented.

Variants

Short fuselage

XMU-2

Astazou-powered prototype, one built

MU-2A

Astazou-powered development aircraft, three built.

MU-2B

Production variant with Garrett TPE-331 engines, 34 built.

MU-2C (MU-2B-10)

Unpressurised variant for the Japanese Ground Self Defense Force, four built.

MU-2D (MU-2B-10)

Improved MU-2B, higher operating altitude and bladder fuel tanks rather than wet-wings, 18 built.

MU-2DP (MU-2B-15)

MU-2D with 90-gallon tip tanks and upgraded engines, three built.

MU-2E

Unpressuised variant for the Japanese military designated MU-2S

MU-2F (MU-2B-10)

Variant with improved engines and 90-gallon tip tanks as MU-2DP but certfied at a higher gross weight and additional fuel tanks, 95 built.

MU-2K (MU-2B-25)

Short fuselage variant of the MU-2J, 83 built.

MU-2M (MU-2B-26)

Revised variant of the MU-2K with increased weight, and increased cabin pressure, 27 built.

MU-2P (MU-2B-26A)

Improved variant with four-bladed propellers and improvements as MU-2N, 31 built.

Solitaire (MU-2B-40)

Variant with improved engines and increased fuel capacity, 57 built between 1979 and 1985.

Long fuselage

MU-2G (MU-2B-30)

Stretched variant with a 1.91m increase in length, larger cabin and change to landing gear configuration, first flown in January 1969, 46 built.

MU-2J (MU-2B-35)

Variant with improved engines, eleven inch increase in cabin length and increased gross weight, 108 built.

MU-2L (MU-2B-36)

Revised variant of the MU-2L with increased weight, and increased cabin pressure.

MU-2N (MU-2B-36A)

Improved variant with four-bladed propellers and other improvements including an extra cabin window, 36 built.

Marquise (MU-2B-60)

Variant with improved engines, 139 built.

Military

LR-1

Japanese military designation for MU-2C and MU-2Ks operated by the JGSDF, 20 delivered.

MU-2S

Japanese military designation for a MU-2E search and rescue variant for the air force, 29 delivered.

Aircraft on display

• MU-2A JA8620 the first production aircraft is on display at the Niigata Science Museum, Niigata.
• MU-2B-25 JA8628 the fifth production aircraft is on display at the Museum of Aeronautical Sciences, Tokyo-Narita.
• An MU 2 is on display at Darwins Air Museuam based on the Darwin Airport Australia.

This aircraft had been used on coastal survilence duties under controversial circumstances over the appointment of the contracting company. The plane was sold to a parts recycler who removed hi value parts such as the engines and the airframe was handed to the museum for static display.

• MU-2 Marquise 1575 is the last assembled MU-2 from the San Angelo, TX production facility. It is currently on display at the Spirit of Flight Center air museum in Erie, CO.
• An MU-2 is on display at Sparks Aviation on the north side of Tulsa International Airport, Tulsa, Oklahoma.

Incidents and accidents

• On March 24, 1983, an MU-2B-60, registration N72B, was en route from Jacksonville, FL, to Atlanta, GA, level at 18,000 feet. The aircraft was hauling cancelled checks and had just been handed off from JAX Center to ATL center when it disappeared from radar at approximately 2:30am. The wreckage was spread over a two-mile area. According to the NTSB report, the right wing failed upward and the left wing failed downward.^[12]

• A spate of accidents involving MU-2s occurred in Australia between 1988 and 1994, all caused by icing on the airframe which caused the airspeed to decrease to the point where each aircraft stalled and entered a spin.

• On 16 December 1988, an MU-2B-60 crashed near Leonora, Western Australia. The pilot and nine passengers were killed.^[13]

• On 26 January 1990, an MU-2B-60 crashed near Meekatharra, Western Australia. The pilot and one passenger were killed. The Leonora investigation was extended to include this crash given the same aircraft type crashed in similar circumstances.^[13]

• On 7 November 1990, a cargo MU-2B-30 crashed near Bathurst, New South Wales. The aircraft was damaged beyond repair.^[14]

• On 21 December 1994, two MU-2s crashed in separate but similar circumstances on approach to Melbourne Airport. One of the pilots was killed.^[15][16]

• On 19 April 1993, an MU-2 reported engine trouble while flying near Dubuque, Iowa and crashed into a farm silo about nine miles south of that city. All eight people aboard the aircraft were killed, including South Dakota Governor George S. Mickelson. The state-owned airplane was returning to South Dakota from a lobbying effort in Ohio. Coincidentally, the crash took place on the same day as the end of the Branch Davidian siege near Waco, Texas, which overshadowed the crash in national news coverage.^[17][18]

• On 18 January 2010, an MU-2-2B-60 crashed on approach to Lorain County Regional Airport, killing the two pilots and both passengers.^[19][20] The passengers were 89 year-old passenger Don Brown, inventor of a grid system for mounting drop ceilings, and his wife.^[21]

• On 10 November 2013, an MU-2-2B-25 crashed in a field in Owasso, OK, 1 is confirmed dead by the Oklahoma Highway Patrol. It is later announced that the deceased is Dr. Perry Inhofe, son of Senator Jim Inhofe, a Senior Republican Senator from Oklahoma ^[22]

Specifications (MU-2L)

Data from Jane's All The World's Aircraft 1976-77 ^[23]

General characteristics

• Crew: 1 or 2 pilots
• Capacity: 4-12 passengers
• Length: 12.01 m (39 ft 5 in)
• Wingspan: 11.94 m (39 ft 2 in)
• Height: 4.17 m (13 ft 8 in)
• Wing area: 16.55 m² (178 ft²)
• Empty weight: 3,433 kg (7,570 lb)
• Max. takeoff weight: 5,250 kg (11,575 lb)
• Powerplant: 2 × Garrett TPE331-6-251M turboprops, 579 kW (776 shp) each

Performance

• Maximum speed: 547 km/h (295 knots, 340 mph) at 4,575 m (15,000 ft) (max cruise)
• Cruise speed: 483 km/h (261 knots, 300 mph) at 7,620 m (28,000 ft) (econ cruise)
• Stall speed: 142 km/h (76.5 knots, 88 mph)
• Range: 2,334 km (1,259 nmi, 1,450 mi)
• Service ceiling: 9,020 m (29,600 ft)
• Rate of climb: 13.4 m/s (2,630 ft/min)
• Wing loading: 317 kg/m² (65.0 lb/ft²)
• Power/mass: 0.22 kW/kg (0.13 hp/lb)

See also

Aircraft of comparable role, configuration and era

• Rockwell Turbo Commander

References

• Taylor, John W.R. (1976). Jane's All The World's Aircraft 1976-77. London: Jane's Yearbooks. ISBN 0-354-00538-3. 

External links

Wikimedia Commons has media related to Mitsubishi MU-2.

• Mitsubishi Heavy Industries America MU-2 Official Website