Design work on the YS-11 began in 1957 when the Japanese Ministry of International Trade and Industry (MJTI) urged six of the country’s leading aviation companies to join forces in the development of what was to become Japan’s first postwar airliner. The ensuing joint design bureau became known as TADA (Transport Aircraft Development Association or Yusoki Sekkei Kekyu Kyokai). What finally came off the drawing boards was a conventional design, tailored for the Japanese domestic market. In 1959 TADA was replaced by NAMC (Nihon Aeroplane Manufacturing Company) to provide manufacturing and marketing capability. Among the participating companies, construction responsibilities were divided as follows: Fuji – tail unit; Japan Aircraft – control surfaces; Kawasaki – wings; Shin Meiwa- aft fuselage; Showa Aircraft – composite structures; and Mitsubishi – forward fuselage and final assembly.

NAMC YS-11 Article

Two prototypes were built by NAMC, each powered by two 3,060 h.p. Rolls-Royce Dart RDa.10/1MkP542 engines, plus two further airframes for static testing. Fifty-four YS-11s were to be built between 1963 and 1966, according to plans, for All-Nippon Airways (25), Japan Air Lines (about 10), the Japanese Defence Agency (10), the Maritime Safety Agency (2 for ASR) and the Meteorological Agency (four for weather observation).

The first flight came on August 30, 1962, when the YS-11 first took to the skies. Japan Domestic Airlines placed the type into service on April 1, 1965. A higher gross weight version, the YS-11A, became available in 1967. Not surprisingly, Japanese airlines were the largest customers, although Piedmont Airlines took delivery of 21 aircraft. Other customers included Hawaiian Airlines, Cruzeiro do Sul, VASP, and Olympic Airways.
Throughout its production life, the YS-11 was dependent on state subsidies. In 1971 the Japanese government announced that it would no longer provide financial backing and production ended two years later, with a total of 182 aircraft completed. Although from an economic point of view the YS-11 was a Y38 billion disaster for Japanese taxpayers, the airplane itself proved to be a solid and reliable design. Over the years, many YS-11s were passed on to smaller operators all over the world. Among these were a number of US-based com¬panies, such as Mid Pacific Air, Provincetown-Boston Airline, Reeve Aleutian Airways, Simmons Airlines, Pinehurst Airlines, and Airborne Express.

112 of the YS 11 were in service in 1981, the largest operators being TDA with 42 and ANA with 34. The fleet has totalled more than three million hours.

Engines: two 3,060 h.p. Rolls-Royce Dart RDa.10/1MkP542
Span: 105 ft
Length: 86 ft 3 in
Height: 30 ft
Gross weight: 50,265 lb
Empty weight (equipped): 31,970 lb
Max cruising speed at 20,000ft: 296 mph
Econ cruising speed at 20,000ft: 288 mph
Max rate of climb at SL: l,520 ft/min
Service ceiling: 27,500 ft
TO field length (SR422B): 2,900 ft;
Landing field length (SK422B): 3,790 ft
Range max fuel/ 5,4001b load, res 230-mile & 45min: 1,485 miles
Range with max payload, same res: 380 miles

YS-11A-500
Engines: 2 x RR Dart
Length: 26.3m (86.3ft)
Wing span: 32m (105ft)
MTOW: 25,000kg (55,115kg)
Max payload: 5,900kg (13,000lb)
Economical cruise: 245kt
ROC: 800fpm at l40kt
Takeoff dist: 1,200m (3,940ft)
Landing dist: 1,000m (3,280ft)
Range (max fuel): 1,735nm
Range (max load): 600nm

YS-11A-600
Engines: 2 x RR Dart

In 1959, MHI started on a utility/ executive aircraft aimed at the emerging business aviation market. It was announced in April 1962 that Mitsubishi were to build one flying prototype and a structure test airframe of a shoulder-wing twin-turboprop utility aircraft under the XMU-2 designation. A mock-up had been built and the aircraft is described as being similar in appearance to the Aero Commander, but smaller, with a circular-section fuselage. The engines were to be French or Canadian turboprops of 500 hp each.

Mitsubishi MU-2 Article

On 14 September 1963 the first of four prototypes was flown, a cantilever high-wing monoplane with a pressurised fuselage, retractable tricycle landing gear and two wing-mounted turboprop engines. The first MU 2 prototype flew pow¬ered by French Turbomeca Astazou en¬gines. The fourth airplane to be tested was fitted with an early version of the Garrett AiResearch TPE 331, and all subsequent MU 2s have been powered by TPE 331 turboprops. By 1965, the short body MU 2B was certified by the FAA for use in the U.S. and sales to American firms began. To achieve roll control when the wing required full span flaps, Mitsubishi developed a small spoiler that resides at about the two thirds chord position and extends along most of the wing’s span.

Since 1965, MHI has improved the MU 2 as the technology of general avia¬tion aircraft advanced, but with the ex¬ception of powerplants and systems, very few changes in the airframe were neces¬sary. As more power was added, a speed increase of 15 percent and a gross weight increase of 30 percent was achieved. The first significant changes to the MU 2 ap¬peared in 1968 when the aircraft was fitted with larger tip tanks and powered by 705 eshp TPE 331s.

Initial production versions were the MU-2A with Turbomeca Astazou turboprops, MU-2B with Garrett TPE331 turboprops and a similar MU-2D, an unpressurised multi-role MU-2C for the Japanese Ground Self-Defence Force, a search-and-rescue MU-2E, and the MU-2F with uprated TPE331 engines.

Models B and D were powered by 605 shp and seated 7-9 passengers. The Model F represented a boost in power to 705 shp.

Certification of the MU-2B-26A is FAA A10SW, and the MU-2B-30 JCAB 25.

The first stretched (by 1.88 m) MU 2 was the G model, which was based on the MU 2F and introduced in 1969. The Model G featured increased seating capacity for up to 11 people, and the powerplant of the MU-2F.

In 1971, the eshp of the AiResearch turbines was increased to 724 for use on the long bodied MU 2J and the short bodied MU 2K, which were introduced in mid 1972. Both utilizing 724-shp turboprops and offering seating arrangements that corresponded to Models F and G, respectively.

Subsequent versions have included the MU-2J with more powerful engines, and MU-2K combining MU-2F fuselage and MU-2J powerplant.

The MU 2L and M models (variants of the MU-2J and MU-2K respectively), with their increased gross weights and added soundproofing, were an¬nounced at NBAA in September, 1974. Fitted with full span, high lift flaps and two Garrett AiRe¬search TPE 331 6 251M engines, rated at 776 equivalent shaft horsepower on the L model and at 724 eshp on the M model. Thus, both Mitsubishis have power loadings of 8.1 pounds of aircraft per horsepower for the MU 2L ¬and 7.9 lbs/hp for the MU 2M. The L and M model use AiResearch cabin pressurization systems with Hamil¬ton Standard air conditioning utilizing bleed air from the engines. The MU 2L, nine feet longer inside than the MU-2M, providing ac-commodations for a pilot and from seven to ten passengers. The MU 2L uses 178 square feet of wing area and a NACA 64A415 airfoil to produce a high speed wing that carries a load of 65 pounds per square foot.

The MU-2L and MU-2M were discontinued in 1976 and replaced by the MU-2N and MU-2P with Garrett TPE331-5-252M engines. The 90 inch, three blade propellers that were standard on MU 2Ls and Ms are replaced on the latest models by 98 inch, four¬blade props that turn at 1,591 rpm on take off, only 80 percent of the revolu¬tions previously used. Because of the slower turning propellers, the propeller tip speeds are reduced about 100 feet per second in spite of the increased prop diameter needed to produce the same thrust horsepower available on older MU 2s. The result is a dramatic 25 per¬cent reduction in perceived noise levels within the cabin and no loss in per¬formance.

The new aircraft are designated the MU 2N and the MU 2P (the latter model has the shorter fuselage). In addition to larger, slower turning propellers, both models are equipped with the Woodward fuel control units; a move which will mark a return to the fuel con¬trol units utilized by Mitsubishi in their early MU 2 models. Purchasers of L or M model Mitsubishis have the option to upgrade their new aircraft to the stan-dards of the MU 2N or MU 2P, respective¬ly, should they wish to have the slow turning engines with the Woodward fuel controllers.

The MU 21P 98 inch four blade propellers have been slowed 20 percent, to 1,591 rpm for takeoff and 1,561 during cruise. According to the factory, that reduces the interior noise level by 25 percent. A vertical fin now sprouts from the top of each tip tank, to help improve low-¬speed roll stability, and there’s a new taxi light in the nose of each tank. A new windshield can be seen in the cockpit; the new glass creates less distortion.
Spoilers replace the ailerons to good advantage; they remain equally effective at all airspeeds, eliminate adverse aileron yaw and, most significantly, permit space for almost full span double slotted Fowler flaps. When fully ex¬tended, the flaps increase wing area by 24 percent and reduce stalling speed by 24 knots. Taking off at Vmc (93 knots) allows the airplane to clear a 50 foot obstacle in 1,800 feet at gross on a standard day. In fact, the airplane’s single engine rate of climb is 760¬ fpm, at a typical weight of 9,250 pounds. The MU 2P is a short coupled machine, and this shows up during takeoff and landing. Bluntly stated, the MU 2P is lacking in pitch¬ control power, and some piloting effort is re¬quired to compensate for that shortcoming. The problem is apparently limited to the short fuselage version; the longer body MU¬2s, including the new four blade MU 2N, do not display any pitch difficulties. When leav¬ing or entering ground effect during takeoff or landing, the low mounted tailplane is af¬fected more than the high wings because of the particular relationship between them, and this produces a forward pitching force. The MU 2P, with its short fuselage and narrow center of gravity, demonstrates the effects of this nose down load more vividly than do most airplanes.

An ar¬rangement was struck with Mooney Aircraft for assembly and marketing of the MU 2, and that lasted until it was dissolved in 1970 after Mooney had been purchased by Butler Aviation. But as early as 1967, Mitsubishi Aircraft International, Inc. had been formed, and by 1970, MAI was in a position to take over both the assembly of MU 2s in San Angelo and marketing of the product. Mitsubishi Aircraft Interna-tional, Inc., a U.S. corporation based in San Angelo, Texas was responsible for assembling MU 2s and marketing them in the US and throughout the world.

The MU-2S is the Japan Air Self-Defence Force patrol aircraft, which resembles the civilian aircraft but has a shorter fuselage and bulbous radar nose.

The MU-2N and MU-2P evolved into the Solitaire (standard fuselage) and Marquise (stretched fuselage), respectively. Both airplanes have 1,000 ¬horsepower engines, wet wing fuel tanks that hold an additional 40 gallons and are certificated to 31,000 feet. The MU 2 designation will be dropped. The Solitaire succeeded the MU 2P, and the Marquise the larger, slower MU 2N.

The Solitaire is powered by two Garrett TPE331-10-501M turboprops producing 727 shp at maximum continuous power or 689 shp at recommended cruise power of 96% RPM. Each engine turns a Hartzell 98-inch four-blade prop and provides a 475-fpm single-engine rate of climb when loaded to full gross. With a cabin pressurization differential of 6.0 psi, a sea-level cabin can be maintained up to 14,000. The Marquise, which is 6 feet 2 inches longer, is powered by two turboprops, each producing 778- shp for takeoff or maximum continuous operation and 738 shp at recommended cruise power. Single-engine rate-of-climb is 410 fpm at full gross, and cabin pressurization differential is the same as the Solitaire. The long-fuselage Marquise accommodates a crew of two plus seven to nine passengers; and the Solitaire, seating a crew of two plus six or seven passengers.

Sales of the Mitsubishi MU 2 passed the 700 mark in July 1981 when the total reached 702. Since the twin turboprop business transport was introduced in 1966, 518 were sold in the USA, 20 in Canada, 58 in Latin America, 36 in Europe, nine in Africa, eight in Australia, one each in the Middle East and Asia and 51 in Japan. The last 100 aircraft were sold since September 1979.

When production ended at the end of 1983, 831 MU-2s of all versions had been built, including 73 military versions.

MU 2 prototype
Engines: 2 x Astazou II turbo-prop, 415kW
Wingspan: 10.3 m / 33 ft 10 in
Length: 10.1 m / 33 ft 2 in
Height: 4.0 m / 13 ft 1 in
Wing area: 16.6 sq.m / 178.68 sq ft
Max take-off weight: 3600 kg / 7937 lb
Empty weight: 2072 kg / 4568 lb
Max. speed: 525 km/h / 326 mph
Cruise speed: 523 km/h / 325 mph
Ceiling: 11000 m / 36100 ft
Range w/max.fuel: 2830 km / 1759 miles
Crew: 1-2
Passengers: 5-13

MU-2B-26A
Engines: 2 x Garrett TPE-331-252M, 605 shp.
Seats: 7/9.

MU-2B-60 Marquise
Engines: 2 x Garrett TPE-331-10-501M, 715 shp.
Props: Hartzell 4-blade, 98-in.
Seats: 9/11.
Length: 39.4 ft.
Height: 13.7 ft.
Wingspan: 39.2 ft.
Wing area: 178 sq.ft.
Wing aspect ratio: 7.7.
Maximum ramp weight: 11,625 lbs.
Maximum takeoff weight: 11,575 lbs.
Standard empty weight: 7650 lbs.
Maximum useful load: 3975 lbs.
Zero-fuel weight: 9950 lbs.
Maximum landing weight: 11,025 lbs.
Wing loading: 65 lbs/sq.ft.
Power loading: 8.1 lbs/hp.
Maximum usable fuel: 2700 lbs.
Best rate of climb: 2100 fpm
Service ceiling: 29,400 ft.
Max pressurisation differential: 6 psi.
8000 ft cabin alt @: 27,300 ft.
Maximum single-engine rate of climb: 410 fpm @ 152 kts.
Single-engine climb gradient: 158 ft/nm.
Single-engine ceiling: 14,800 ft.
Maximum speed: 309 kts.
Normal cruise @ 20,000ft: 295 kts.
Fuel flow @ normal cruise: 592 pph.
Endurance at normal cruise: 4.1 hrs:
Stalling speed clean: 100 kts.
Stalling speed gear/flaps down: 81 kts.
Turbulent-air penetration speed: 191 kts.
Takeoff distance (50′) 2,170 ft
Landing distance (50′) 2,200 ft

MU-2B-400 Solitaire
Engines: 2 x Garrett TPE-331-10-501M, 665 shp
Props: Hartzell 4-blade, 98-in
Seats: 7/9
Length: 33.3 ft
Height: 12.9 ft
Wingspan: 39.2 ft
Wing area: 178 sq.ft
Wing aspect ratio: 7.7
Maximum ramp weight: 10,520 lbs
Maximum takeoff weight: 10,470 lbs
Standard empty weight: 7010 lbs
Maximum useful load: 3510 lbs
Zero-fuel weight: 9700 lbs
Maximum landing weight: 9950 lbs
Wing loading: 59 lbs/sq.ft
Power loading: 7.8 lbs/hp
Maximum usable fuel: 2700 lbs
Best rate of climb: 2250 fpm
Service ceiling: 31,000 ft
Max pressurisation differential: 6 psi.
8000 ft cabin alt @: 27,300 ft
Maximum single-engine rate of climb: 475 fpm @ 150 kts
Single-engine climb gradient: 190 ft/nm
Single-engine ceiling: 16,900 ft
Maximum speed: 321 kts
Normal cruise @ 25,000ft: 309 kts
Fuel flow @ normal cruise: 526 pph
Endurance at normal cruise: 4.6 hrs
Stalling speed clean: 104 kts
Stalling speed gear/flaps down: 78 kts
Turbulent-air penetration speed: 182 kts

MU-2J

MU 2L
Engines: 2 x AiResearch TPE 331¬6 251M, 776 eshp
Max cruise pwr: 767 eshp
Prop: Hartzell 90in Constant speed, full feather with reverse pitch
Span: 39 ft. 2 in
Overall length: 39 ft. 5 in
Overall height: 13 ft. 8 in
Wing area: 178 sq. ft
Cabin length: 19 ft. 8 in
Cabin width: 4 ft. 11 in
Cabin height: 4 ft. 3.2 in
Baggage compartment: 44 cu. Ft
Seats: 8 11
Empty weight: 6,380 lbs
Standard equipped weight: 7,570 lbs
Max takeoff weight: 11,575 lbs
Max ramp weight: 11,625 lbs
Useful load (with std equip): 4,055 lbs
Payload with full fuel: 1,603 lbs
Usable fuel capacity: 366 US gal
Max cruise: 340 mph
Rate of climb at sea (10,350 lbs): 2,630 fpm
ROC SE: 675 fpm
Service ceiling (10,350 lbs): 29,600 ft
Service ceiling (10,350 lbs) SE: 15,450 ft
Stall speed: 88-115 mph
Max range 30 min res: 1450 miles
Takeoff distance over 50 ft. at 11,575 lbs: 2170 ft
Ldg dist from 50 ft. at 9,473 lbs: 1880 ft
Pressurization: 6.0 psi
Cabin alt @ 24,000 ft: 6200 ft

MU 2M
Engines: 2 x AiResearch TPE 331¬6 251M, 724 eshp
Max cruise pwr: 715 eshp
Prop: Hartzell 90in Constant speed, full feather with reverse pitch
Span: 39 ft. 2 in
Overall length: 33 ft. 3 in
Overall height: 12 ft. 11 in
Wing area: 178 sq. ft
Cabin length: 11 ft
Cabin width: 4 ft. 11 in
Cabin height: 4 ft. 3.2 in
Baggage compartment: 43 cu. Ft
Seats: 7 9
Empty weight: 5,920 lbs
Standard equipped weight: 6,864 lbs
Max takeoff weight: 10,470 lbs
Max ramp weight: 10,520 lbs
Useful load (with std equip): 3,656 lbs
Payload with full fuel: 1,204 lbs
Usable fuel capacity: 366 US gal
Max cruise: 365 mph
Rate of climb at sea (9,250 lbs): 2,840 fpm
ROC SE: 760 fpm
Service ceiling (9,250 lbs): 32,200 ft
Service ceiling (9,250 lbs) SE: 18,000 ft
Stall speed: 84-112 mph
Max range 30 min res: 1680 miles
Takeoff distance over 50 ft. at 10,470 lbs: 1800 ft
Ldg dist from 50 ft. at 8338 lbs: 1600 ft
Pressurization: 6.0 psi. Cabin alt @ 24,000 ft: 6200 ft
Wing loading: 58.8 lb/sq.ft

MU-2N
Engines: 2 x Garrett TPE 331-6-251M, 715 hp
Seats: 11
Wing loading: 65 lb/sq.ft
Pwr loading: 8.1 lb/hp
Gross wt: 11,625 lb
Empty wt: 7570 lb
Equipped useful load: 4040 lb
Payload max fuel: 1601 lb
Range max fuel/cruise: 772 nm/2.6 hr
Range max fuel / range: 1112 nm/ 4.5 hr
Service ceiling: 25,000 ft
Max cruise: 291 kt
Max range cruise: 250 kt
Vmc: 99 kt
Stall: 79-105 kt
1.3 Vso: 103 kt
ROC: 2200 fpm
SE ROC: 420 fpm @ 152 kt
SE Service ceiling: 12,000 ft
Min field length: 2200 ft
Cabin press: 6 psi.
Fuel cap: 2439 lb

MU 2P
Engines: 2 x AiResearch TPE 331 5 252M, 665 shp
Props: Hartzell four blade, full feathering, reversible
Length: 33 ft 3 in
Height: 12 ft 11 in
Wingspan: 39 ft. 2 in
Wing area: 178 sq. ft
Wing loading: 58.8 lb/sq.ft
Power loading: 7.9 lb/hp
Seats: 7
Empty wt: 7,050 lbs
Useful load: 3,420 lb
Payload with full fuel: 1,236 lbs
MTOW: 10,470 lb
Usable fuel cap: 364 USG/2,184 lbs
Max landing wt: 9,955 lb
Max ROC: 2,450 fpm
SE ROC: 475 fpm
SE climb gradient (150 kt Vyse): 190 ft/nm
Service ceiling: 32,200 ft
Certificated ceiling: 28,000 ft
SE service ceiling: 16,800 ft
Max cruise at 16,000 ft: 306 kts
Econ cruise at 24,000 ft: 272 kt
Duration at max cruise: 3.9 hrs
Duration at econ cruise: 5.9 hrs
Stalling speed, clean: 103 kts
Stalling speed, full flaps: 78 kts
Pressurization differential: 6 psi
10.000 ft. cabin at: 31,200 ft.