NAMC YS-11

The NAMC YS-11 is a turboprop airliner built by a Japanese consortium, the Nihon Aircraft Manufacturing Corporation. The program was initiated by the Ministry of International Trade and Industry in 1954, the aircraft was rolled out in 1962, and production ceased in 1974. The YS-11 was produced at a loss, and was the only airliner wholly designed and manufactured in Japan until the development of the Mitsubishi Regional Jet.

Development and design


In the mid-to-late 1950s, the Japanese Ministry of International Trade and Industry identified a requirement for a short-haul airliner to replace Douglas DC-3s flying on Japan's domestic routes, and encouraged companies in Japan's aircraft industry to collaborate to develop and produce the new airliner. A joint venture between Mitsubishi Heavy Industries, Kawasaki Heavy Industries, Fuji Heavy Industries (now better known as the parent company of automobile manufacturer Subaru), Shin Meiwa, Showa Aircraft Industry Company and Japan Aircraft Industry Company was set up in 1957, being formalised as the Nihon Aeroplane Manufacturing Company (NAMC) in 1959. NAMC was a "paper company" that relied upon personnel and infrastructure provided by its constituent manufacturers.

NAMC designed a low-winged twin-turboprop monoplane seating 60 passengers. Jiro Horikoshi, the designer of the Mitsubishi A6M Zero fighter was involved in designing it. Another prominent engineer on the project was Teruo Tojo, the second son of Prime Minister Hideki Tojo, who later became chairman of Mitsubishi Motors. Although the aircraft was mainly designed and manufactured in Japan, the engines were built by Rolls-Royce, with the 2,275 kW (3,050 ehp) Rolls-Royce Dart RDa.10/1 being selected for the new aircraft. Due to the lack of domestic technology at the time, entire aircraft systems such as cabin pressurization were copied from foreign sources, using information gleaned from Japanese airlines, trading companies and diplomats.

Electronic equipment, avionics, mechanical and fuselage components were supplied either by Japanese companies or foreign suppliers during the YS-11's production lifetime. The twin-engined YS-11 delivered similar operational performance to the four-engined Vickers Viscount, and had 50% more capacity than the similarly configured Fokker F27 Friendship. MITI supervised the pricing of the aircraft in order to ensure that it was competitive with the Martin 4-0-4.

The first prototype made its maiden flight from Nagoya Airport on August 30, 1962, with the second prototype flying on December 28, 1962. It received its Japanese Type certificate on August 25, 1964, with American Federal Aviation Administration (FAA) certification following on September 9, 1965. All Nippon Airways used a YS-11 to carry the Olympic torch in the run-up to the 1964 Summer Olympics in Tokyo.

182 were produced in total, of which 82 were exported to 15 countries.

The last examples off the production line, mostly delivered to the Japan Air Self-Defense Force (i.e. YS-11A-402 EA/EB), were fitted with license-built General Electric T64-IHI-10J engines.

Operational history
The first production YS-11 flew on October 23, 1964 and was delivered on March 30, 1965, with initial airline operations by Toa Airways beginning in April 1965. At first, deliveries were mainly to Japanese airlines, and NAMC developed the YS-11A, with higher gross weight, to make the aircraft more attractive to the North American market, and in particular to meet the requirements of Piedmont Airlines, which ordered ten YS-11A-200s, with an option for an additional ten aircraft. Orders slowed after the needs of the Japanese commuter airlines for which it had been designed were met. This, together with losses growing to $600 million, resulted in production being stopped after completion of 182 aircraft, with the last YS-11 being delivered to the Japanese Maritime Self-Defence Force on May 11, 1973. The end of the program was precipitated by the 1971 Smithsonian Agreement, which led to an appreciation in the value of the Japanese yen.

112 YS-11s remained in service as of 1994. The YS-11 was slowly phased out by airlines in Japan due to new directives issued by the Ministry of Land, Infrastructure, Transport and Tourism requiring all commercial aircraft in Japan to be fitted with a Traffic Collision Avoidance System (TCAS). Aircraft without TCAS were forced to cease operations at the end of 2006. Since equipping a YS-11 with TCAS would have cost ¥100 million (about US$1 million), a refit was deemed economically unsound. Aircraft still in flying condition were sold to foreign companies. On September 30, 2006, Japan Air Commuter Flight 3806 marked the final flight for a YS-11 in Japan's commercial aviation industry. In 2007, the YS-11 was added to the Mechanical Engineering Heritage of Japan as item number 13. , 15 were operated by the Japanese military, and two in Mexico. As of 2017, only eight remained in service with the Air Self-Defense Force for flight checks and other purposes. As of July 2018, one aircraft remains in commercial service with Planes For Africa.

Variants

 * YS-11
 * YS-11-100
 * Initial production variant. 23,500 kg (51,810 lb) gross weight. 48 built.


 * YS-11A-200
 * Increased gross weight (24,500 kg (54,010 lb) passenger airliner.


 * YS-11A-300
 * Combi version of YS-11-200, fitted with large cargo door and capable of carrying both passengers and freight.


 * YS-11A-400
 * Pure cargo version of -200, used only by Japanese defence forces.


 * YS-11A-500
 * Passenger airliner with further increased (25,000 kg (55,110 lb)) gross weight produced from 1970.


 * YS-11A-600
 * Combi version of -500.


 * YS-11E
 * JASDF "Super YS" powered by T64-IHI-10J.

Customer variants

 * YS-11-101: TOA Domestic Airlines
 * YS-11-102: All Nippon Airways
 * YS-11-103: Japan Air Self Defense Force
 * YS-11-104: Japan Civil Aviation Bureau
 * YS-11-105: Japan Air Self Defense Force
 * YS-11-106: Japan Domestic Airlines
 * YS-11-107: Filipinas Orient Airways
 * YS-11-108: Japan Domestic Airlines
 * YS-11-109: Japan Domestic Airlines
 * YS-11-110: Japan Civil Aviation Bureau
 * YS-11-111: All Nippon Airways
 * YS-11-113: Japan Maritime Self Defense Force
 * YS-11-114: TOA Airways
 * YS-11-115: Aeronautic College
 * YS-11-116: Filipinas Orient Airways
 * YS-11-117: Hawaiian Airlines
 * YS-11-118: Japan Civil Aviation Bureau
 * YS-11-120: LANSA
 * YS-11-121: Filipinas Orient Airways
 * YS-11-124: Japan Domestic Airlines
 * YS-11-125: Cruzeiro do Sul
 * YS-11-128: Austral (later Austral Líneas Aéreas)
 * YS-11-129: TOA Airways
 * YS-11A-201: NAMC
 * YS-11A-202: Cruzeiro do Sul
 * YS-11A-205: Piedmont Airlines
 * YS-11A-206: Japan Maritime Self Defense Force
 * YS-11A-207: Japan Maritime Safety Agency
 * YS-11A-208: All Nippon Airways
 * YS-11A-209: Southwest Air Lines
 * YS-11A-211: VASP
 * YS-11A-212: VASP
 * YS-11A-213: All Nippon Airways
 * YS-11A-214: Southwest Air Lines
 * YS-11A-217: Japan Domestic Airlines
 * YS-11A-218: Japan Air Self Defense Force
 * YS-11A-219: China Airlines
 * YS-11A-220: Olympic Airways
 * YS-11A-222: TOA Airways
 * YS-11A-223: All Nippon Airways
 * YS-11A-227: Japan Domestic Airlines / TOA Airways
 * YS-11A-301: Korean Air Lines
 * YS-11A-305: Japan Air Self Defense Force
 * YS-11A-306: Transair
 * YS-11A-307: Japan Domestic Airlines
 * YS-11A-309: Aerotransportes Litoral Argentino (later Austral Líneas Aéreas)
 * YS-11A-310: Korean Air Lines
 * YS-11A-313: TOA Airways
 * YS-11A-314: Air Afrique
 * YS-11A-321: Air Gabon
 * YS-11A-402: Japan Air Self Defense Force
 * YS-11A-404: Japan Maritime Self Defense Force
 * YS-11A-500: Piedmont Airlines
 * YS-11A-523: Philippine Civil Aeronautics Administration
 * YS-11A-621: Trans Gabon
 * YS-11A-623: Pelita Air Service
 * YS-11A-624: Japan Maritime Self Defense Force
 * YS-11A-626: Reeve Aleutian Airways

Operators
In July 2011, Transair Cargo, Air Link International Airways, Aero JBR, Aerodan and ALCON Servicios Aereos each operated one YS-11 for a total of five aircraft in commercial service. By July 2018, Aircraft For Africa was the only commercial operator, with one aircraft in service.

Civil operators
Former and present operators of the NAMC YS-11 include:
 * Aboitiz Air
 * Aerodan Cargo (Mexico)
 * Aerolitoral (subsidiary of Aeroméxico)
 * Aero Majestic Airways
 * Aerolíneas Argentinas
 * AeroSierra
 * Air Aruba
 * Air Caribbean
 * Air Nippon (subsidiary of ANA – All Nippon Airways)
 * All Nippon Airways
 * Air Philippines
 * Air Phoenix
 * Air Star Zanzibar (Tanzania – defunct)
 * Midwest Air Charter/Airborne Express (USA)
 * Air Link International Airways
 * Aerotransportes Litoral Argentino (ALA) – merged with Compañía Austral de Transportes Aéreos SACI in 1971 to form Austral Líneas Aéreas
 * ALCON Servicios Aereos
 * American Eagle (operated by Simmons Airlines)
 * Asian Spirit
 * Austral Líneas Aéreas (subsidiary of Aerolíneas Argentinas)
 * Barker-Wayne
 * BIMP - EAGA Air Alliance
 * Bouraq (Indonesia)
 * China Airlines
 * Continental Express (operated by PBA – Provincetown-Boston Airlines, Inc.)
 * Cruzeiro do Sul
 * Far West Airlines (USA)
 * Fil-Asian Airways
 * Fort Worth Airlines
 * Gabon Express, Gabon Express Cargo
 * Gabon (Gabonese Air Force)
 * Gacela Air Cargo
 * Gambia Airways
 * Geological Survey of Japan
 * Global Air Cargo
 * Hawaiian Airlines
 * Hellenic Air Force
 * Interisland Airlines
 * Japan Air Lines
 * Japan Air System (now merged into Japan Airlines)
 * Japan Domestic Airlines (predecessor of Japan Air System)
 * Japan Self-Defense Forces (Air and Maritime)
 * Japan Civil Aeronautics Board
 * Japan TransOcean Air
 * Korean Air
 * Korean Air Cargo
 * Lansa
 * Litoral
 * Mandala
 * Mey-Air
 * Merpati Nusantara Airlines
 * Mid Pacific Air
 * MPAC
 * Nihon Kinkyori Airlines (Subsidiary of ANA – All Nippon Airways)
 * Norcanair
 * Olympic Airways
 * Pacific Southwest Airlines (PSA) – Used to train Japanese pilots. Never painted in PSA livery and were not used in revenue passenger service.
 * Provincetown-Boston Airlines (PBA)
 * Philippine Air Force
 * Philippine Airlines
 * Phuket Air
 * Piedmont Airlines
 * Pinehurst Airlines (USA)
 * Pyramid Airlines (Egypt)
 * Reeve Aleutian Airways
 * Societe Generale d'Alimentation
 * Simmons Airlines
 * South Phoenix Airways
 * Southwest Air Lines Japan (subsidiary of Japan Airlines)
 * Tauk Tours
 * Toa Airways (predecessor of Toa Domestic Airlines)
 * Toa Domestic Airlines (predecessor of Japan Air System)
 * Transair Ltd (Canada)
 * Trans-Central Airlines (USA)
 * Trygon, Ltd.
 * United States Postal Service
 * VASP
 * Winair

Military operators



 * Colombian Army
 * Greek Air Force – 6 ex-Olympic Airways YS-11A aircraft were supplied in 1981.
 * Japan Air Self-Defense Force
 * 401st Tactical Airlift Squadron (1969–1989)
 * 402nd Tactical Airlift Squadron (1968–2001)
 * 403rd Tactical Airlift Squadron YS-11P (1978–2017)
 * Flight Check Squadron YS-11FC
 * Electronic Warfare Squadron YS-11EA
 * Electronic Intelligence Squadron YS-11EB
 * Japan Maritime Self-Defense Force
 * Air Transport Squadron 61 YS-11M/M-A (1971–2014)
 * Japan Coast Guard
 * Japan Maritime Self-Defense Force
 * Air Transport Squadron 61 YS-11M/M-A (1971–2014)
 * Japan Coast Guard

JSDF delivery breakdown: JASDF

2 YS-11EA for Electronic Warfare

4 YS-11EB for ELINT

3 YS-11FC for Flight Checker

1 YS-11NT for Navigation Trainer

3 YS-11P for Passenger/VIP Transport

JMSDF

2 YS-11M for Freighter

2 YS-11M-A for Freighter

6 YS-11T-A for MPA trainer

Incidents
There have been over twenty hull loss accidents involving YS-11 aircraft.
 * 13 November 1966, All Nippon Airways Flight 533 crashed into the sea near Matsuyama, Japan with the loss of all five crew and 45 passengers.
 * 20 October 1969, All Nippon Airways Flight 104 overran the runway at Miyazaki Airport, Japan. All four crew and 49 passengers survived.
 * 11 December 1969, a Korean Air flight from Gangneung to Seoul was hijacked and flown to Sǒndǒk Airfield near Wonsan. The aircraft was damaged on landing and written off. The aircraft, its crew, and seven passengers are still held in North Korean territory.
 * 12 August 1970, China Airlines Flight 206 crashed into Yuan Mountain on approach to Taipei, Taiwan. Two crew and 12 passengers were killed.
 * 1 April 1971, a Merpati Nusantara Airlines YS-11 made a wheels-up landing at Kemayoran Airport, Jakarta Indonesia while on a training flight.
 * 3 July 1971, Toa Domestic Airlines Flight 63 flew into Yokotsu Mountain while on approach to Hakodate Airport, Japan. All four crew and 64 passengers were killed, the worst loss of life in an accident involving the YS-11.
 * 7 November 1971, A VASP YS-11 was destroyed by fire after a candle was lit inside when the aircraft was being guarded overnight after being bogged down at Aragarças Airport in Aragarças, Brazil. Both guards were killed.
 * 12 April 1972, a VASP flight between São Paulo and Rio de Janeiro crashed 50 km north of Rio de Janeiro. All four crew and 21 passengers were killed.
 * 18 October 1972, a Cruzeiro do Sul YS-11 overshot the runway at Congonhas Airport, São Paulo and was damaged beyond repair.
 * 21 October 1972, an Olympic Airlines YS-11 en route from Corfu (Kerkyra) to Athens crashed into the sea in Voula, whilst attempting an approach to Ellinikon International Airport, Athens, in a heavy storm. One crew member (the co-pilot) and 36 passengers were killed, while the captain, the two stewardesses and 16 passengers survived.
 * 23 October 1973, a VASP YS-11 overran the runway at Santos Dumont Airport, Rio de Janeiro after a rejected take-off and ended up in Guanabara Bay. Eight passengers were killed.
 * 5 March 1974, a Pacific Southwest Airlines YS-11 crash landed in the desert 14 km east of Borrego Springs, California while on a training flight. Aircraft was written off.
 * 6 November 1974, a Reeve Aleutian Airways YS-11 was written off in a hangar fire at Anchorage, Alaska.
 * 28 May 1975, TOA Domestic Airlines Flight 621 was damaged beyond repair in a landing accident at Osaka International Airport when a tyre burst and the aircraft departed the runway.
 * 23 November 1976, Olympic Airways Flight 830 an Olympic Airlines YS-11 flew into mountain Metaxas near the village of Servia in Kozani, Greece, in low clouds and almost zero visibility. All four crew and 46 passengers were killed.
 * 29 April 1977, a Cruzeiro YS-11 departed the runway on landing at Ministro Victor Konder International Airport, Navegantes, Brazil.
 * 17 July 1977, a Philippine Airlines YS-11 ditched on approach to Mactan-Cebu International Airport after an engine failure.
 * 11 March 1983, Nihon Kinkyori Airlines Flight 497 undershot the runway at Nakashibetsu Airport, Japan.
 * 13 January 1987, a Mid Pacific Air YS-11 force landed in a field at Remington, Indiana after both engines were mismanaged.
 * 10 January 1988, TOA Domestic Airlines Flight 670 overran the runway at Miho-Yonago Airport, Yonago, Japan after a rejected take-off and ended up in the sea. Aircraft had not been de-iced prior to take-off.
 * 15 March 1989, a Mid Pacific Air YS-11 undershot the runway at Purdue University Airport, Lafayette, Indiana due to loss of pitch control caused by icing on the tail. The aircraft was on a positioning flight, both crew members were killed.
 * 6 March 1992, an Airborne Express YS-11 made a wheels-up landing at Airborne Airpark, Wilmington, Ohio while on a training flight due to pilot error.
 * 24 June 1996, an Air Philippines YS-11 struck a ground power unit while taxiing at Naga Airport, Naga City. Aircraft was destroyed in the subsequent fire.
 * 16 February 2000, Air Nippon Flight 354 departed the runway at Okadama Airport, Sapporo, Japan and collided with a bank of snow.
 * 3 November 2001, a YS-11 being prepared for delivery to an airline in Burundi was destroyed by a fire caused by a stray firework at London Southend Airport.
 * 11 September 2005, Phuket Airlines Flight 326 skids off the runway at Mae Sot Airport, Thailand.
 * 2 January 2008, Asian Spirit Flight 321 suffered an undercarriage collapse on landing at Masbate Airport, Philippines.
 * 28 September 2009, Japanese Maritime Self-Defense Force YS-11M-A serial number 9044 overran the runway upon landing at Ozuki Air Field and was substantially damaged.

Aircraft on display

 * Brazil
 * 2080 – YS-11A-200 on static display as a restaurant in Tijucas, Santa Catarina.


 * Japan
 * 2001 – YS-11 on static display at the Museum of Aeronautical Science in Narita, Chiba. This airframe is the first prototype.
 * 2101 – YS-11A-200 on static display at the Tokorozawa Aviation Memorial Park in Tokorozawa, Saitama.
 * YS-11P 52-1152 is exhibited in the Aichi Museum of Flight in Komaki, Aichi Prefecture.
 * The first mass-produced YS-11 has been in storage at Haneda Airport since 1999, where it has been maintained and kept airworthy by the National Museum of Nature and Science and is occasionally available for public viewing.


 * Philippines
 * 2179 – YS-11A-500 on static display at Philippine Air Force Aerospace Museum in Manila, National Capital.


 * United States
 * 2035 – YS-11-120 on static display at the Grissom Air Museum near Peru, Indiana.