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Description

Link: www.flickr.com/photos/dizzyfug…

Some background:
Although Japan had designed and manufactured a number of military aircraft before and during World War II, it was forbidden according to the Potsdam Declaration from engaging in the production of airplanes and other products that could be used to rearm a military. These restrictions, however, were lightened by the United States during the Korean War, opening up the possibility for a Japanese company to produce a civilian aircraft.

Actually a consortium of several different manufacturing companies and university professors, NAMC was founded in April 1957 by executives from Mitsubishi Heavy Industries, Fuji Heavy Industries, Shin Meiwa Manufacturing, Sumitomo, Japan Aircraft, Showa Aircraft, and Kawasaki Heavy Industries with the goal of designing and manufacturing a Japanese civilian turboprop airliner to replace the successful but aging Douglas DC-3. The resulting aircraft, the YS-11, a low-winged twin-turboprop-engine monoplane, capable of seating up to 60 passengers, became a successful civilian airliner.
On 30 August 1962, the first YS-11 prototype performed its maiden flight. Deliveries commenced on 30 March 1965 and commercial operations began the following month. The majority of orders for the type were issued from various Japanese airliners. While sales to such customers were swift in the YS-11's initial years of availability, this limited market soon became saturated, leading to a slump in demand. By the late 1970s, after producing several variations of the YS-11, NAMC hoped to introduce a jet airliner in order to replace and upgrade the primarily domestic operators and compete with those short-haul airliners being produced in the U.S. by companies such as Boeing and McDonnell Douglas.

This project was called YS-21 and work started in 1968. During the design phase, a high level of attention was paid to market research and operator concerns – even though this was almost exclusively limited to the domestic, Japanese market. Amongst other changes made, the prospective jetliner was increased in size, changing its maximum seating capacity from the YS-11’s 60 to at least 85 passengers in a five-abreast configuration, with a maximum of 100 seats in a tight single-class arrangement.
The aircraft’s general layout resembled the contemporary Boeing 737: a low-wing twin-jet airliner with a conventional tail and podded engines slung under the only slightly swept (just 25°at quarter chord) wings. However, the engines were not directly mounted under the wings, but rather in pods on pylons that set them apart from the wings’ undersurfaces. Fuel was stored within both the outer wings and within the lower fuselage. As a special feature, additional pylon-mounted tanks could be installed under the outer wings for extended range operations if so required.

Special care was taken to allow the aircraft to operate from the same smaller airfields as the YS-11, and various elements of the YS-21 were designed to maximize passenger comfort and operator convenience during operations on 2nd class airfields. One such measure was the rear entry door with built-in stairs that, while adding structural complexity, meant that mobile airport stairs were unnecessary for boarding. In order to ensure operations on smaller airfields and reduce ground pressure, the aircraft received, despite its compact size, four-wheel bogies on its main landing gear. The machine furthermore feature an autonomous power unit (APU) for operations independent from most airfield equipment.

However, a central problem of the YS-21’s development became the powerplant: there was no indigenous engine available to power the aircraft, and developing one at a timely schedule for the YS-21 program turned out to be prohibitively expensive and time-consuming. At one stage of development, NAMC had reportedly intended the YS-21 to be powered by a pair of Bristol Siddeley BS.75 turbofans. However, this selection was hotly contested by rival British engine manufacturer Rolls-Royce, who proposed their Rolls-Royce Spey Junior, a simplified version of the Rolls-Royce Spey.
The engine procurement from foreign sources caused a lot of debate, not only among the NAMC engineers, but also on a political level, since the YS-21 was intended to be a 100% domestic product. Eventually, pragmatism prevailed and the Pratt & Whitney JT8D-9 with thrust reversers and an output of 14,500 lbf (64.50 kN) was chosen, because it was, at the time of the YS-21’s development, to be built under license by Mitsubishi for the Kawasaki C-1 JASDF military jet transport aircraft. A compromise that more or less saved face of the project leaders and the political powers that promoted the aircraft.

A distinctive design trademark of the YS-21 became its engine pods: in order to gain as much ground clearance as possible and keep the landing gear short, the JT8s’ auxiliary installations were mounted to the engines’ sides, resulting in a noticeable bulge on the pods’ outer flanks and a noticeable oval air intake orifice.

Initial domestic market response was quite positive, mostly boosted by national pride, though, and NAMC tried to attract the interest of major national airlines (primarily JAL and ANA, but also smaller companies) and several foreign regional airlines, touting the YS-21 as the better alternative to the foreign Douglas DC-9 or Boeing 737. A few airlines, also from other countries, showed some initial interest but only ANA and JAL placed concrete orders. These were (mis)interpreted as a very positive sign, though, and production was prematurely greenlighted with only 15 firm orders and 10 options in the books.

This lack of interest could be, despite the YS-21’s qualities, contributed to several factors. The main influence was the oil crisis of the 1970s, but another factor was the YS-21’s limited capacity and range – suitable for domestic service in Japan with many short routes, but unattractive for many other potential users. At maximum payload, the aircraft's range was only a mere 1,700 km (a comparable early Boeing 737 had a range of 2.800km), and the optional underwing tanks did not help much since drag and extra weight almost entirely compensated for the potential increase in range. This inherent flaw resulted in a high refueling frequency that grounded the aircraft more often than other types and, as a further effect, relatively high operating costs.

Consequently, the YS-21 achieved no foreign sales, and beyond JAL and ANA as launch customers and main operators of the type, only Japan Transocean Air ordered four machines. With a total of only thirty-three sales and with one of the three prototypes refurbished and sold as the 11th YS-21 to ANA, the airliner represented a severe failure for NAMC and the Japanese commercial airliner industry. Plans for an enlarged version with a stretched fuselage for up to 120 passengers never left the drawing board, since both the domestic and the international markets for short and medium range passenger aircraft were already dominated by other types like the Boeing 727 and 737.

In service, the YS-21 was quickly nicknamed “Karigane” (かりがね; Wild Goose), due to its slender fuselage, the streamlined cockpit section that resembled a goose’s head on a long neck, and the engine nacelles under the rather straight wings, which reminded of the bird’s stretched feet upon landing. This nickname was never officially adopted, though, but frequently used by the crews and in public.

The YS-21 turned out to be a reliable and sturdy aircraft, popular among its crews for its good low speed handling. On 29 April 1995, the last YS-21s in service flew their last commercial flights. Throughout their combined cumulative operational lifetimes, the YS-21s accumulated a total of 1.18 mio. flight hours, during which 80.4 million passengers were carried across 1.3 mio. individual flights, without any accidents and an impressive 98% in-service reliability.

General characteristics:
Crew: 3
Capacity: 85 with 8,400 kg (18,519 lb) payload
Length: 32.40 m (106 ft 1 1/2 in)
Wingspan: 34.3 m (112 ft 6 in)
Height: 10.80 m (35 ft 4 1/2 in)
Wing area: 146.7 m2 (1,579 sq ft)
Empty weight: 22,200 kg (48,943 lb)
Max takeoff weight: 46,000 kg (101,413 lb)

Powerplant:
2× Mitsubishi-built Pratt & Whitney JT8D-9 low bypass turbofans, 64 kN (14,500 lbf) thrust each

Performance:
Maximum speed: 590 mph (950 km/h, 510 kn) at 6,100 m (20,000 ft)
Cruise speed: 470–530 mph (750–850 km/h, 400–460 kn) at 6,100 m (20,000 ft)
Range: 1,700 km (1,100 mi, 920 nmi)
Service ceiling: 12,000 m (39,000 ft)
Rate of climb: 16.7 m/s (3,300 ft/min) at 2,135 m (7,005 ft)
Takeoff roll: 1,859 m (6,099 ft)
Landing roll: 1,755 m (5,670 ft)

Description

Link: www.flickr.com/photos/dizzyfug…

Some background:
Although Japan had designed and manufactured a number of military aircraft before and during World War II, it was forbidden according to the Potsdam Declaration from engaging in the production of airplanes and other products that could be used to rearm a military. These restrictions, however, were lightened by the United States during the Korean War, opening up the possibility for a Japanese company to produce a civilian aircraft.

Actually a consortium of several different manufacturing companies and university professors, NAMC was founded in April 1957 by executives from Mitsubishi Heavy Industries, Fuji Heavy Industries, Shin Meiwa Manufacturing, Sumitomo, Japan Aircraft, Showa Aircraft, and Kawasaki Heavy Industries with the goal of designing and manufacturing a Japanese civilian turboprop airliner to replace the successful but aging Douglas DC-3. The resulting aircraft, the YS-11, a low-winged twin-turboprop-engine monoplane, capable of seating up to 60 passengers, became a successful civilian airliner.
On 30 August 1962, the first YS-11 prototype performed its maiden flight. Deliveries commenced on 30 March 1965 and commercial operations began the following month. The majority of orders for the type were issued from various Japanese airliners. While sales to such customers were swift in the YS-11's initial years of availability, this limited market soon became saturated, leading to a slump in demand. By the late 1970s, after producing several variations of the YS-11, NAMC hoped to introduce a jet airliner in order to replace and upgrade the primarily domestic operators and compete with those short-haul airliners being produced in the U.S. by companies such as Boeing and McDonnell Douglas.

This project was called YS-21 and work started in 1968. During the design phase, a high level of attention was paid to market research and operator concerns – even though this was almost exclusively limited to the domestic, Japanese market. Amongst other changes made, the prospective jetliner was increased in size, changing its maximum seating capacity from the YS-11’s 60 to at least 85 passengers in a five-abreast configuration, with a maximum of 100 seats in a tight single-class arrangement.
The aircraft’s general layout resembled the contemporary Boeing 737: a low-wing twin-jet airliner with a conventional tail and podded engines slung under the only slightly swept (just 25°at quarter chord) wings. However, the engines were not directly mounted under the wings, but rather in pods on pylons that set them apart from the wings’ undersurfaces. Fuel was stored within both the outer wings and within the lower fuselage. As a special feature, additional pylon-mounted tanks could be installed under the outer wings for extended range operations if so required.

Special care was taken to allow the aircraft to operate from the same smaller airfields as the YS-11, and various elements of the YS-21 were designed to maximize passenger comfort and operator convenience during operations on 2nd class airfields. One such measure was the rear entry door with built-in stairs that, while adding structural complexity, meant that mobile airport stairs were unnecessary for boarding. In order to ensure operations on smaller airfields and reduce ground pressure, the aircraft received, despite its compact size, four-wheel bogies on its main landing gear. The machine furthermore feature an autonomous power unit (APU) for operations independent from most airfield equipment.

However, a central problem of the YS-21’s development became the powerplant: there was no indigenous engine available to power the aircraft, and developing one at a timely schedule for the YS-21 program turned out to be prohibitively expensive and time-consuming. At one stage of development, NAMC had reportedly intended the YS-21 to be powered by a pair of Bristol Siddeley BS.75 turbofans. However, this selection was hotly contested by rival British engine manufacturer Rolls-Royce, who proposed their Rolls-Royce Spey Junior, a simplified version of the Rolls-Royce Spey.
The engine procurement from foreign sources caused a lot of debate, not only among the NAMC engineers, but also on a political level, since the YS-21 was intended to be a 100% domestic product. Eventually, pragmatism prevailed and the Pratt & Whitney JT8D-9 with thrust reversers and an output of 14,500 lbf (64.50 kN) was chosen, because it was, at the time of the YS-21’s development, to be built under license by Mitsubishi for the Kawasaki C-1 JASDF military jet transport aircraft. A compromise that more or less saved face of the project leaders and the political powers that promoted the aircraft.

A distinctive design trademark of the YS-21 became its engine pods: in order to gain as much ground clearance as possible and keep the landing gear short, the JT8s’ auxiliary installations were mounted to the engines’ sides, resulting in a noticeable bulge on the pods’ outer flanks and a noticeable oval air intake orifice.

Initial domestic market response was quite positive, mostly boosted by national pride, though, and NAMC tried to attract the interest of major national airlines (primarily JAL and ANA, but also smaller companies) and several foreign regional airlines, touting the YS-21 as the better alternative to the foreign Douglas DC-9 or Boeing 737. A few airlines, also from other countries, showed some initial interest but only ANA and JAL placed concrete orders. These were (mis)interpreted as a very positive sign, though, and production was prematurely greenlighted with only 15 firm orders and 10 options in the books.

This lack of interest could be, despite the YS-21’s qualities, contributed to several factors. The main influence was the oil crisis of the 1970s, but another factor was the YS-21’s limited capacity and range – suitable for domestic service in Japan with many short routes, but unattractive for many other potential users. At maximum payload, the aircraft's range was only a mere 1,700 km (a comparable early Boeing 737 had a range of 2.800km), and the optional underwing tanks did not help much since drag and extra weight almost entirely compensated for the potential increase in range. This inherent flaw resulted in a high refueling frequency that grounded the aircraft more often than other types and, as a further effect, relatively high operating costs.

Consequently, the YS-21 achieved no foreign sales, and beyond JAL and ANA as launch customers and main operators of the type, only Japan Transocean Air ordered four machines. With a total of only thirty-three sales and with one of the three prototypes refurbished and sold as the 11th YS-21 to ANA, the airliner represented a severe failure for NAMC and the Japanese commercial airliner industry. Plans for an enlarged version with a stretched fuselage for up to 120 passengers never left the drawing board, since both the domestic and the international markets for short and medium range passenger aircraft were already dominated by other types like the Boeing 727 and 737.

In service, the YS-21 was quickly nicknamed “Karigane” (かりがね; Wild Goose), due to its slender fuselage, the streamlined cockpit section that resembled a goose’s head on a long neck, and the engine nacelles under the rather straight wings, which reminded of the bird’s stretched feet upon landing. This nickname was never officially adopted, though, but frequently used by the crews and in public.

The YS-21 turned out to be a reliable and sturdy aircraft, popular among its crews for its good low speed handling. On 29 April 1995, the last YS-21s in service flew their last commercial flights. Throughout their combined cumulative operational lifetimes, the YS-21s accumulated a total of 1.18 mio. flight hours, during which 80.4 million passengers were carried across 1.3 mio. individual flights, without any accidents and an impressive 98% in-service reliability.

General characteristics:
Crew: 3
Capacity: 85 with 8,400 kg (18,519 lb) payload
Length: 32.40 m (106 ft 1 1/2 in)
Wingspan: 34.3 m (112 ft 6 in)
Height: 10.80 m (35 ft 4 1/2 in)
Wing area: 146.7 m2 (1,579 sq ft)
Empty weight: 22,200 kg (48,943 lb)
Max takeoff weight: 46,000 kg (101,413 lb)

Powerplant:
2× Mitsubishi-built Pratt & Whitney JT8D-9 low bypass turbofans, 64 kN (14,500 lbf) thrust each

Performance:
Maximum speed: 590 mph (950 km/h, 510 kn) at 6,100 m (20,000 ft)
Cruise speed: 470–530 mph (750–850 km/h, 400–460 kn) at 6,100 m (20,000 ft)
Range: 1,700 km (1,100 mi, 920 nmi)
Service ceiling: 12,000 m (39,000 ft)
Rate of climb: 16.7 m/s (3,300 ft/min) at 2,135 m (7,005 ft)
Takeoff roll: 1,859 m (6,099 ft)
Landing roll: 1,755 m (5,670 ft)