Y-7

The Xian Y-7 is a Chinese copy of Antonov An-24; versions include Y-7, Y-7-100, Y-7-100J, Y-7G, Y-7H (was Y-14), Y-7-200A and Y-7-200B. Xian Aircraft builds the Y-7 transport plane, designed to operate on medium-and short-distance feeder lines, with a passenger cabin that accommodates 48-52 seats. All domestic Chinese airlines rely on the Yun-7 passenger planes produced by Xi'an Aircraft as the mainstay for intermediate and short flights, as well as branch routes.

In civilian aircraft, the Y-7 turboprop was able to win only a limited number of domestic orders. Since the first delivery of a Y-7 to the Shanghai Civil Aviation Bureau in December 1983, a total of 18 Y-7s had been in operation on a number of domestic air routes by April 1987. In the year 2000, just 64 of the Y-7s were in service in thirteen domestic airlines. In addition, the People's Liberation Army used the Y-7 as a transporter. Export orders were negligible. By the late 1990s, a total of only 130 Y-7s had been produced, and new orders had dried up completely. To compound matters, in the year 2000, a Y-7 exploded in mid-air. Following the conclusion of the crash investigation, all Y-7s were taken out of service in June 2001.

Before 2015, China would be able to deliver its own turbo-prop regional jet series of the MA60, MA600, MA700 catered to different users. A total of 1,900 turboprops will be sold around the world in the next 20 years, authorities predicted. Turbo propeller regional aircraft are commonly used on short and medium range flights. Nearly half of the regional jets flying in Europe and North America are turbo-propelled. The demand for the relatively environment-friendly aircraft is expected to rise with global oil prices.

By the mid-1960s China had adjusted its national economy and began its performance of the Third Five-year Plan. With the development of domestic air transportation, a domestic commuter airplane was thus needed. At this time the aviation industry had had years of experience in production of small transports, a factory for production of medium bombers had been constructed and a large airliner design institute had also been established. It was the right time to develop a domestic commuter airplane.

In October 1966 Premier Zhou Enlai and Vice Chairman Ye Jianying approved the design concept of the Y-7. After the assignment of the development task a design team was formed, which was composed of three aircraft factories in Xi'an, Nanchang and Chengdu and the Xi'an Aircraft Design Institute. The design team was headed by Li Xipu, vice chief engineer of the Xi'an Aircraft Factory. Xu Shunshou, vice director of the Xi'an Aircraft Design Institute was appointed its deputy leader. One of the ground rules for the design was to utilize domestic materials, vendor-furnished-equipment and components and accessories to the maximum. Designers worked very hard in a strong wish to develop our own civil airplane and finished the design drawings and specifications in March 1968. The prototype production began in October 1969 and the final assembly in early December 1970. The first flight of the Y-7 piloted by Li Benshun air crew took place on December 25.

The Y-7 was composed of 16,963 kinds of parts, 500,000 standard parts in 5,248 kinds, 520 kinds of vendor-furnished-equipment and components, of which 246 kinds were new, and 2,135 kinds of metal materials. A lot of advanced manufacturing techniques were required and among them were integral panel, shot peen forming, titanium alloy forming, aluminium alloy spot-weld bonding, integral fuel tank construction, stretch forming for the orientated acrylic plastic sheet, etc. It was really not easy to solve all the problems related with these advanced manufacturing techniques and to send a commuter airplane into the sky in less than five years.

"It is not easy to reach the stage of flight and even more difficult to be certificated." The Y-7, as a civil passenger airplane with more emphasis on safety, economics, comfortability and operational life, needed more ground and flight tests. But it was in the time of turmoil and it was difficult to carry out all the development activities. That was why the Y-7 could not be certificated for mass production for a long time after its first flight. The Y-7 development was sped up until the normal production order was restored in 1977.

In 1980 in order to solve the problem related to engine starting at high altitude and high temperature the higher rated engines WJ5A-1 s were used. The followed flight tests accumulated 1,600 hours. The airfields operated were in 28 provinces and cities and among them were the high altitude airfields, high temperature airfields and unpaved airstrips. These flight tests ,`=showed that the aircraft controllability, safety, engine starting behavior at high altitude and high temperature airfields and airworthiness with the passengers onboard were all good and were in conformity with the design requirements.

To be highly responsible for passengers' safety and to ensure the airplane's safe flying in any conditions the Y-7 was tested with one engine inoperative in takeoff and landing. This was a high risky and technically complicated test which had never been carried out in our country. The purpose of the test was to verify the aircraft ability of normal takeoff and landing when one of two engines was damaged or out of control. The flight test was jointly administrated by the MAI and CAAC on April 4, 1982 at Zhangguizhuang airfield, Tianjin. Commanded by. He Wenzhi, Vice Minister of MAI, a six-member air crew including Zhang Yun, captain of the 8th brigade of CAAC, and Cheng Yuanyong, executive captain, successfully carried out single engine takeoff and landings with takeoff weight of 19,200 kg and 21,000 kg and created a first Chinese record.

On April 16 Vice Premiers Geng Biao and Zhang Aiping had an interview with the flight test members. The MAI and CAAC awarded merits and prizes to the people who had rendered outstanding services to the Y-7 single engine flight test. Zhang Yun, Cheng Yuanyong and Zhang Qinliang, the leader of the technical group for the Y-7 flight test of Xi'an Aircraft Company, honourably won the first class merits. In July 1982, the government approved the design certification of the Y-7 for pre-production.

The Y-7 is a monoplane with high set wing and low-mounted tailplane. Two WJ5A-1 turboprop engines are mounted at inboard wings. The cabin normally accommodates 48-52 passengers. In addition there are also a mixed passenger-cargo version and a freighter version. The Y-7 can also be retrofitted for aerial survey and mapping and natural resource exploration.

To further improve the safety, reliability, passenger comfortability and economics, the Xi'an Aircraft Company cooperated with Hong Kong Aircraft Engineering Company (HAECO) in 1985 in refurbishing the Y-7 with foreign advanced technology and equipment. The Y-7 was retrofitted with 30 advanced communication and navigation equipment, winglets, new cabin interior for lowering cabin noise, new three-man flight deck layout instead of original five-man layout, new cabin air conditioning and pressure regulation system and new style pain�ting. It was considerably improved and its airworthiness flight test carried out on long distance air route in our country showed the following improvements: the equipment MTBF was significantly increased; the fuel consumption was reduced by 3-4 percent; the cabin noise level was reduced by 5-6 EPNdB, the passenger uncomfortable feeling caused by the pressure difference was basically eliminated; and the cabin interior was more beautiful and comfortable. Therefore, the Y-7 had more favourable airworthy capability to operate at various regions in China and was awarded a certificate of airworthiness by CAAC on January 23, 1986.

The China-developed Y-7 airplane succeeds in its first passenger flight on April 29, 1986, the first China-developed aircraft to do so. The successful flight marked the end of the period of relying on foreign airplanes for China's civil air passenger service.

Y-14 / Y-7H / Y7H-500

The first flight of the prototype military (Y7H) and civil (Y7H-500) cargo transport was in late 1988. Originally known as the Y-14-100, the Y7H-500 first flight was 24 March 1992; the domestic civil type certificate 30 December 1993, followed by series production certificate 15 June 1994. Three prototypes were built by January 1995.

Y7H-500 aircraft is a short-medium range cargo aircraft. The flight crew consists of a pilot, a copilot and a flight engineer. The cargo compartment is fully pressurized. Y7H-500 aircraft can perform cargo transportation, carry personnel and perform air dropping. It can also execute aerial mapping, geological prospecting, air seeding, artificial rain-making and forest fire-fighting.

Y7H-500 aircraft is equipped with two WJ5E turboprop engines as the main power plant. The maximum power of one engine is 3050 horse power. A PY19A-300 turbojet engine with maximum thrust of 900KG is used as the boost engine. The advanced communication, navigation system and auto-pilot are installed on the aircraft. It is adaptable for different airports, and can accomplish flight missions under severe weather conditions day and night. It is able to take-off with full load in "high and hot" conditions. Y7H-500 aircraft has a good performance in aircraft stability and controllability. It fully meets the demand of commuter transportation.

An electric winch and hydraulic conveyer are installed in the cargo compartment. On the rear section of the fuselage a big cargo door is provided for loading and unloading the cargo. Operation of the cargo can be realized by the following three ways: NORMAL, EMERGENCY and MANUAL. During setting the door to either "DOWN" or "BELLY" position, it can be stopped at any intermediate position. Y7H-500 aircraft features low cost, wide application and high adaptability.