The flaps are the main high-lift units of the aircraft. Pilots release flaps as the plane takes off and land, helping the plane gain more lift. If the pilot forgets to release the flaps, it will bring great safety hazards.
China Northwest Airlines Flight 2119 (WH2119) is a scheduled flight from Yinchuan West Garden Airport in Ningxia to Beijing Capital International Airport. On 23 July 1993, a British Aerospace BAe 146-300 airliner was flying on its route when it was unable to take off due to a mechanical failure, and the aircraft rushed off the runway and crashed into a lake near the airport, killing 55 people and surviving 58.
Northwest Airlines Flight 2119 operates the BAe 146-300 with registration number B-2716. The BAe 146 is a regional airliner manufactured by British Aerospace with a T-tail and front three-point landing gear design. Four Lycoming ALF 502 turbofan engines are suspended under the wings, known for their low noise in the aviation industry, with the title of "Whispering Jet", which is mainly used in regional airports. Between 1978 and 2001, a total of 387 BAe 146 aircraft were produced.
The B-2716 machine was manufactured under the serial number E-3215 and shipped in July 1992. The aircraft age is 1 year, the total aircraft time is 686 hours, and the cumulative number of take-off and landing cycles is 396.
On July 23, B-2716 was scheduled to fly lanzhou-Beijing-Yinchuan-Beijing-Lanzhou. According to the flight plan, the passenger plane took off from Beijing at 11:55 and landed in Yinchuan at 1:41 p.m. After refueling, the aircraft continued to fly on the Beijing route.
Northwest Airlines Flight 2119 carries a total of 108 passengers and five crew members. The captain, who was also a company instructor at the age of 43, began learning to fly in April 1971 and converted the BAe146 model in July 1986. He flew over the Chujiao VI, Yun V, Il-14 and An-24, accumulating 8801 flight hours, of which the BAe146 was 6039 hours. The co-pilot, at the age of 50, learned to fly the same year as the captain and in 1988 converted the BAe146 aircraft. The total number of flights was 6291 hours, of which the BAe146 was 4385 hours.
Ningxia Yinchuan West Garden Airport is an airport in the history of Yinchuan City, first built in 1935 as a military airport, when it was garrisoned by the 168th Division of the 11th Army, and the runway surface was gravel. After the founding of the People's Republic of China, West Garden Airport was renovated and has a runway of 1415 meters long and 40 meters wide for the take-off and landing of Il-14 passenger aircraft. In September 1986, West Garden Airport was renovated and expanded to meet the 3C airport standard. It can be used by aircraft under 50 tons such as BAe146.
The conditions at West Garden Airport were very rudimentary, and it was the only airport in all the provincial capitals of China at that time to use gravel to pave the runway. Moreover, West Garden Airport does not have professional navigation light equipment, and at night the airport only uses horse lamps as navigation lights. In March and April every year, due to the low terrain, the airport runway will be "turned over" due to excessive water accumulation, and the airport will be suspended for more than a month every year. In September 1997, after the opening of Yinchuan Hedong Airport, west garden airport was abandoned.
At 2:40 p.m., Northwest Airlines Flight 2119 was approved by the tower and was ready to glide off the runway. The plane slid to 1777 meters to prepare to look up, and the tail of the aircraft appeared to be ground-grazing. When it slid to 2197 meters, the plane was badly grounded. The plane did not leave the ground until it rushed off the runway.
After rushing out of the runway, the plane ran over a 60-meter-long safety lane and a 50-meter-long grassy road, crossed two drainage ditches, and broke 19 barbed wire cement columns in succession, and finally crashed into a pond on the north side of the runway, about 460 meters from the end of the runway.
After the accident, rescue team members rushed to the scene immediately. After the plane crash, the fuselage became fragmented under the huge impact force and scattered in the pond, which brought great difficulties to the rescue. After an inventory, the search and rescue team found that of the 113 people on board, 55 people were killed and 58 were injured.
Zou Jiahua, then vice premier of the State Council, and Jiang Zhuping, director of the Civil Aviation Administration of China, led a team to Yinchuan to investigate the accident.
Investigators found that before the crash, the B-2716 aircraft and engines were working normally and were in airworthiness. According to the temperature situation at West Garden Airport at that time, the maximum take-off weight of BAe146 was 41.15 tons, and Northwest Airlines Flight 2119 actually carried 41.095 tons, and the aircraft was not overweight. After investigation, the public security organs also ruled out the causes of man-made sabotage.
During their survey of the scene, investigators found that the tail of the aircraft was rubbed three times during the skidding, and there were no signs of brakes and aborts on the runway. After the plane disintegrated, fuel and oil leaked out, and there was no fire at the scene. All four engines were detached from the wings and scattered elsewhere. Investigators found that the flaps of the aircraft were at 0°, the flap indicator was in the "0" position, and the flap joystick was at 24°.
In order to thoroughly understand the truth of the accident, the investigation team also sent the wreckage of the aircraft to the United Kingdom, and the Chinese investigation team inspected it with the assistance of the British Aviation Accident Investigation Agency (AAIB). Investigators found that the flaps of the aircraft were 0° at the time of the incident, and the contents of the pilot's reading of the inspection form were not heard in the voice records. The flap computer non-legacy memory chip has a "4" fault code indicating that the flap is faulty, but the warning board does not show it. The five jump switches of the flap system, including wire connectors, flap control and flap warning, were not found to have problems.
The accident report pointed out that the cockpit voice recording of Flight 2119 of China Northwest Airlines showed that the pilot did not read the inspection form before take-off, nor did he check the position of the flaps, so the flaps were not found to be closed.
Before take-off, although the flap handle is in the 24° position, the 4 jump switches of the cockpit roof flap system are in an open state, at this time the control channel is in the closed position, the flaps cannot be rotated, and the flaps are indicated as 0°. At this time, only by resetting according to the procedure can the pilot retract the flaps normally.
The main causes of the Northwest Airlines Flight 2119 accident were: the pilot violated the regulations, did not perform the inspection order before take-off, and did not look at the position of the flap dial gauge. The plane took off without releasing its flaps, causing the plane to rush off the runway and not pull up.
In the "Nanjing Air Disaster" on July 31, 1992, China General Aviation Flight 7552 crashed during takeoff, because the pilot ignored the checklist procedure and forgot to adjust the flat tail of the aircraft, causing the aircraft to rush off the runway. A year later, China Northwest Airlines Flight 2119 crashed for the same reason.
The Civil Aviation Administration of China has issued repeated orders requiring pilots to strictly implement the inspection order system. But some pilots still see the system as scrap paper, leading to a repeat of avoidable accidents.
In the early 1990s, most of the accidents in China's civil aviation were related to pilots violating regulations and not operating according to procedures. Therefore, the reorganization of airlines and flight teams will be carried out as a top priority in strict compliance with rules and regulations. Starting from the daily execution of tasks, strict discipline makes every pilot develop a rigorous flight style.
In addition, at that time, some pilots did not grasp the technical essentials of the aircraft type, and did not understand the working principle of the on-board equipment. Usually, pilots are busy with flight activities, the learning time is very limited, and it is difficult to improve their skills. Therefore, the flight team is required to be good at "squeezing water in the sponge", create more opportunities for further study, and continuously improve the skill level of flight personnel.