On February 9, China Eastern Airlines flight MU2287 from Xi'an to Yulin Yuyang Airport was unsafe, and the aircraft was grounded outside the runway, and some components were damaged. According to upstream news, the flight was carried out by An airbus A320 aircraft, numbered B-305Y, which took off from Xianyang International Airport at 7:52 a.m. on the same day and landed at Yulin Yuyang Airport after 50 minutes of flight.
Airbus A320 aircraft numbered B-305Y
The dangerous situation occurred when the flight landed, the aircraft was grounded in advance outside the runway of Yulin Airport, and the tire collided with the airport lamp, resulting in damage to the lamp and some components of the aircraft, which should be a tire according to the analysis. However, the damage was not serious, the aircraft still landed safely, there were no casualties among passengers, and the subsequent flight was delayed by more than 6 hours due to the replacement of the aircraft.
Is this matter serious or not? It depends. Runway grounding, also known as "off-field grounding", means that the aircraft did not land accurately on the runway, but fell off the runway and made unplanned contact with the ground. Obviously, this is an unsafe state, and the aircraft may crash into equipment, buildings, etc. outside the runway, according to professional pilots: "This may cause fuselage damage, casualties and other accidents." ”
Flight software data
However, the level of runway external grounding is not enough to be "accident", according to the provisions of the "Civil Aviation Syndrome Classification Measures", civil aviation passenger aircraft in take-off or landing, rushing out, deviating out of the runway or runway external grounding is second only to flight accidents "transport aviation serious syndrome". Whether the early grounding incident of the passenger plane of China Eastern Airlines is a serious symptom of transport aviation needs to be further investigated by the regulatory authorities.
Although the incident did not cause casualties and the damage to aircraft and runway equipment may have been relatively minor, it was still enough to raise concerns. This indicates the possibility that one is that there is a problem with the operation of the crew, which descends too fast during approaching, causing the aircraft to touch the ground before it reaches the runway area; the other is that there is a problem with the equipment on the aircraft, such as the radio altimeter, and the altitude is misjudged.
Yulin Yuyang Airport
The role of the radio altimeter is to measure the vertical distance from the aircraft to the ground and is a very important aircraft instrument. Its principle is similar to that of radar, which determines the altitude off the ground by transmitting a radio signal to the ground and then receiving the signal. Civil aircraft generally use low-altitude radio altimeters with a measurement range of -20 to 2500 feet, usually used during the approach and landing phases of the aircraft.
If there is an error in the display of the radio altimeter, and the altitude is higher than the actual value, it is possible to make the pilot think that the aircraft is still far from the ground, and thus make a mistake. However, as a pilot who has experienced hundreds of battles, the aircraft has been trained many times, and the weather in Yulin on February 9 is cloudy, and if the line of sight is good during the day, there should be no misjudgment, so it cannot be ruled out that the pilot is not concentrated or negligent when landing.
Renma Jun's inquiry found that this is not the first time that China Eastern Airlines has appeared on the outer ground of the runway. On May 1, 2016, an A319 passenger plane of China Eastern Airlines (no. B-6430) flew from Chengdu to Kangding, and when it was grounded at Kangding Airport, the runway was grounded, six lights in four rows of the airport were damaged, a set of hydraulic oil on the passenger plane was almost leaked, the right horizontal tail was broken by runway lights, the plane was forced to return to Chengdu, and the runway lights of Kangding Airport were also brought to Chengdu dramatically.
Pierced horizontal tail
Afterwards, it was found that the visibility of Kangding Airport was not high on the same day, and the crew did not implement the relevant regulations for landing at Plateau Airport (Kangding Airport was more than 4200 meters above sea level), did not arrange double captains, did not use oxygen, and did not see the runway after passing the decisive height, did not return to the sea and continued to approach, resulting in the outer grounding of the runway. The incident was classified as a serious accident and two captains were revoked their flight licences.
Coincidentally, not only China Eastern Airlines, on October 16, 2020, Shenzhen Airlines flight ZH9247 also had an off-site grounding incident, the same A319 passenger plane, landed outside the runway when landing at Panzhihua Airport, causing two damages in the fuselage that were 20×12×3.2 and 45×5× transition (cm), the aircraft tires were damaged in many places, and the airport runway approach lights and navigation monitoring antennas were damaged and broken by the aircraft.
The fuselage of the Shenzhen Airlines aircraft was damaged
In foreign countries, runway grounding also occurs from time to time, sometimes more serious, for example, on December 2, 2020, a Djibouti Aircraft type 737-500 grounded off-site when it landed, directly breaking the main landing gear, fortunately the passenger was not injured. Although the grounding outside the runway was not an accident, and the incident of China Eastern Airlines did not cause casualties, there was already a great danger, and once the situation deteriorated, it was also possible to cause aircraft destruction and death.
For example, in the 2010 Yichun 8.24 air disaster, a Henan Airlines ERJ-190 aircraft landed at Lindu Airport in Yichun City, Heilongjiang Province, crashed at a distance of 690 meters from the runway, killing 44 people. The accident was caused by a controlled flight crash to the ground, which was caused by a pilot's error and continued approach without being able to see the runway clearly. Afterwards, the captain was sentenced to 3 years in prison.
The Yichun air disaster that killed 44 people
It can be seen that although the grounding outside the runway may not cause casualties, it is a precursor to a major flight accident, and if it continues to develop, it may be an air crash in which aircraft is destroyed and killed. Therefore, after the investigation of the causes of this incident is clear, it must be taken seriously, and the alarm bells must be sounded to prevent more serious accidents.