Sichuan Airlines' "May 14" Incident Investigation Report Announces that
Captain Hero Drived at Low Altitude for 20 Minutes
Hero Captain Liu Chuanjian
Sichuan Airlines' "May 14" incident investigation report showed that the cause of the incident was that the aircraft's right windshield seal may be damaged.
Sichuan Airlines' "May 14" incident investigation report was released. This 131-page investigation report not only disclosed the cause of the incident, but also disclosed for the first time more details of the whole process of the incident and the "Hero Captain" Liu Chuanjian's response to the incident.
According to the report, the reason for the Sichuan Airlines May 14th incident is that the aircraft’s right windshield seal (weather seal or silicone seal) may be damaged and cannot withstand the pressure difference between the inside and outside of the cockpit. After the incident, Captain Liu Chuanjian also flew 19 minutes and 54 seconds in a high altitude hypoxic environment.
Full disclosure of the incident for the first time: First class pillow found in Ya'an
The investigation report disclosed for the first time the complete incident of the "May 14" incident. The Civil Aviation Administration of China believes that the Sichuan Airlines "May 14" incident constitutes a serious symptom of transportation aviation.
On May 14, 2018, Airbus A319-133/B-6419 of Sichuan Airlines Co., Ltd. performed flight 3U8633 from Chongqing to Lhasa, with 119 passengers on board and 9 crew members. During the flight of the aircraft, the right windshield of the cockpit burst and fell off, the aircraft lost pressure, the passenger oxygen mask fell off, the crew declared the highest level of emergency (Mayday), and the aircraft was landed in Chengdu. The incident caused one minor injury and one minor injury. The aircraft cockpit, engine, and external skin were damaged to varying degrees.
At 6:27 on May 14, 2018, the plane took off from Chongqing Jiangbei Airport, captain Liu Chuanjian served as the captain in charge, and the right-hand co-pilot was Xu Ruichen.
At 7:7:5, when the cockpit height of the aircraft was 6272 feet, a muffled noise appeared in the sound recorder of the aircraft cabin. The crew found a radial mesh crack in the right windshield. All cracked."
At 7:7:10, the sound of "Boom" appeared for the second time in the cabin sound recorder. Captain Liu Chuanjian immediately said "I operate."
At 7:7:45, the windshield of the aircraft burst at 6,256 feet, continuous noise appeared in the cabin sound recorder, and the aircraft was automatically piloted off. The captain manually controlled the aircraft and began to descend. During the descent of the aircraft, alarm messages appeared many times, and the crew's contact with the ground was also interrupted. The flight area control continued to call the crew through various means, but no response was received.
At 7:19, the 3U8633 crew announced the distress signal MAYDAY twice in the frequency, and the district management responded. The aircraft resumed contact on the ground, and the aircraft continued to fly to Chengdu Airport in preparation for landing.
At 7:41, Liu Chuanjian drove flight 3U8633 on runway 02R of Chengdu Shuangliu Airport, and some of the aircraft's tires punctured.
After the incident on May 14, the Civil Aviation Administration of China immediately intervened in the investigation. The investigation team checked the B-6419 aircraft and found that the right windshield of the cockpit was missing, the flight control components were tilted upwards to the right, some components in the cockpit were missing, the co-pilot Xu Ruichen’s headset and flight attendant boarding pass were lost, and the captain’s electronic Flight manuals are lost, first-class curtains and first-class pillows are lost. Check the landing gear area. The fusible plugs of the main wheels No. 3 and 4 on the right are melted, the tire is relieved of pressure, and the tire skin is intact.
According to the report, on July 26, 2019, local residents in Baoxing County, Ya'an City found a missing aircraft component on a high mountain at 4273 meters above sea level. First-class pillows were also found.
Disclosure of "Hero Captain" handling details: high altitude hypoxic flight for nearly 20 minutes
The investigation report disclosed more details of "Captain Hero" Liu Chuanjian's response to the incident.
After the aircraft's right windshield cracked for the first time, the first officer immediately searched for relevant information in the electronic flight manual. The left seat captain Liu Chuanjian immediately touched with his hand and judged that there was a crack on the inside. After the crew received the control instruction, the captain immediately executed the descent procedure. During the descent process, when the co-pilot searched for the relevant program, the right windshield fell off, the cockpit was explosively depressurized, and the crew turned to handle the cabin decompression.
The windshield fell off resulting in an explosive cockpit pressure loss. The co-pilot was immediately taken away from the seat by a powerful leaking airflow. At this time, the right seat side bar appeared forward, and the autopilot was disconnected. The aircraft's attitude changed suddenly and the captain immediately manipulated it immediately. aircraft.
Captain Liu Chuanjian tried to remove the oxygen mask with his right hand, but because the left hand manipulated the side lever, the oxygen mask was located on the left rear side of the body, and the aircraft was shaking violently. The main energy was used to control the state. The right hand failed to remove the oxygen mask. Captain Liu Chuanjian did not wear an oxygen mask from the windshield bursting to the aircraft landing. It was exposed to an anoxic environment at altitudes above 10,000 feet in the cabin for 19 minutes and 54 seconds.
The investigation report showed that after entering the cockpit, the second captain Liang Peng signaled the co-pilot to recognize the transponder by patting his shoulders. Immediately after discovering that the captain did not wear an oxygen mask, captain Liu Chuanjian learned through the second captain that the cabin conditions were normal. During the descent process, using the handheld microphone to send the air traffic controller "MAYDAY" "cabin pressure" and other critical distress information and crew intentions; the second captain communicated with the captain and the co-pilot by patting the shoulder and other methods to encourage each other The second captain rubbed the shoulders and arms for the captain and co-pilot from time to time to ease the discomfort caused by the cold. "During the incident handling process, the crew showed strong cockpit management capabilities."
From May 14 to May 15, 2018, three flight crew members Liu Chuanjian, Liang Peng and Xu Ruichen conducted electrical audiometry examinations at the First People’s Hospital of Chengdu. The hearing of the captain and co-pilot declined, and the second aircraft There was no obvious abnormality in the long. The first officer was diagnosed as "high-frequency mild sensorineural deafness (high air pressure injury)" after examination in the hospital. After landing, the crew of 3 people successively experienced dizziness, bloating, scalp numbness, muscle aches and other symptoms. The second captain had two red spots under the skin of his right forearm. These may be symptoms of high altitude decompression sickness. After more than 20 hyperbaric oxygen cabin treatments for 3 crew members, the symptoms were significantly improved and recovered well.
Investigation of the cause of the incident: the right windshield of the aircraft may be damaged
The investigation team of the Civil Aviation Administration concluded that the windshield glass burst. The most likely cause of this incident is: the right windshield seal of B-6419 (weather seal or silicone seal) may be damaged, there is a cavity inside the windshield, and external water vapor Infiltrated and remained on the bottom edge of the windshield. After long-term immersion of the power cord, the insulation decreases, and a continuous arc discharge in a humid environment appears at the lower left corner of the windshield. The local high temperature generated by the arc causes the double-layer structure glass to break. The windshield cannot withstand the pressure difference between the inside and outside of the cockpit and burst off from the fuselage.
The investigation revealed that the right windshield of B-6419 was an original Airbus company. There were no abnormal records in manufacturing and installation, no abnormal maintenance records, no abnormal maintenance history, no fault retention on the day, and no damage reports during the pre-flight inspection. The investigation team ruled out the possibility of windshield rupture due to improper maintenance.
The incident report made safety recommendations to the aircraft manufacturer Airbus, including recommending that Airbus establish a failure mode based on the Sichuan Airlines “5·14” events and similar events in history, evaluate and improve windshield design, material selection and manufacturing processes to prevent water vapor intrusion and retention In the electric heating system, reduce the possibility of arc generation and avoid double-layer structure glass breakage; study to increase the detection and protection functions of the arc in the windshield heating system, suggest that Airbus urge the windshield manufacturer to strengthen the quality control of windshield production, Ensure that windshield manufacturing continues to meet design standards and manufacturing process specifications.