Who can introduce the 5.8 air crash of China Southern Airlines?

1. What happened?

On the same day, 2925/kloc-0 took off from Chongqing jiangbei airport at 9: 45, and is expected to arrive at Shenzhen huangtian airport at 2 1: 30, and establish contact with Shenzhen airport approach control at 2 1: 07, and approach runway 33 according to normal procedures. 2 1: 17 establish contact with the tower. The tower told the crew that it was raining heavily on five sides. Call when you see the runway. 2 1: 18: 07, the crew reported that "the blind landing has been established", 2 1: 18: 53, the crew reported that "the entrance light was seen", and the tower commanded the aircraft to "check the landing". Near the aircraft approach platform, the tower saw the landing light of the aircraft, but the light was not clear in the rain. The ground radar shows that the flight path and descent altitude of the aircraft are normal. The plane landed at the southern end of the runway for the first time. After grounding, the plane jumped three times and then went around. Turn left after going around and rise to 1200m. The tower reminded the crew to turn on the transponder, but it was not displayed on the secondary radar. 2 1: 23: 57, the crew reported that it was in a trilateral position and asked other aircraft to avoid it. 2 1: 23: 40, the crew once again asked other aircraft to avoid and reported an emergency, and various warnings appeared in the cockpit. The tower told me that other planes had been told to avoid. 2 1: 24: 58 The crew requested to use fire engines and ambulances after landing, and the tower informed the crew that everything was ready. Then the plane made another turn and reported that it was going to land south. The tower agreed to land to the south, and told the 2925 troops that "the troops landing ahead reflected that the weather was fine in the north and it rained heavily on five sides in the south". The unit answered clearly and said, "I'm going to land." The landing time is 2 1: 28: 30. After landing, the plane disintegrated and caught fire.

2. Field test

(1) made its first landing from south to north. After entering the runway, the first small tire fragment was found at a distance of 388.5 meters from the southern end of the runway. The first metal fragment was found 502 meters away from the southern end of the runway. It is 56 1 m from the south end of the runway and 25m from the left side of the runway centerline. It was found that 1 tire was 54 cm long and 28 cm wide, showing a tear-like tire. 570 meters from the southern end of the runway and 20 meters to the left of the center line, the left wheel blade of the front landing gear was found, which was 46 cm long and 2 1 cm wide. 580.5 meters away from the southern end of the runway, near the center line, the electromagnetic valve of the anti-skid brake of the main wheel of the aircraft was found. Near the center line of 80 1 m at the southern end of the runway, the inner ring of the left hub of the front landing gear was found (the edge was irregularly broken). The above situation shows that the left front wheel exploded after the front wheel touched the ground when the plane landed for the first time, and debris was scattered on the runway.

At the southern end of the runway from 388m to 80 1 m, there are many rivets (mostly shear marks) on the pavement, and a small amount of scattered objects such as metal sheets, hoses and fixing clips. The above situation shows that the aircraft structure was damaged during the first landing.

(2) After the plane went around, it landed from north to south for the second time. After entering the runway, it is 427.2 meters away from the north end of the runway and 4.5 meters to the right of the center line, and there are obvious scratches on the lower part of the fuselage. On the right front of this mark, 4.8 meters to the right of the center line of the fuselage scratch, there is a right engine scratch. There is a left engine scratch at the left front of the lower fuselage scratch and 4.9 meters to the left of the fuselage scratch center line. At the distance of 44 1 m from the north end of the runway, there are three obvious grooves near the center line of the road, with the deepest depth of 2 cm and the widest width of 12 cm. It is verified that these three grooves are groove marks caused by the left axle (left side) of the front landing gear, the lug of the tractor and the steering actuator of the front wheel.

After the plane scraped the ground, it was dragged for about 600 meters and then disintegrated. The trailing edge of the middle right wing of the aircraft was severely burned, and there were scattered objects such as nose landing gear, flaps, slats, luggage racks and cabin seats near the center line or side of the runway at 1.200m and 1.05.7 m from the north end of the runway: the length of the front section of the fuselage 12m, partially damaged, with rolling but no burn marks. The nose is facing north, the cockpit is partially deformed, there is a lot of mud on the instrument panel and center console, the landing gear handle is in neutral position, the lower part of the nose is sunken, and the lower part of the weather radar antenna is bent backwards. From the north end of the runway 1370 meters, 79.4 meters to the right of the runway center line, the rear fuselage is relatively complete. The left main landing gear and the right engine are scattered on the left side of the runway. The bottom of the left engine is badly worn, and the fan blades are partially broken and partially bent. The right main landing gear is scattered on the right side of the runway. The tire inside the right main landing gear exploded, and the bottom of the right engine was badly worn. Within the range of about 1230 m× 250 m, aircraft wreckage and scattered objects are distributed on the road surface north of the central circle of the runway and on the grass on both sides.

3. The crew's technical and physical condition

(1) technical situation

Captain: Lin (left), male, born in July 2005, 1960, weather standard:12. The total flight time is 12738: 08 hours, including 9084: 5 1 hour for operators and 3654: 12 hours for pilots.

Type of aircraft flying: TB-20( 120 hours), Y-7 (52: 14 hours).

Current model: Boeing 737-300 flying 3482: 04 hours (solo flying 22 hours).

1996 65438+passed the technical inspection on February 29th.

Co-pilot: Kong Dexin (right seat), male,1born in April 1952, weather standard: 1/2. The total flight time is 15537: 0 1 hour, of which 1 1203: 25 hours for mechanics and 4334: 36 hours for pilots.

Type of aircraft flying: TB-20( 130 hours), Cheyenne (36 hours).

Current model: Boeing 737-300 flying 4 158: 36 hours (88 hours solo).

1996 65438+passed the technical inspection on February 25th.

Observer: Xiao Rong, male, born in July, 1948, with a total flight time of 5 179: 53 hours. He only had 123: 43 hours of simulator training on Boeing 737-300. Last technical inspection time:1April 199718th.

(2) Identity of the holder

Lin, the driving license is valid until 1997 1 1 month, and the medical certificate is valid until 1997 1 month;

Kong Dexin, the driver's license is valid until July 1997, and the medical certificate is valid until June1997+00;

Xiao Rong, the driver's license is valid until April 1998, and the medical certificate is valid until September1997;

(3) Good health

Crew members 1997 all qualified to fly. Before the flight, all the crew members had a pre-attendance physical examination, and no alcoholic drinks or drugs were found in the crew 8 hours before the flight. Through the analysis of cabin recording and understanding from the flight attendants of the same crew, it is found that there is no abnormality in the body of the crew during the flight, and the aviation disability of the crew is ruled out.

4. Meteorological and communication navigation equipment support.

Weather forecast for Shenzhen terminal: from May 8 17: 00 to May 9, 02: 00, 170 degrees, wind force of 7m/s, visibility of 6000m, weak showers, cloudy sky 1500m, sometimes wind force15m/s.

16: 40 "Airport Alert" issued for dangerous weather;

Affected by the thunderstorm in front of the front, there will be a wide range of unstable weather in our area from tonight to tomorrow morning, and there will be thunderstorms and windy weather in this station for a short time. Please pay attention.

The revised weather forecast is issued at 16: 50:

170 degree wind force 7m/s, gust 15m/s, uncertain wind direction, visibility 1500m, strong thunderstorm, 1 ~ 2 cloud observation 240m, 5 ~ 7 cloud observation 300m, 3 ~ 4 cumulonimbus observation 900m.

18: 00 "Airport Alert" issued for dangerous weather:

Notify the airport site, air traffic control, airline dispatch and other units: there will be thunderstorm and windy weather in this field, please pay attention to the relevant units and inform the units about to take off.

2 1: 00 weather facts:

290-degree wind 7m/s, visibility 1500m, runway visual range in the direction of runway No.33 1400m, moderate showers, 1 ~ 2 cumulonimbus clouds 1200m, 5 ~ 7 cumulonimbus clouds 1200m.

2 1: 33 special weather report:

240 degree wind 7m/s, visibility 2000m, moderate showers, 1 ~ 2 low-volume clouds 2 10m, 3 ~ 4 cumulonimbus clouds 1200m, 5 ~ 7 cumulonimbus clouds 1200m, temperature 22℃, dew point 22.

By listening to the general memories of land and air, watching radar videos and consulting relevant materials, it was confirmed that all kinds of support equipment such as communication, navigation and radar were working normally at that time; The weather meets the airport opening standards.

5. Aircraft and engine conditions

(1) aircraft

Model: B737-300B

Manufacturer: Boeing Company, USA

Registration number: B-2925

Factory serial number: 27288

Factory date:1February 24, 994,1February 28, 994 to Shenzhen,1May 7, 997, flying 8457: 53 hours.

Airworthiness certificate number. :AC0783

Number code of nationality registration certificate. :NR0940

Radio license number: 95-477

(2) Engine

Model: CFM-56-3CI

Manufacturer: CFMI Company

Serial number: left 857792 right 857794

By May 7th 1997, the left flight is 8457: 53 hours, and the right flight is 8457: 53 hours.

3) Inspection of documents and materials

Airworthiness instruction: By May 7th, 1997, all airworthiness instructions have been completed.

Time controls: all time controls

They are all within the validity period, and there are no overdue parts.

Reserved items:1997 There were no reserved items and faults before the plane crash on May 8.

Scheduled inspection and maintenance of aircraft: 1 July 8, 1996 to 1 April 29, 1997. 2C inspection1times, 1A- 12A inspection1times have been completed, and there is no major failure or overhaul.

(4) Shipwreck inspection

Fuselage: Except the tail of the fuselage is relatively complete (there are friction marks at the bottom), everything else is damaged.

Wing: the left wing was completely burned except the wing tip, the right wing tip was defective, and the front and rear edges were burned.

Engine: The fuel filter and lubricating oil filter of the left engine are clean and normal, and most fan blades are broken or bent. The fuel filter of the right engine is missing, the lubricating oil filter is clean and normal, and most blades are bent. Two engines are scrapped.

Landing gear: left landing gear: two main wheels are in place, the inner wheel is broken and the outer wheel is intact.

Right landing gear: the two main wheels are intact, and the outer cylinder of the shock absorber strut is compressed to the end, hitting the root of the inner cylinder with impact marks.

Front landing gear: the retracting and retracting actuator rod is broken, the front wheel steering actuator rod is broken, the left wheel falls off, and the right tire bursts.

Through inspection and flight data decoding and analysis, the aircraft, engine and system were in airworthiness state before the crash. Fuel and lubricating oil are qualified.

6. Aircraft load and center of gravity

The maximum commercial payload of this flight is 14248kg. * * * 65 passengers (including 64 adults and infants 1 person), weighing 4616 kg; Carrying 58 pieces of luggage, weighing 750 kilograms; Loading 29 pieces of goods, weighing 554 kilograms; Load mail 13 pieces, 12kg. It carries 5932 kilograms. Compared with the maximum payload, the unloaded weight is 83 16kg.

According to the loading of this machine, the center of gravity of not refueling should be 8.5%-28%, which is actually 17%. The center of gravity of takeoff weight should be 7.5%-28%, which is actually 17.2%. The center of gravity is in the best position, which meets the requirements.

According to this, it is proved that the machine does not have the problems of service overload and load balance.

7. Illegal interference

(1) According to the on-site investigation and interviews with witnesses, it is confirmed that there was no fire alarm or fire before the plane landed, so the possibility of landing after the fire can be ruled out.

(2) All passengers, luggage and goods on this flight were inspected according to regulations, and no prohibited items were found, so the possibility of loading inflammable and explosive dangerous goods was ruled out.

(3) After the samples were tested, no explosive residue was found on the aircraft wreckage, and no traces formed after the explosion were found.

(4) It can be ruled out that some surviving aircrew and passengers illegally interfere with aircraft flight.

8. Eyewitness reports

(1) According to the crew who met the plane at the tarmac at that time, it rained heavily and densely when the plane landed from south to north. When the plane landed from north to south after going around, it was raining heavily. It was dark and the visibility was poor. The plane was high, fast and sinking fast.

(2) According to the pilot of Shenzhen Airlines Flight 822, which landed three minutes ago, there is a "red zone" (thunderstorm zone) from Pingzhou to Shilong, with a width of 10 ~ 20 nautical miles.

According to the crew of Air China 1305, which landed five minutes after the first grounding, it was seen from the radar that there was a thunderstorm at the southern end of the airport, and it encountered heavy rain after cutting into the blind landing. The runway was seen from 800 feet of clouds, and it rained heavily. Because of the accumulated water on the runway, the landing lights didn't work, so we couldn't see the ground clearly, so we had to rely on the approach of the runway lights to control the plane.

(3) The flight attendants of the 2925 crew reported that when the flight was grounded for the first time, the seats of three flight attendants sitting at the back door were damaged, the luggage racks in the middle of the plane 17 and 18 were arched, the plane floor cracked and bulged, the windows were deformed, some of the top plates fell off, and there was a burning smell in the cabin, resulting in instantaneous power failure and some items in the luggage racks at the back of the cabin fell off.

cause analysis

(1) During the pentagonal approach, the attitude, track and glide slope of No.2925 aircraft remained normal before the altitude was determined, but the speed was too high (142.5 knots, the normal speed was 136 knots). The crew reported seeing the entrance lights and then reported seeing the runway. After determining the altitude, because the plane was flying in heavy rain, the crew decided to "turn on the light later" and used a rainproof agent.

Due to the heavy rain at night, the visibility is poor, the runway is flooded, the lighting effect is not good and the ground is not clear. In this case, the crew did not take the go-around measures decisively, violated the regulations, continued to approach and descend the altitude, lost the initiative and delayed the opportunity, which was the main reason for the abnormal landing and the ultimate cause of the accident.

(2) When the aircraft approached the platform with an altitude of 1 70ft, a warning of "glide slope low" appeared in the cockpit (point-1.38), and then the crew corrected the aircraft to return to the normal glide slope without lowering the throttle, thinking that "no matter how high the speed is", and increased the N 1 from 60% to.

After entering the runway at a height of 50 feet, the crew did not take back the tie rod in time to establish a normal landing attitude because they could not see the ground clearly, resulting in the plane grounding at the speed of 153.5 nautical miles/hour, and the front wheels and main wheels were in a horizontal attitude (the stopping angle of Boeing 737 was -0.79 to-1 degree, according to the recorded and decoded data, the attitude of the plane when it was grounded.

Two or three seconds before the plane landed, the cabin voice recorded "Steady point (steering column)!" "Hey!" Urgent publicity shows that we have just seen the road, but it is too late. It is too late to see the road clearly and not maintain the correct grounding posture, which is the direct cause of the plane's heavy landing and jumping.

(3) After the plane parachuted for the first time, the altitude was 5 feet, and the grounding vertical overload 1.9G crew did not make up their minds to turn off the throttle. The number of revolutions of N 1 increases or decreases irregularly, and it also has the function of pushing rod. Due to operational errors, the plane jumped twice in a row. The second jump is 7 feet, the grounding vertical overload is 2.54 g, and the third jump is 13 feet. Three consecutive jumps and overloading caused serious damage to the aircraft structure.

(4) After the third parachute jump, due to the heavy rain at high altitude and at night, the crew made a detour without knowing the damage procedure of the aircraft.

Due to the damage of the control system, when going around, the plane left the ground at a speed of 183 knots and a small elevation angle of 2 degrees (after the plane left the ground, the crew felt that the steering stick was "light" and the stick was "lighter"). After the plane was seriously damaged, the crew bypassed, laying a hidden danger for the second landing.

(5) After go-around, "main warning" and various warnings (hydraulic system, landing gear and flaps, etc. ) appears in the cockpit. After the damaged plane circled twice in the air, the crew decided to land in the opposite direction from north to south. Because the heavy rain has not stopped, the aircraft control system has failed (the change of steering rod obviously does not match the elevator deflection angle, the pull rod is large, and the elevator deflection angle is small). Although the crew pulled the stick to the end before landing, it failed to change the attitude of the plane flying at a large angle. Finally, the plane is still at a downward angle of 7.56 degrees, with a speed of 227.5 nautical miles per hour and a descending speed of 4 1 foot per second.

Accident conclusion

The plane encountered heavy rain in the final approach, and the crew descended blindly in violation of the rules without seeing the road clearly; Due to the inaccurate judgment of altitude, the plane did not maintain the correct landing attitude, which led to the heavy landing jump, and the pilot's manipulation error was the direct cause of this major accident. After the go-around, due to the serious damage to the aircraft, some control systems failed, and the crew could not control the landing attitude of the aircraft, so that the aircraft hit the ground at high speed when landing for the second time, resulting in the disintegration and crash of the aircraft. This is a major accident caused by human factors.

After listening to the recording, I feel that the crew members are very calm. During the whole process, except for the last cry of the co-pilot, all the conversations were orderly and there was no panic. Even when they informed the ground to prepare fire engines and ambulances, their voices were normal. Maybe they didn't realize that the first landing had caused irreparable disaster, and the ground didn't react much, maybe because the crew didn't report the first landing in detail. There was not much communication in the whole incident, and it didn't even seem to be a serious incident. In the case of damage to the health, other airports with good weather must be considered.