At 7:57 on August 9, Shenzhen Airlines ZH9209 issued an emergency code of 7700 and then returned. Some media reported that prior to this, the airliner had experienced a sharp drop in altitude within two minutes, from 9297 meters to 3733 meters.

　　On the same day, senior captain Chen Jianguo told The Paper (www.thepaper.cn) that according to his understanding, the Shenzhen Airlines ZH9209 aircraft began to descend urgently at 7:52 and changed to level flight at 7:57. The plane dropped about 5,500 meters in 5 minutes, an average of about 1,100 meters per minute.

　　Chen Jianguo said that it is impossible for the plane to drop 6,000 meters in two minutes. If the plane drops nearly 3000 meters per minute, the plane will disintegrate at a speeding speed.

　　A relevant person in charge of Shenzhen Airlines told The Paper that, in response to the statement that the aircraft plunged 6 kilometers in two minutes, the altitude and time data of the aircraft plunged were inaccurate, "it is impossible to descend so fast."

　　The aforementioned person in charge also stated that the sudden drop of the flight involved is the operation of the crew in accordance with the process, and the specific data of the sudden drop is still unclear.

　　Some media reported that the flight involved was planned to fly from Shenzhen to Xi'an. About 25 minutes after taking off from Shenzhen Baoan Airport at 7:32 on the 9th, there was a sudden drop in altitude. Then the flight began to return, and the transponder code was also changed from 7700 to a normal code, indicating that the emergency situation of the aircraft has been controlled and the crew can control the aircraft to land normally.

　　The official Weibo of Shenzhen Airlines Co., Ltd.@深圳航空 announced at 11 o'clock on the 9th that at 09:13, Shenzhen Airlines Flight ZH9209 returned due to a mechanical failure, and the crew was properly handled. It has landed at Shenzhen Baoan International Airport safely. The crew and passengers are all After getting off the plane safely, Shenzhen Airlines will arrange other flights to transport passengers. The cause of the fault is still under further investigation.

　　It is understood that 7700 is the code for the passenger plane transponder, which will be sent to the outside when the passenger is in an emergency situation for special treatment by air traffic control personnel. The Shenzhen Airlines ZH9209 passenger aircraft is an Airbus A330 passenger aircraft, which is 2.3 years old.

　　The Paper, reporter Zhu Lei