China Northwest Airlines

China Northwest Airlines

China Northwest Airlines Co., Ltd. was an airline based in the People's Republic of China. It started operations in 1989. In 2002, the airline, along with China Yunnan Airlines merged with China Eastern Airlines....

 Flight 2303 was a domestic flight from Xian to Guangzhou

Guangzhou

Guangzhou , known historically as Canton or Kwangchow, is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about north-northwest of Hong Kong, Guangzhou is a key national transportation hub and trading port...

, People's Republic of China

People's Republic of China

China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

. On June 6, 1994, this aircraft, a Tupolev Tu-154M, broke up in-flight and crashed as a result of an autopilot

Autopilot

An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...

 malfunction which caused violent shaking and overstressed the airframe.

Approximately eight minutes after takeoff (ten minutes in some reports), the control tower at Xianyang Airport lost contact with the plane and it crashed in a field 18 miles southeast of the airport. All 146 passengers and 14 crew died. As of 2011, it remains the deadliest airplane crash ever to occur in China.

Flawed maintenance of the aircraft is the probable cause of the sequence of events. The previous evening, the autopilot yaw-channel

Flight dynamics

Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...

 had been erroneously connected to the bank control, and the bank-channel

Banked turn

A banked turn is a turn or change of direction in which the vehicle banks or inclines, usually towards the inside of the turn. The bank angle is the angle at which the vehicle is inclined about its longitudinal axis with respect to its path....

 to the yaw controls

Aircraft flight control systems

A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...

. Additionally, this incorrect maintenance was not done in a properly approved facility.

Passengers

133 of the passengers were from Mainland China, 4 (including 2 children) were from Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, 3 were from Hong Kong

Hong Kong

Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

, 1 was from Taiwan, and 9 were from other countries.