China Eastern Airlines Flight 583

China Eastern Airlines Flight 583
	B-2171, the aircraft involved in the accident, at Beijing Capital Airport in 1995, 2 years after the accident.
Accident
Date	April 6, 1993
Summary	In-flight upset due to accidental deployment of slats
Site	Near the Aleutian Islands ; 30°N 172°E / 30°N 172°E
Aircraft
Aircraft type	McDonnell-Douglas MD-11
Operator	China Eastern Airlines
IATA flight No.	MU583
ICAO flight No.	CES583
Call sign	CHINA EASTERN 583
Registration	B-2171
Flight origin	Beijing Capital International Airport, Beijing, China
Stopover	Hongqiao International Airport, Shanghai, China
Destination	Los Angeles International Airport, Los Angeles, United States
Occupants	255
Passengers	235
Crew	20
Fatalities	2
Injuries	156
Survivors	253

China Eastern Airlines Flight 583 was a commercial passenger flight from Shanghai, China, to Los Angeles, United States, operated by China Eastern Airlines.

Aircraft

The aircraft involved was a McDonnell Douglas MD-11, MSN 48495, registered as B-2171, that was built by McDonnell Douglas in 1991. It had logged approximately 4,810 airframe hours and 1,571 takeoff and landing cycles and was equipped with three Pratt & Whitney PW4460 engines.^[1]

Accident

On April 6, 1993, the McDonnell-Douglas MD-11 operating the service was cruising above the Pacific Ocean at Mach 0.84 when a crew member accidentally deployed the slats near the Aleutian Islands. The plane then encountered severe oscillations^[2] and made an emergency landing at Shemya Air Force Base in Shemya, Semichi Islands, Alaska.^[3]

The damage to the cabin of Flight 583

Of the 255 passengers and crew, 60 were hospitalized; two ultimately died.^[4] Of the cockpit crew, five received no injuries and three received serious injuries. Of the flight attendants, eight received no injuries and four received serious injuries. Of the surviving passengers, 84 received no injuries, 96 received minor injuries, and 53 received serious injuries.^[4] By April 24, 1993 all but three of the surviving passengers were discharged from the hospital.^[5]

Investigation

The National Transportation Safety Board report found that the handle used to actuate the leading edge flaps/slats was poorly designed, and the captain likely moved this handle unintentionally while performing an unrelated task. This unexpected slats deployment caused the nose to pitch up. The pilot returned the handle to the correct position and, in an effort to correct the plane's pitch, pushed the control column forward with enough force to trigger the autopilot to disengage, thus causing an abrupt nose-down elevator movement. The plane continued to oscillate between nose up and nose down pitch due to the pilot's overcorrection of the elevator inputs until they were able to stabilize the plane's attitude. The violent pitching movement caused injuries to the occupants. At the time of the accident, passengers were either not wearing seatbelts or had them loose, or were standing in the aisle, exacerbating the number and extent of injuries.

Other contributing factors included the lack of pilot training in high altitude upset recovery, the light control force characteristics at cruising altitude, and the influence of the stall warning system engaging and disengaging during the oscillations on the pilot's control inputs.^[4]