Air Crash Investigations - Inadvertent In-Flight Slat Deployment - The Near Crash of China Eastern Airlines Flight 583

By Dirk Barreveld

On April 6, 1993, a China Eastern Airlines McDonnell Douglas MD-11, flight 583, on its way from Beijing, China, to Los Angeles, California, had an inadvertent deployment of the leading edge wing slats while in cruise flight, not far from Shemya, Alaska. The autopilot disconnected, and the captain was manually controlling the airplane when it progressed through several violent pitch oscillations and lost 5,000 feet of altitude. Two passengers were fatally injured, and 149 passengers and 7 crewmembers received various injuries. The airplane did not receive external structural damage, but the passenger cabin was substantially damaged. The National Transportation Safety Board determined that the probable cause of this accident was the inadequate design of the flap/slat actuation handle by the Douglas Aircraft Company that allowed the handle to be easily and inadvertently dislodged from the UP/RET position, thereby causing extension of the leading edge slats during cruise flight.

• Language: English
• Publisher: Lulu.com
• Release date: Nov 26, 2015
• ISBN: 9781329716544

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Air Crash Investigations - Inadvertent In-Flight Slat Deployment - The Near Crash of China Eastern Airlines Flight 583

AIR CRASH INVESTIGATION

Over the last decades flying has become an everyday event, there is nothing special about it anymore. Safety has increased tremendously, but unfortunately accidents still happen. Every accident is a source for improvement. It is therefore essential that the precise cause or probable cause of accidents is as widely known as possible. It can not only take away fear for flying but it can also make passengers aware of unusual things during a flight and so play a role in preventing accidents. Air Crash Investigation Reports are published by official government entities and can in principle usually be down loaded from the websites of these entities. It is however not always easy, certainly not by foreign countries, to locate the report someone is looking for. Often the reports are accompanied by numerous extensive and very technical specifications and appendices and therefore not easy readable. In this series we have streamlined the reports of a number of important accidents in aviation without compromising in any way the content of the reports in order to make the issue at stake more easily accessible for a wider public.

An e-Book is different from a printed book. Especially tables, graphs, maps, foot and end notes and images are sometimes too complicated to be reproduced properly in an e-Book. For those who are interested in the full details of the story we refer to the printed edition of this publication.

Dirk J. Barreveld, editor.

INADVERTENT IN-FLIGHT SLAT DEPLOYMENT: The Near Crash of China Eastern Airlines Flight 583

Copyright Page

INADVERTENT IN-FLIGHT SLAT DEPLOYMENT CHINA EASTERN AIRLINES FLIGHT 583, APRIL 6, 1993

Accident Report NTSB/AAR-93/07, concerning inadvertent in-flight slat deployment of a China Eastern Airlines McDonnell Douglas MD-11, B-2171, Flight 583, 950 nautical miles south of Shemya, Alaska

All Rights Reserved © 2015 Sagip Kabayan

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No part of this book may be reproduced or transmitted in any form or by any means, graphic, electronic, or mechanical, including photocopying, recording, taping, or by any information storage retrieval system, without the permission in writing from the publisher.

Foundation Sagip Kabayan

ISBN: 978-1-329-71654-4

Table of Content

INADVERTENT IN-FLIGHT SLAT DEPLOYMENT: The Near Crash of China Eastern Airlines Flight 583

Title Page

Copyright Page

Table of Contents

Synopsis

Executive Summary

Chapter 1: FACTUAL INFORMATION

Chapter 2: TESTS AND RESEARCH

Chapter 3: ADDITIONAL INFORMATION

Chapter 4: ANALYSIS

Chapter 5: CONCLUSIONS

Chapter 6: RECOMMENDATIONS

Appendix A: Investigation and Hearing

Appendix B: RESPONSE OF CIVIL AVIATION ADMINISTRATION OF CHINA TO SAFETY BOARD’S DRAFT OF AVIATION ACCIDENT REPORT

Endnotes

Air Crash Investigations

EXECUTIVE SUMMARY

On April 6, 1993, at 0110 Hawaiian Standard Time, China Eastern Airlines flight 583, a McDonnell Douglas MD-11, Chinese registration B-2171, a scheduled international passenger flight from Beijing, China, to Los Angeles, California, with an intermediate stop in Shanghai, China, had an inadvertent deployment of the leading edge wing slats while in cruise flight, approximately 950 nautical miles south of Shemya, Alaska. The autopilot disconnected, and the captain was manually controlling the airplane when it progressed through several violent pitch oscillations and lost 5,000 feet of altitude. The captain regained stabilized flight, declared an emergency because of passenger injuries, and diverted to the U. S. Air Force Base, Shemya, Alaska. Of the 235 passengers and 20 crewmembers aboard the airplane, 2 passengers were fatally injured, and 149 passengers and 7 crewmembers received various injuries. The airplane did not receive external structural damage, but the passenger cabin was substantially damaged.

The National Transportation Safety Board determines that the probable cause of this accident was the inadequate design of the flap/slat actuation handle by the Douglas Aircraft Company that allowed the handle to be easily and inadvertently dislodged from the UP/RET position, thereby causing extension of the leading edge slats during cruise flight. The captain's attempt to recover from the slat extension, given the reduced longitudinal stability and the associated light control force characteristics of the MD-11 in cruise flight, led to several violent pitch oscillations.

Contributing to the violence of the pitch oscillations was the lack of specific MD-11 pilot training in recovery from high altitude upsets, and the influence of the stall warning system on the captain's control responses. Contributing to the severity of the injuries was the lack of seat restraint usage by the occupants.

The safety issues in this report focused on the inadequate design of the flap/slat actuation handle on the MD-11 airplane, the inadvertent extension of the leading edge wing slats, the longitudinal stability of the MD-11 during the pitch upset, and the pilot-induced oscillations that can occur during the recovery. Also discussed is the premature deterioration of the seat cushion fire-blocking material and the inability of the material to provide the required seat cushion fire protection on transport-category airplanes.

Safety recommendations concerning, these issues were addressed to the Federal Aviation Administration.

CHAPTER 1: FACTUAL INFORMATION

History of Flight

On April 6, 1993, at 01 10 Hawaiian Standard Time (HST), China Eastern Airlines flight 583 (CES583), a McDonnell Douglas MD-11, Chinese registration B-2171, a scheduled international passenger flight from Beijing, China, to Los Angeles, California, (LAX) with an intermediate stop in Shanghai, China, had an inadvertent deployment of the leading edge wing slats while in cruise flight, approximately 950 nautical miles south of Shemya, Alaska. The autopilot disconnected, and the captain was manually controlling the airplane when it progressed through several violent pitch oscillations and lost 5,000 feet of altitude. The captain regained stabilized flight, declared an emergency because of passenger injuries, and diverted to the U.S. Air Force Base, Shemya, Alaska. Of the 235 passengers and 20 crewmembers aboard the airplane, 2 passengers were fatally injured, and 149 passengers and 7 crewmembers received various injuries. The airplane received no external structural damage, but the passenger cabin interior was extensively damaged.

The flight-crew reported that the operation of the airplane from Beijing to its intermediate stop at Shanghai was normal. They also reported that the take-off, climb and initial en route segment of the flight from Shanghai to Los Angeles were normal.

The airplane had been airborne about 5 hours, and the flight attendants had cornp1eted the meal service and had dimmed the lights for a movie when the airplane began the violent pitch oscillations.

The captain involved in the accident stated in an interview with Safety Board investigators that he was one of four members of the oncoming relief flight-crew that had assumed flight responsibilities of the airplane approximately 20 minutes prior to the event. The captain further stated that he was the flying pilot but occupied the right seat at the time of the accident because he was providing instruction to the first officer in the left seat.

At the time of the accident, the airplane was in cruise flight at 33,000 feet (FL330), above the clouds, at an indicated airspeed of approximately 298 knots (Mach 0.82) with the No. 1 autopilot engaged. The captain stated that they had not experienced any unusual weather phenomenon until approximately 15 minutes prior to the event. At that time, the