Summary
On April 06, 1993, a Mcdonnell Douglas MD-11 (B2171) was involved in an accident near Shemya, AK. The accident resulted in 2 fatal injuries, 60 serious injuries, 96 minor injuries, with 97 people uninjured out of 255 aboard. The aircraft sustained minor damage.
The National Transportation Safety Board determined the probable cause of this accident to be: 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.
SEE NTSB BLUE COVER FACTUAL ACCIDENT REPORT - NTSB/AAR- 93/07
This accident is documented in NTSB report DCA93MA037. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft B2171.
Accident Details
Probable Cause and Findings
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.
Aircraft Information
Analysis
SEE NTSB BLUE COVER FACTUAL ACCIDENT REPORT - NTSB/AAR- 93/07
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# DCA93MA037