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Safety Recommendation Details

Safety Recommendation A-90-168
Details
Synopsis: ON JULY 19, 1989, AT 1516, A DC-10-10, N1819U, OPERATED BY UNITED AIRLINES (UAL) AS FLIGHT 232, EXPERIENCED A CATASTROPHIC FAILURE OF THE NO. 2 TAIL-MOUNTED ENGINE DURING CRUISE FLIGHT. THE SEPARATION, FRAGMENTATION AND FORCEFUL DISCHARGE OF STAGE 1 FAN ROTOR ASSEMBLY PARTS FROM THE NO. 2 ENGINE LED TO THE LOSS OF THE THREE HYDRAULIC SYSTEMS THAT POWERED THE AIRPLANE'S FLIGHT CONTROLS. THE FLIGHTCREW EXPERIENCED SEVERE DIFFICULTIES CONTROLLING THE AIRPLANE, WHICH SUBSEQUENTLY CRASHED DURING AN ATTEMPTED LANDING AT SIOUX GATEWAY AIRPORT, IOWA. THERE WERE 285 PASSENGERS AND 11 CREWMEMBERS ONBOARD. ONE FLIGHT ATTENDANT AND 110 PASSENGERS WERE FATALLY INJURED.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ENCOURAGE RESEARCH AND DEVELOPMENT OF BACKUP FLIGHT CONTROL SYSTEMS FOR NEWLY CERTIFICATED WIDE-BODY AIRPLANES THAT UTILIZE AN ALTERNATIVE SOURCE OF MOTIVE POWER SEPARATE FROM THAT SOURCE USED FOR THE CONVENTIONAL CONTROL SYSTEM.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: SIOUX CITY, IA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA89MA063
Accident Reports: United Airlines Flight 232 McDonnell Douglas DC-10-10‚Äč
Report #: AAR-90-06
Accident Date: 7/19/1989
Issue Date: 12/14/1990
Date Closed: 4/22/1996
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 4/22/1996
Response: THE FAA'S TRANSPORT AIRPLAN DIRECTORATE IS SPONSORING A RESEARCH & DEVELOPMENT PROGRAM TO EXPLORE PROTECTION OF FLIGHT CONTROLS ON TRANSPORT-CATEGORY AIRPLANES. FURTHERMORE, THE FAA'S CONTRACTS WITH PRINCETON UNIVERSITY & CROWN COMMUNICATIONS FOR FLIGHT CONTROL STUDIES SUPPORT THE INTENT OF THIS RECOMMENDATION. BASED ON THIS INFO, THE BOARD CLASSIFIES A-90-168 "CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 1/26/1996
Response: THE FAA TRANSPORT AIRPLANE DIRECTORATE IS SPONSORING A RESEARCH & DEVELOPMENT PROGRAM TO EXPLORE PROTECTION OF FLIGHT CONTROLS ON TRANSPORT CATEGORY AIRPLANES. THE RESEARCH IS LIMITED TO THE SURVIVABILITY OF NEW TECHNOLOGY SYSTEMS (AUTOMATIC & FLY-BY-WIRE) IN SCENARIOS WHERE THE POTENTIAL FOR SURVIVABILITY IS GREATEST. THERE IS SUFFICIENT SERVICE HISTORY ON CONVENTIONAL HYDROMECHANICAL & ELECTRICAL CONTROL SYSTEMS TO DEVELOP STANDARDS THAT WOULD ENSURE MAXIMUM SURVIVABILITY. ADDITIONAL RESEARCH ON CONVENTIONAL SYSTEMS WOULD UNDOUBTEDLY CONFIRM THAT BACKUP SYSTEMS ALONE WOULD NOT ENSURE SURVIVABILITY UNLESS THE BACKUP SYSTEMS WERE ALSO SEPARATED FROM THE SYSTEMS THEY FUNCTIONALLY DUPLICATE.

From: NTSB
To: FAA
Date: 11/30/1993
Response: THE BOARD NOTES THAT THE FAA'S TRANSPORT AIRPLANE DIRECTORATE IS SPONSORING A RESEARCH AND DEVELOPMENT PROGRAM TO EXPLORE PROTECTION OF THE FLIGHT CONTROL SYSTEMS ON TRANSPORT CATEGORY AIRPLANES THAT WILL BEGIN IN FISCAL YEAR 1995. ADDITIONALLY, THE SYSTEMS REVIEW TASK FORCE HAS COMPLETED ITS REPORT ON POSSIBLE DESIGN CONCEPTS THAT WILL PROVIDE ALTERNATIVE MEANS OF CONTROL OF FLIGHT CRITICAL FUNCTIONS IN THE EVENT OF TOTAL LOSS OF ALL (NORMAL) REDUNDANT SYSTEMS. BASED ON THIS INFORMATION, THE BOARD CLASSIFIES RECOMMENDATION A-90-168 "OPEN ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 6/30/1993
Response: THE FAA AGREES WITH THIS RECOMMENDATION. THE FAA'S TRANSPORT AIRPLANE DIRECTORATE IS SPONSORING A RESEARCH AND DEVELOPMENT PROGRAM TO EXPLORE PROTECTION OF THE FLIGHT CONTROL SYSTEM ON TRANSPORT CATGORY AIRPLANES. THE PROPOSED RESEARCH IS LIMITED TO NEW TECHNOLOGY SYSTEMS WHERE THE POTENTIAL FOR IMPROVED SURVIVABILITY IS THE GREATEST. IT IS ANTICIPATED THAT THIS PROGRAM WILL BEGIN IN FISCAL YEAR 1995. THE SYSTEMS REVIEW TASK FORCE, WHICH WAS FORMED TO DETERMINE POSSIBLE DESIGN CONCEPTS THAT WILL PROVIDE ALTERNATIVE MEANS OF CONTROL OF FLIGHT CRITICAL FUNCTIONS IN THE EVENT OF TOTAL LOSS OF ALL (NORMAL) REDUNDANT SYSTEMS WHICH PROVIDE THAT CONTROL REGARDLESS OF THE PROBABILITY OF SUCH LOSS, HAS COMPLETED ITS REPORT.

From: NTSB
To: FAA
Date: 10/9/1991
Response:

From: FAA
To: NTSB
Date: 3/8/1991
Response: