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Safety Recommendation Details

Safety Recommendation A-90-172
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: CREATE THE MECHANISM TO SUPPORT A HISTORICAL DATA BASE OF WORLDWIDE ENGINE ROTARY PART FAILURES TO FACILITATE DESIGN ASSESSMENTS AND COMPARATIVE SAFETY ANALYSIS DURING CERTIFICATION REVIEWS AND OTHER FAA RESEARCH.
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​
Report #: AAR-90-06
Accident Date: 7/19/1989
Issue Date: 12/14/1990
Date Closed: 12/8/1998
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 12/8/1998
Response: THE BOARD CLASSIFIED THIS RECOMMENDATION AS "OPEN--ACCEPTABLE RESPONSE" PENDING CONFIRMATION FROM THE FAA THAT IT WOULD MAINTAIN THE UNCONTAINED TURBINE ENGINE DEBRIS CHARACTERIZATION & MITIGATION DATABASE. THE FAA CONFIRMED THAT WOULD PRESERVE & RETAIN THE OVERALL DATABASE FOR UNCONTAINED ENGINE FAILURES GENERATED UNDER THE AIRCRAFT CATASTROPHIC FAILURE PREVENTION PROGRAM & THAT THE DATA WOULD BE AVAILABLE FOR FUTURE DESIGN ASSESSMENTS, SAFETY ANALYSES, & RESEARCH. BECAUSE THIS CONFIRMATION MEETS THE INTENT OF A-90-172, IT IS CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 9/10/1998
Response: (Letter Mail Controlled 9/14/98 3:44:04 PM MC# 981134) ON 6/24/98, THE BOARD CLASSIFIED THIS RECOMMENDATION AS "OPEN ACCEPTABLE" ACTION PENDING CONFIRMATION FROM THE FAA THAT IT WOULD MAINTAIN THE UNCONTAINED TURBINE ENGINE DEBRIS CHARACTERIZATION & MITIGATION DATA BASE. THIS LETTER CONFIRMS THAT THE FAA WILL PRESERVE & RETAIN THE OVERALL DATA BASE FOR UNCONTAINED ENGINE FAILURES GENERATED UNDER THE AIRCRAFT CATASTROPHIC FAILURE PREVENTION PROGRAM. THE DATA WILL BE AVAILABLE FOR FUTURE DESIGN ASSESSMENTS, SAFETY ANALYSES, & RESEARCH. I CONSIDER THE FAA'S ACTION TO BE COMPLETED IN RESPONSE TO THIS RECOMMENDATION.

From: NTSB
To: FAA
Date: 6/24/1998
Response: THE BOARD IS AWARE THAT THE FAA'S AIRPORT & AIRCRAFT SAFETY RESEARCH & DEVELOPMENT DIVISION OF THE WILLIAM J. HUGHES TECHNICAL CENTER IN ATLANTIC CITY, NEW JERSEY, AS PART OF THE AIRCRAFT CATASTROPHIC FAILURE PREVENTION PROGRAM, HAS FUNDED UNTIL 2001 AN UNCONTAINED TURBINE ENGINE DEBRIS CHARACTERIZATION & MITIGATION PROGRAM. AS A RESULT OF THIS PROGRAM, THE FAA INTENDS TO REVISE AC 20-128A, "DESIGN CONSIDERATIONS FOR MINIMIZING HAZARDS CAUSED BY UNCONTAINED TURBINE ENGINE & AUXILIARY POWER UNIT ROTOR FAILURE." SAFETY BOARD STAFF HAS PARTICIPATED IN SOME OF THE UNCONTAINED TURBINE ENGINE DEBRIS CHARACTERIZATION & MITIGATION WORKSHOP & NOTES THAT WITH THE COOPERATION OF INDUSTRY, THIS SIGNIFICANT PROGRAM HAS COMPILED EXTENSIVE ENGINEERING DATA INTO A COMPREHENSIVE DATA BASE ON ROTOR BURST DYNAMICS, DEBRIS TRAJECTORIES, CONTAINMENT SHIELD, & ACTUAL IN-SERVICE UNCONTAINED ENGINE FAILURE EVENTS. CONSEQUENTLY, THE BOARD BELIEVES THAT THE PRESERVATION OF THIS DATABASE WOULD MEET THE INTENT OF THIS RECOMMENDATION & SHOULD BE CONSIDERED ESSENTIAL FOR FUTURE DESIGN ASSESSMENTS & COMPARATIVE SAFETY ANALYSES & OTHER FAA RESEARCH. PENDING CONFIRMATION THAT THE FAA WILL MAINTAIN THE UNCONTAINED TURBINE ENGINE DEBRIS CHARACTERIZATION & MITIGATION DATABASE, THE BOARD CLASSIFIES A-90-172 "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 1/29/1998
Response: (Letter Mail Controlled 2/9/98 2:14:05 PM MC# 980138) IN JANUARY 1996, FAA TOLD THE BOARD THAT IT WOULD CREATE THE AIR TECHNICAL LIBRARY AUTOMATED SYSTEM TO PROVIDE EASY ACCESS TO SEVERAL RELATED DATA BASES & PROVIDE FAA PERSONNEL WITH A CENTRAL REPOSITOROY OF INFO TO FACILITATE DECISIONMAKING IN CERTIFICATION. HOWEVER, THE FAA NOW STATES THAT THIS CAPABILITY CURRENTLY EXISTS THROUGH THE NATIONAL AVIATON SAFETY DATA ANALYSIS CENTER (NASDAC), & AS A RESULT, THE FAA DOES NOT PLAN TO CONTINUE CREATING A SEPARATE DATA BASE. THE NASDAC INTEGRATES VARIOUS DATABASES & HAS SPECIALIZED SEARCH CAPABILITY ALLOWING COMPREHENSIVE RETRIEVAL OF SPECIFIC CATEGORIES OF EVENTS SUCH AS DISK UNCONTAINMENTS. UNCONTAINED ENGINE FAILURE DATA ARE INCLUDED IN THE NASDAC. THE NASDAC IS AVAILABLE TO FAA CERTIFICATION OFFICES & PRIVATE ENTITIES, & THE INFO OBTAINED THROUGH NASDAC CAN BE USED FOR MANY PURPOSES, INCLUDING COMPARATIVE SAFEY ANALYSIS & TREND ANALYSIS & EXPOSURE DATA. THE FAA IS ALSO CONTINUING ITS EFFORT TO PUBLISH AN ADVISORY CIRCULAR (AC) ENTITLED "CONTINUED AIRWORTHINESS ASSESSMENTS OF TURBINE ENGINES, PROPELLERS & AUXILIARY POWER UNITS," FOR USE IN CONDUCTING THE TYPE DESIGN ASSESSMENTS & COMPARATIVE SAFETY ANALYSIS DURING CERTIFICATION. THE FAA STATES THAT THE AC WILL ADDRESS BOTH TRANSPORT AIRCRAFT & ENGINE INSTALLATIONS & WILL PROVIDE HARMONIZATION FOR GOBAL CONTINUED AIRWORTHINESS STRATEGIES. IT IS ANTICIPATED THAT THE AC WILL BE PUBLISHED FOR COMMENT IN MID-1998. THE AC WILL PROVIDE GUIDANCE & ACCEPTABLE METHODS, BUT NOT THE ONLY METHODS, THAT MAY BE USED TO IDENTIFY, PRIORITIZE, & RESOLVE AIRWORTHINESS CONCERNS OCCURRING ON AIRCRAFT TURBINE ENGINES, PROPELLERS, & AUXILIARY POWER UNITS FOR USE ON CERTIFIED AIRCRAFT. IF A CERTIFICATE HOLDER ELECTS TO FOLLOW AN ALTERNATE METHOD, APPROVAL OF THAT METHOD MUST FIRST BE OBTAINED FROM THE FAA.

From: NTSB
To: FAA
Date: 4/22/1996
Response: THE FAA HAS PUBLISHED DRAFT ADVISORY CIRCULAR (AC) 39.XX, "CONTINUED AIRWORTHINESS ASSESSMENTS OF TURBINE ENGINES, PROPELLERS & APUS" FOR COMMENT. FURTHERMORE, THE FAA HAS DEVELOPED THE AIR TECHNICAL LIBRARY AUTOMATED SYSTEM (ATLAS). BOTH EFFORTS MEET THE INTENT OF A-90-172. PENDING FINAL PUBLICATION OF THE DRAFT AC & THE IMPLEMENTATION OF ATLAS, THE BOARD CLASSIFIES A-90-172 "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 1/26/1996
Response: THE FAA HAS PUBLISHED DRAFT ADVISORY CIRCULAR (AC) 39.XX, CONTINUE AIRWORTHINESS ASSESSMENTS, OF TURBINE ENGINES, PROPELLERS, & APUS, FOR COMMENTS. THE PROCESS OUTLINED IN THIS AC IS USEFUL IN CONDUCTING THE TYPES OF DESIGN ASSESSMENTS & COMPARATIVE SAFETY ANALYSIS IMPLIED IN THIS RECOMMENDATION. THIS PROCESS SHOULD FACILITATE EARLY IDENTIFICATION OF POTENTIAL SAFETY ISSUES OCCURRING ON TURBINE ENGINES, PROPELLERS, & AUXILIARY POWER UNITS. EARLY IDENTIFICATION OF THESE SAFETY ISSUES CAN BETTER ASSIST THE FAA IN DIRECTING THE DEVELOPMENT OF SPECIFIC DETAILED DATA THAT ARE NEEDED TO ASSESS & MITIGATE COMPLEX SAFETY ISSUES. I BELIEVE THE METHODS THAT ARE PRESENTED IN THE DRAFT AC FACILITATE THE UNDERSTANDING OF SAFETY-RELATED PROBLEMS & SUGGEST A CONSISTENT & MEASURED RESPONSE TO IDENTIFIED SAFETY PROBLEMS.

From: NTSB
To: FAA
Date: 11/30/1993
Response: THE BOARD NOTES THAT THE FAA HAS REQUESTED THAT THE SOCIETY OF AUTOMOTIVE ENGINEERS ESTABLISH A STANDING COMMITTEE OF INDUSTRY SAFETY EXPERTS TO REVIEW TURBINE ENGINE NONCONTAINMENT EVENTS. THE FAA BELIEVES THAT THE FORMATION OF THIS COMMITTEE WILL PROVIDE A COMPLETE, CURRENT, AND CENTRAL REPOSITORY OF TURBINE ENGINE NONCONTAINMENT DATA. BASED ON THIS INFORMATION, AND PENDING THE FORMATION OF THE COMMITTEE, THE BOARD CLASSIFIES RECOMMENDATION A-90-172 "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 6/30/1993
Response: THE FAA HAS REVIEWED ITS POSITION IN RESPONSE TO THIS RECOMMENDATION AND HAS DECIDED TO REQUEST THAT THE SOCIETY OF AUTOMOTIVE ENGINEERS ESTABLISH A STANDING COMMITTEE OF INDUSTRY SAFETY EXPERTS TO REVIEW TURBINE ENGINE NONCONTAINMENT EVENTS. I BELIEVE THAT THE FORMATION OF THIS COMMITTEE WILL PROVIDE A COMPLETE, CURRENT, AND CENTRAL REPOSITORY OF TURBINE ENGINE NONCONTAINMENT DATA.

From: NTSB
To: FAA
Date: 10/9/1991
Response: Safety Recommendation A-90-172 states that the FAA should create the mechanism to support a historical data base of worldwide engine rotary part failures to facilitate design assessments and comparative safety analysis during certification reviews and other FAA research. The Safety Board notes that the FAA believes a historical data base of rotating part failures and other critical parts already exists at each of the engine manufacturers. The Safety Board also notes that the FAA monitors this data, conducts safety assessments of each significant event, and conducts historical reviews during certification of new engine models. Therefore, the FAA plans no action on this safety recommendation. During this investigation the Safety Board discovered several sources of information concerning noncontainment events, in addition to the NTSB Special Study, "Turbine Engine Rotor Disk Failures, NTSB-AAS-74-4," such as FAA sponsored, industry -published SAE Report AIR 1537 and SAE Report AIR 4003; engine manufacturers’ and operators’ data; and the Annual Statistical Report of Aircraft Gas Turbine Engine Rotor Failures in U.S. Commercial Aviation derived from data reported through the Service Difficulty Report system and produced by the FAA Technical Center. The intent of this recommendation is for the FAA to establish a central repository or reporting and collecting program for acquiring and recording all such data, which is currently highly decentralized. The cumulative data could then be used to facilitate design assessments and comparative safety analysis during certification reviews and other FAA research. The Safety Board believes that the necessity for a centralized data storage point was implicit in our letter of recommendation and that the FAA should reconsider its position on Safety Recommendation A-90-172, which is classified as OPEN—UNACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 3/8/1991
Response: From James B. Busey, Administrator: Historical data bases of rotating part failures and other critical parts already exist at each of the engine manufacturer s. The FAA monitors those data and conducts safety assessments of each significant event and conducts historical reviews during certification of new engine models. As a result o action on this existing historical data bases, the FAA plans no action on this safety recommendation.