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Safety Recommendation Details

Safety Recommendation A-90-167
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: Intensify research in the nondestructive inspection field to identify emerging technologies that can serve to simplify automate, or otherwise improve the reliability of the inspection process. Such research should encourage the development and implementation of redundant ("second set of eyes") inspection oversight for critical part inspections, such as for engine rotating components.
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: 4/2/1992
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Oversight

Safety Recommendation History
From: NTSB
To: FAA
Date: 4/2/1992
Response: The Safety Board notes that the FAA's titanium rotating components review team report dated December 14, 1990, identifies several recommendations regarding manufacturing process control, manufacturing inspection, in-service inspection, design procedures, research and development, and FAA policy and guidance. We also note that several FAA initiatives encompass the nondestructive evaluation aspects of rotating components, and under the aging aircraft program, an effort is already underway to assess emerging nondestructive inspection procedures, equipment, techniques, and training facilities for potential application in the commercial fleet. Based on these and other ongoing actions by the FAA, safety recommendation A-90-167 is classified as CLOSED—ACCEPTABLE ACTION.

From: NTSB
To: FAA
Date: 10/9/1991
Response: Thank you for the Federal Aviation Administration (FAA) response of March 8, 1991, to the National Transportation Safety Board's Safety Recommendations A-90-167 through -175. Safety Recommendation A-90-167 states that the FAA should intensify research in the nondestructive inspection field to improve the reliability of the inspection process. The Safety Board notes that the FAA has identified the U.S. Air Force as an excellent source of information on nondestructive inspection technology and automated equipment to improve the reliability of the inspection process. The Safety Board is pleased to note that the FAA agrees with the Board that implementation of redundant ("second set of eyes") inspection oversight is essential to improving the aging aircraft program. Pending further information, Safety Recommendation A-90-167 is classified as OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 9/16/1991
Response: The FAA utilizes redundant inspections performed by different inspectors to improve the reliability of the inspection process in specific cases where low reliability was realized. In the specific case of the general electric cf6-6 stage I fan disk, in addition to the fluorescent penetrant inspection, an enhanced surface inspection of the disk bore has been added to the engine shop manual. On may 9, 1991, the FAA's engine and propeller directorate sponsored a titanium review conference. During this conference the titanium rotating components review team report dated December 14, 1990, was released to the industry and public participants. This report identifies several recommendations regarding manufacturing process control, manufacturing inspection, in-service inspection, design procedures, research and development, and FAA policy and guidance. Additionally, several FAA initiatives such as those defined in the engine hazards study and the titanium rotating components review team report encompass the nde aspects of rotating components. Under the aging aircraft program, a task is already under way to assess emerging nondestructive inspection (NDI) procedures, equipment, techniques, and training facilities for potential application in the commercial fleet.

From: FAA
To: NTSB
Date: 3/8/1991
Response: James B. Busey, Administrator: The U.S. Air Force has conducted extensive research on critical engine component inspection techniques utilizing automated equipment. The Federal Aviation Administration (FAA) is aware of these nondestructive evaluation (NE) efforts and of the automated equipment that has been designed and implemented in the military inspection arena. Several issues must be addressed in considering the adaptation of these techniques and equipment into the commercial arena, such as modification of equipment to accept larger size components, complex geometries, and surface finishes. The FAA has and will continue to utilize redundant inspections performed by different inspectors to improve the reliability the inspection process in specific cases where low reliability was realized. In the specific case of the General Electric CF6-6 stage I fan disk, an enhanced surface inspection of the disk bore has been added to the engine shop manual, in addition to the fluorescent penetrant inspection. Several initiatives such as the Engine Hazards Study and the Titanium Rotating Component Review Team encompass the NDE aspects of rotating components. Under the aging aircraft program, a task is already underway to assess emerging nondestructive inspection procedures, equipment, techniques, and training facilities for potential application in the commercial fleet. Other NDE tasks are under consideration for incorporation into the aging aircraft program. I will keep the Board apprised of the FAA's progress on this safety recommendation.