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Safety Recommendation Details

Safety Recommendation A-93-138
Details
Synopsis: ON MARCH 31, 1993, THE NO.2 ENGINE AND ENGINE PYLON SEPARATED FROM JAPAN AIRLINES, INC., FLIGHT 46E, A BOEING 747-121, THAT HAD BEEN WET-LEASED FROM EVERGREEN INTERNATIONAL AIRLINES, INC., SHORTLY AFTER DEPARTURE FROM ANCHORAGE INTERNATIONAL AIRPORT, ANCHORAGE, ALASKA. THE ACCIDENT OCCURRED ABOUT 1234 ALASKA STANDARD TIME. THE FLIGHT WAS A SCHEDULED CARGO FLIGHT FROM ANCHORAGE TO CHICAGO-O'HARE INTERNATIONAL AIRPORT, CHICAGO, ILLINOIS. ON BOARD THE AIRPLANE WERE THE FLIGHTCREW, CONSISTING OF THE CAPTAIN, THE FIRST OFFICER, AND THE SECOND OFFICER, AND TWO NONREVENUE COMPANY EMPLOYEES. THE AIRPLANE WAS SUBSTANTIALLY DAMAGED DURING THE SEPARATION OF THE ENGINE. NO ONE ON BOARD THE AIRPLANE OR ON THE GROUND WAS INJURED.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: REQUIRE THE BOEING-PROPOSED B-747 ENGINE PYLON STRUCTURAL MODIFICATION PROGRAM TO INCLUDE INCREASING THE LATERAL LOAD CAPABILITY OF THE PYLON STRUCTURE.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: ANCHORAGE, AK, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA93MA033
Accident Reports: In-Flight Engine Separation Japan Airlines, Inc., Flight 46E Boeing 747-121, N473EV
Report #: AAR-93-06
Accident Date: 3/31/1993
Issue Date: 11/15/1993
Date Closed: 10/17/1995
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 10/17/1995
Response: THE BOARD HAS REVIEWED AIRWORTHINESS DIRECTIVES 95-10-16, 95-13-05, 95-13-06, & 95-13-07, WHICH REQUIRE MODIFICATION OF THE ENGINE PYLON & WING STRUCTURE ON CERTAIN BOEING MODEL 747S ADDITIONAL INSPECTIONS & CHECKS TO DETECT & CORRECT DISCREPANCIES IN THESE STRUCTURES. THE FAA'S ISSUANCE OF THESE ADS COMPLIES WITH THE INTENT OF A-95-138, WHICH IS THEREFORE CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 8/7/1995
Response: THE FAA HAS ISSUED AIRWORTHINESS DIRECTIVES 95-10-16, 95-13-05, 95-13--6, & 95-13-07. THESE AD'S ARE APPLICABLE TO CERTAIN BOEING MODEL 747 SERIES AIRPLANES & REQUIRE MODIFICATION OF THE NACELLE STRUT & WING STRUCTURE, INSPECTIONS & CHECKS TO DETECT DISCREPANCIES, & CORRECTION OF DISCREPANCIES. THESE AD'S IMPROVE THE STRENGTH, FAIL-SAFE CAPABILITY, & DURABILITY OF THE STRUT-TO-WING ATTACHMENT STRUCTURE. I BELIEVE THAT THE FAA HAS COMPLETELY ADDRESSED THIS SAFETY ISSUE, & I CONSIDER THE FAA'S ACTION TO BE COMPLETED ON THIS RECOMMENDATION.

From: NTSB
To: FAA
Date: 6/17/1994
Response: THE BOARD ALSO NOTES THAT THE FAA PLANS TO INCREASE THE LATERAL STRENGTH OF THE AFT MIDSPAR WEB BY CHANGING IT TO STEEL & BACKING IT UP WITH A STEEL STRAP IN THE MODIFIED STRUT. PENDING ADDITIONAL INFO ON THE PROGRESS OF THESE MODIFICATIONS, THE BOARD CLASSIFIES A-93-138 "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 2/24/1994
Response: THE FAA AGREES WITH THE INTENT OF THIS RECOMMENDATION & IS DISCUSSING THIS ISSUE WITH BOEING. AS PART OF THE BOEING-PROPOSED STRUCTURAL MODIFICATION PROGRAM, THE FAA HAS COMPLETELY REEVALUATED THE DESIGN, FATIGUE, & FAIL-SAFE LOADS OF THE BOEING MODEL 747 SERIES ENGINE PYLON. THE FAA PLANS TO MODIFY THE STRUCTURAL DESIGN OF THE 747 STRUT & ALSO INCREASE THE LATERAL STRENGTH OF THE AFT MID-SPAR WEB.