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Safety Recommendation Details

Safety Recommendation A-79-052
Details
Synopsis: DATA OBTAINED DURING THE INVESTIGATION OF SERVICE PROBLEMS OF ALL MODEL DC-10 AIRCRAFT INDICATE THAT STRUCTURAL DAMAGE IN THE FORM OF CRACKS AND BUCKLES MAY DEVELOP IN ENGINE PYLON SPAR WEBS WHENEVER AN ENGINE FAILS IN A CATASTROPHIC MANNER. FAILURES INVOLVING SIGNIFICANT IMBALANCE CONDITIONS AND SEVERE SIDE LOADS ARE ESPECIALLY SUSPECTED OF PRECIPITATING SUCH DAMAGE.
Recommendation: ISSUE A MAINTENANCE ALERT BULLETIN TO U.S. CERTIFICATED AIR CARRIERS, AND NOTIFY STATES THAT HAVE REGULATORY RESPONSIBILITIES OVER FOREIGN AIR CARRIERS OPERATING DC-10 AIRCRAFT, TO REQUIRE APPROPRIATE STRUCTURAL INSPECTIONS OF THE ENGINE PYLONS FOLLOWING ENGINE FAILURES INVOLVING SIGNIFICANT IMBALANCE CONDITIONS OR SEVERE SIDE LOADS. (URGENT)
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Aviation
Location: Chicago, IL, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA79AA017
Accident Reports: American Airlines, Inc., DC-10, N110AA
Report #: AAR-79-17
Accident Date: 5/25/1979
Issue Date: 6/22/1979
Date Closed: 3/25/1981
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Alternate Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 3/25/1981
Response: In response to this recommendation, the FAA transmitted the Board's recommendation, verbatim, to all foreign operators of DC-10 aircraft and to those foreign states having regulatory responsibilities over foreign air carriers. The substance of this recommendation is also fulfilled in McDonnell Douglas Airworthiness Directive 80- 11-05 r1, amendment 39-3780; further amended by amendment 39-3981, paragraph 9(j). These amendments became effective on May 27, 1980, and December 8, 1990, respectively. The status of safety recommendation A-79-52 is now classified as Closed--Acceptable Alternate Action.

From: NTSB
To: FAA
Date: 7/11/1979
Response: We are pleased to note that the FAA has transmitted the Board's recommendation, verbatim, to all foreign operators of DC-10 aircraft and to those foreign states having regulatory responsibilities over foreign air carriers. We also note that the FAA plans to incorporate the substance of our recommendation in actions relating to the return to service of U.S. - registered DC-10 aircraft. Pending the fulfillment of these actions, this recommendation is being maintained in an Open--Acceptable Action status. In response to your request for data which indicates that structural damage may develop in engine pylon spar webs whenever an engine fails in a catastrophic manner, the Board has identified three instances of damage in pylons which were subjected to stresses associated with engine failures. These instances involved: (1) a united air lines DC-10 (fuselage no. 198) on which the no. 3 engine vibrated for about one hour after it was shutdownon 1/20/79, (2) a union de transport aeriens DC-10 (fuselage no. 63) on which the no. 1 engine failed catastrophically on 9/14/77, and (3) a National Airlines DC-10 (fuselage no. 62) on which the no. 1 engine seized on 10/17/76. This information was provided to the FAA personnel who participated in the Safety Board's DC-10 pylon design review.

From: FAA
To: NTSB
Date: 6/22/1979
Response: FAA LTR: THE U.S. REGISTERED DC-10 AIRCRAFT ARE GROUNDED; HOWEVER, THE SUBSTANCE OF YOUR RECOMMENDATION WILL BE INCORPORATED AS APPROPRIATE IN ACTIONS RELATING TO RETURN TO SERVICE. WE HAVE TRANSMITTED YOUR RECOMMENDATION, VERBATIM, TO ALL FOREIGN OPERATORS OF DC-10 AIRCRAFT AND TO THOSE FOREIGN STATES HAVING REGULATORY RESPONSIBILITIES OVER FOREIGN AIR CARRIERS. COMMENT: IN RESPONSE TO THIS RECOMMENDATION, THE FAA TRANSMITTED THE SAFETY BOARD'S RECOMMENDATION, VERBATIM, TO ALL FOREIGN OPERATORS OF DC-10 AIRCRAFT AND TO THOSE FOREIGN STATES HAVING REGULATORY RESPONSIBILITIES OVER FOREIGN AIR CARRIERS. THE SUBSTANCE OF THIS RECOMMENDATION IS ALSO FULFILLED IN MCDONNELL DOUGLAS AIRWORTHINESS DIRECTIVE, 80-11-05 R1, AMENDMENT 39-3780; FURTHER AMENDED BY AMENDMENT 39-3981, PARAGRAPH 9(J). THESE AMENDMENTS BECAME EFFECTIVE ON MAY 27, 1980, AND DECEMBER 8, 1980, RESPECTIVELY.