The safety board is particularly concerned that because of the limitations of the current reporting system the FAA and key engineering and maintenance personnel at American Airlines were not aware that Continental Airlines had damaged two aft bulkhead flanges on two of its DC-10s until after the accident. In December 1978, after it discovered the first damaged bulkhead, Continental apparently conducted a cursory investigation and determined that the damage resulted from a maintenance error. A repair was designed for the bulkhead and was submitted to McDonnell Douglas for stress analysis approval. The repair was approved and performed, and the aircraft returned to service.

On January 5, 1979, Operational Occurrence Report No. 107901 was published by McDonnell Douglas. The publication contained descriptions of several DC-10 occurrences involving various aircraft systems, personnel injury, and the damage inflicted on the Continental Airlines DC-10. The report described the damage to the upper flange of the Continental aircraft and indicated that it occurred during maintenance procedures used at the time it was damaged. However, the way in which the damage was inflicted was not mentioned. The manufacturer had no authority to investigate air carrier maintenance practices and, therefore, accepted the carrier's evaluation of how the flange was damaged. Since the damage was inflicted during maintenance, 14 CFR 21.3 relieved McDonnell Douglas of any responsibility to report the mishap to the FAA. Although American Airlines was on the distribution list for Operational Occurrence Reports, testimony disclosed that the maintenance and engineering personnel responsible for the pylon maintenance were not aware of the report.

Continental Airlines discovered the damage to the second bulkhead in February 1979. Again the carrier evaluation indicated that the cause of the damage was related to personnel error, and that there was apparently no extensive effort to evaluate the enginepylon assembly removal and reinstallation procedures. The bulkhead was also repaired using the procedure previously approved by McDonnell Douglas.

The carrier did not report the repairs that were made to the two bulkheads to return them to service, and there was no regulatory requirement to do so. What constitutes a major repair may be subject to interpretation, but what is to be reported is not. The bulkheads were not altered; they were repaired. Even had the repairs been classified by the carrier as major, 14 CFR 121.707(b) only requires that a report be prepared and kept available for inspection by a representative of the FAA. Second, the regulation does not indicate that the contents of the required report include a description of the manner in which the damage was inflicted. The regulation and the evidence indicated that the purpose of the reports was to permit the FAA to evaluate the end-product to insure that the basic design of the repaired or altered part had not been changed.

The Mechanical Reliability Reporting criteria of 14 CFR 121.703 requires the certificate holder to report "the occurrence or detection of each failure, malfunction, or defect concerning. . .' and then lists 16 criteria to which these apply. The FAA and apparently the aviation industry have traditionally interpreted 121.703 to apply to only service-related problems, which would therefore exclude reporting-of the flange damage caused by maintenance. In view of this interpretation, the board concludes that there is a serious deficiency in the reporting requirements which should be corrected.

Therefore, the safety board concludes that neither the air carrier nor the manufacturer interpreted the regulation to require further investigation of the damages or to report the damage to the FAA. However, the safety board views the omission of such requirements as a serious deficiency in the regulations.

Wow. A real life soap opera!