Aviation Investigation Report A98H0003

2.8  Maintenance and Quality Assurance Aspects

During the investigation, the maintenance condition of the aircraft was assessed by reviewing the aircraft's maintenance records and SR Technics maintenance policies, procedures, and practices.

The records for the occurrence aircraft indicate that required maintenance had been completed, and that the aircraft was being maintained in a manner consistent with approved maintenance procedures and industry norms. Although several "bookkeeping" anomalies were found, the overall method of record-keeping was sound.

The condition of the SR 111 wreckage did not allow for a full determination of the pre-occurrence condition of the aircraft. Therefore, investigators inspected several MD-11s, including those in the Swissair fleet, and used the information from these inspections to help assess the potential ignition sources. During these inspections of the MD-11s, various discrepancies were noted in the installation and maintenance of the electrical system, including chafing on wires, incorrectly torqued terminal connections, and inconsistent wire routing. None were considered to affect the immediate safety of flight. Some of the discrepancies could be attributed to the manufacturer of the aircraft, and others to subsequent installations and ongoing maintenance.

The SR Technics quality assurance (QA) program satisfied regulatory requirements. It involved a multi-faceted approach that relied on training, trend analysis, reliability, and structured audits. The number and type of anomalies discovered during the investigation, which included a review of the findings of the various internal and external audits, suggest that while the QA program design was sound, its implementation did not sufficiently ensure that potential safety aspects were consistently identified and mitigated. (STI2-1)

The SR Technics maintenance organization exposition (MOE) required that all employees be trained to be personally responsible for the quality of their work; that is, the work was expected to be accomplished correctly, and a self-inspection was to be completed after each "work step." Whenever work was carried out where the consequences of a mistake in doing the work presented a risk to persons or material (as determined by a risk assessment team), a double inspection was called for. Supervisors were to ensure that the QA program was being followed, and were to inspect the quality of the work in their area of supervision. Individuals received general QA instructions and familiarization training on documentation, policies, and procedures, but did not receive (nor did the MOE make reference to) specific training on how to consistently implement the QA program. The primary task of those involved in the day-to-day QA activities was to maintain the aircraft. There are indications that they dealt with some of the various technical discrepancies and anomalies as reliability issues rather than potential safety deficiencies. Although regulatory requirements were met, some aspects of the QA program were not consistently implemented.

A post-occurrence SR Technics review of its own QA program determined that a weak link in its program was the reliance on individual judgment. This observation had not been made in any of their previous internal audit findings. Although judgment plays a role in any QA program, it appears that the SR Technics QA program was over-reliant on the ability of individuals to identify potential safety deficiencies while they continued to try to meet productivity targets.

Although the SR Technics QA program had a follow-up process for safety issues, as defined in the MOE, the implementation of the program was such that opportunities to identify potential safety issues were at times missed; as a consequence, safety-related follow-up was not undertaken on these occasions. For example, the map light anomalies were handled as a reliability issue; they were not identified as having flight safety implications.

The investigation did not attempt a direct comparison study to determine how the SR Technics QA program compared to QA-related programs at other operators. However, information was available from an FAA National Program Review report in which it completed a review of the maintenance organizations of nine of the largest US airlines.[116] The observations suggest that shortcomings identified in the SR Technics QA program were not unique. The FAA concluded that while the current state of the mandated QA-related programs in those nine airlines did not constitute an unsafe condition, each of them would benefit from reviewing and adapting their individual QA programs with the FAA's optimized model of the Continuing Analysis and Surveillance System (CASS) program. Similarly, analysis of the SR Technics QA program did not identify immediate flight safety concerns or unsafe conditions, although the program was not always effective in highlighting and resolving potential safety-related aspects.

The observations of the National Program Review results, by the US Department of Transportation's Office of the Inspector General (OIG), were of interest to this investigation. The OIG concluded that, in its oversight of the various CASS programs, the FAA focused primarily on whether the program had all the required elements, rather than on whether it was effective in detecting potential problems. The OIG made various recommendations that would require improved training, monitoring, and analysis of the CASS program. Analysis of the results of the FOCA audits of SR Technics showed a similar trend.

The similar nature of various FOCA audit findings indicates that they concentrated on ensuring that the QA program had the required elements. The findings tended to identify symptoms, rather than the underlying factors manifested in the recurring findings. Typically, the audits each contained several findings that questioned the adequacy and quality of personnel training, or the implementation and compliance of established practices and procedures. The FOCA accepted SR Technics' corrective actions, but made similar findings on subsequent audits. It was also noted that typically, the FOCA findings were comparable to those of the internal SR Technics audits.

[116]    The Federal Aviation Administration National Program Review Summary Report dated 8 December 2000.

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