Prevailing Cultural / Organizational Factors

Maintenance supervisors at Air Transat did not review service bulletins having an optional or recommended compliance. Such service bulletins were reviewed by Air Transat Engineering. The result was that while maintenance crews may have been aware of specific service bulletins, they were not part of the decision for incorporation of those service bulletins. Neither the hydraulic pump installation nor the engine build-up service bulletins were reviewed by Engineering because all of Air Transat's A330 airplanes had been delivered with the post-mod configuration. The airline did not consider the possibility of a replacement engine might be installed on one of those airplanes that had not yet been modified. As such, they did not have a process for reviewing and tracking the incorporation status of relevant service bulletins on their airplanes for non-mandatory service bulletins.

Although electronic copies of these service bulletins were available from other sources at the facility where the engine change occurred, the lead maintenance technician was not aware of these other sources. The Maintenance Control Center technician, who was aware of the other sources, did not tell him. The Maintenance Control Center technician's role was to locate resources for the maintenance technicians, and not to provide technical assistance in searching for technical references. Also, even though a Rolls-Royce company representative very familiar with the hydraulic pump modification offered his assistance to the Maintenance Control Center technician to attend the on-site engine change, his offer was not taken. Although both the Maintenance Control Center technician and the lead maintenance technician were concerned about the inability to access the service bulletins from the company computer network, the time pressure to complete the engine change seemed to play a role in moving ahead without copies of these service bulletins. The Maintenance Control Center technician did have knowledge of the engine build-up service bulletin and the background behind it, and this knowledge gave comfort to the lead maintenance technician in the decision to go forward without consulting the service bulletin.

Making a decision on a modification that affects the safety of an airplane based on only partial knowledge of the modification requirements with no process within the airline to review and track such non-mandatory modifications contributed to the interference between the fuel and hydraulic lines that led to the right engine fuel leak.

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