B-2A accident investigation board

Flying Safety, August, 2003

The T.O. job guides for this particular maintenance action allowed steps to be accomplished in no particular order. However, common sense required doing maintenance actions sequentially or as the job guide listed the events. However, the AIB found that A/R shop personnel routinely took non-job guide shortcuts for this particular task without the knowledge of their supervisors. The particular shortcut of pulling the landing gear safety pin and pushing up on the lock-link assembly had been used by A/R shop personnel long before MMT1 arrived. This technique is not authorized by the tech order job guides. MMT1 stated he had removed the pin and pushed up on the lock-link assembly on previous occasions without anything happening. He also believed that it was impossible for the gear to collapse as a result of these actions. Even after the mishap, he still felt that his actions alone, with aircraft weight on the landing gear, could not have caused the collapse?

MMT2 was asked to assist MMT1 during the mishap. He, too, received the same training as MMT1, but stated he "was not one for" taking the shortcut of removing a safety pin and pushing up on the lock-link assembly. He had seen it done in the past, but had never done it himself. He, too, had an impression that nothing was going to happen because of prior apparent success using this shortcut. MMT2 expressed a great deal of respect for MMT1 and stated he would not have questioned MMT1's actions because MMT1 knew what he was doing. He further explained that he saw MMT1 do this before, but never questioned it.

As MMT1 performed the actions leading to the mishap, other specialists did not question his actions because they were not sure what he was doing. The team that was formed the morning of the mishap was supposed to organize the actions to be performed by various maintenance specialists, but the extent of this organized effort primarily focused on the overall goal of using cockpit indications to adjust the main landing gear sensor components.

No one questioned whether this troubleshooting team needed to be a part of a formal Technical Order Validation and Verification. One thing became clear after the meeting: this was not routine maintenance and there was still confusion on exactly what was to be done. From the testimony of the witnesses interviewed, the AIB reached several conclusions:

* First, this B-2 maintenance tiger team did not perceive potential safety risks associated with the use of landing gear shortcut procedures.

* Second, supervisors had limited exposure to the day-to-day work practices of the individuals they supervised.

* Third, training continuity suffered because of additional taskings outside the maintenance duties of squadron personnel, Security Forces augmentee duties.

* Fourth, an outside inspection of B-2A maintenance practices in the A/R shop was ineffective in detecting training deficiencies.

* Fifth, B-2A technical orders are still in a maturing stage and are not all-inclusive.

* Sixth, individuals were complacent to dangerous B-2A maintenance practices that were performed routinely.