We were only one month into a dynamic P-3C Orion deployment in the 5th Fleet area of responsibility (AOR) when the rudder-boost-package actuator began leaking out of limits on one of our aircraft. Normally, the solution is as simple as replacing the packing in the actuator, but not this time. During the removal inspection, we discovered that the actuator was corroded internally.
With the nearest replacement actuator located in the supply
chain in Pearl Harbor, Hawaii, (and the aircraft scheduled for an “early go” the following morning), maintenance control decided to
cannibalize the actuator off another aircraft. That aircraft had been
“downed” for an extended fuel-cell maintenance procedure.
The airframe technician charged with removing the good actuator was a seasoned maintainer but only had been working on P-3Cs for about a year. The maintainer was familiar with the installation procedures but had no experience removing an actuator. The airframe work center had a heavy workload on that particular night, so the technician- in-charge requested the help of the night-shift
The two maintainers checked out the required tools and went to work at approximately 2200, knowing they only would have about five hours to cannibalize the good actuator from one aircraft and install it on the other, perform leak and operational checks, and take a hydraulic contamination sampling. No problem, right?
The rudder-boost actuator is located in a tight space in the empennage of the P-3C, which leaves little room to work and almost no light to review the maintenance checklist. The maintainers staged the appropriate publications outside the empennage- access panel on the maintenance stand. The on-scene QAR wanted to teach the other technicians how to remove the actuator from the
boost assembly, so he agreed to perform the maintenance functions.
Meanwhile, one technician CDI’d his work, and several others observed. With a deadline looming, both the QAR and CDI failed to read through each step in the checklist and inadvertently skipped a step in the removal procedures. The skipped step required installation of a rudder batten if the aircraft was slated to
be outside for an extended period of time with the linkage disconnected. The rudder batten is a tool designed to prevent the rudder from moving.
With a sense of accomplishment, the maintainers met the challenge, accounted for all tools, and ensured the work order was signed off before the aircrew showed up the next morning for preflight checks. Every metric indicated a completely successful maintenance evolution. However, when the desert winds increased the following day, the unsecured rudder on the cannibalized aircraft
began to blow violently from side-to- side, tearing the aircraft “skin” in three places. Both viscous damper arms (and associated brackets) also were bent. The situation could have been more severe had it not been caught so early. Regardless, it took three days, 150 man- hours, and $900 in parts to repair the
damage—all completely avoidable, if only the maintainers had followed the checklist during the original maintenance evolution.
With limited parts, people and financial resources in today’s Navy, there is no room for these kinds of mistakes in aviation maintenance. Ensure that the appropriate publications are followed step-by-step every time. Anything less is unacceptable.
Source: Aviation Human Factors Industry News, Issue 20