MERC performed a series of tasks in the successful execution of the F-15 Fuel Cell Ergonomic Intervention.

First, MERC identified the ergonomic risks involved in the fuel cell build-up tasks required during the F-15 rebuild process.

Then MERC developed and implemented solutions which were acceptable to the mechanics and maintenance supervisors. Finally, MERC determined the overall return-on-investment derived from the intervention.

Building up fuel cells on the F-15 aircraft requires manually installing heavy rubber bladders, fitted with brass plumbing flanges, into 6 areas of the fuselage. After the plumbing is installed, the mechanics forcefully stuff pre-cut blocks of stiff, reticulated foam into each fuel tank to fill up all of the available space.

Ergonomic risks included: high finger loading, awkward postures leading to high exertion at extreme joint angles, high compressive loads for wrist, elbow, shoulders, and knees, high grip forces, and extreme heat and humidity.

Material characterization studies of the foam identified high friction and high compression forces as primary factors in creating ergonomic risk for stuffing foam. Compression forces were found to be temporarily reduced after full-depth compression.

These findings lead to the development of custom tools to facilitate the manipulation of bladder fittings, reduce friction forces between foam blocks, and pre-compress the blocks to temporarily reduce the compression forces required for stuffing the foam into place.

Overall ergonomic risk was reduced by more than 40%, while task time was reduced by 7 man-hours per plane, leading to savings of approximately $100k per year, with ROI of 6 months.

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