scope:

Description of Driving Event:

During air-arcing operations under mobile launch platform-1 (MLP), a welder smelled smoke through the hole he was working on and found a fire in the floor insulation of compartment 16B. Investigation revealed that air-arcing under MLP-1 ignited hydraulic fluid that had accumulated in the floor insulation of compartment 16B. Hydraulic pumping units leaked hydraulic fluid onto the insulation for several years. Hot particles released by air-arcing blew into compartment 16B as the welder penetrated the MLP bottom panel, and the fluid ignited.