Columbia accident investigation board (CAIB) pathfinder analysis of item 33767

Abstract

Early in the shuttle Columbia crash investigation, item 33767 was one of several “Pathfinder” components selected from the Columbia debris that exhibited damage patterns similar to those observed on the left wing airframe components, the components in which initial failure was thought to have occurred. “Pathfinder Analysis” sought to answer academic questions regarding the maximum heat attained and heating direction/duration and identify debris imposed on this fuselage section during Columbia breakup and re-entry. Traditional failure analysis techniques provided useful information on debris constituents and damage sequence and were successful in identifying heat effects, such as the presence of large thermal gradients across the component, and the existence of several failure modes that included hot tensile failure, hot bending failure, and rapid overload fracture.