Abstract : In designing regeneratively cooled thrust chambers, the heat transfer conditions are selected to avoid 'burnout' situations. Failure in engines using storable propellants during development, test, or operation seldom occurs by the burnout mechanism of design. Roughening, pinholing, tube cracking, or splitting are common occurences because of metal disintegration either on the combustion chamber side or internally within the tube due to two processes: (1) the combustion gases from nitrogen tetroxide and Aerozine-50 reacting with the stainless tubing (Type 347), and (2) the decomposition products of the Aerozine-50 degrading the interior of the tubes. A mechanism of tube deterioration is developed to give a chronology of the events occurring from initial tube carburization to final tube failure.