This article explores the Concorde crash of 25 July 2000, seeking to show how law and regulation do crucial ontological work in the maintenance of commercial flight, and likely other aspects of modern techno-social arrangements. I argue that law and regulation cannot be seen as an exteriority, constraining and shaping the production of technology, but should be viewed as a component in the production of a physico-legal reality that a machine embodies. The Concorde disaster, by this logic, happened when that reality proved to be inadequate. It sparked a physical redesign of the aircraft, but also an intertwined effort to repair it normatively. Commercial flight is thus a total phenomenon comprising physical and social laws. This, I suggest, is the ontological significance of law and regulation in the production and maintenance of airliners.