This paper takes its point of departure in the years leading up to, and shortly after, the outbreak of World War One; a period that saw the emergence of Europe’s first aeroplanes. It argues that the production of new aerial objects required not just imaginative leaps in technology, but also the making of possible futures into which such technologies could fit. In order to elaborate this argument, the paper engages with the life and work of J.C.H Ellehammer, the Danish inventor-entrepreneur who claimed the honour of being the first man to fly in Europe in 1906. Through an examination of Ellehammer’s heterogeneous activities and practices, I argue that his initial aerial prototypes are ‘not-quite-yet-flying machines.’ As technologies of anticipation they model, or rehearse, a version of the future through which such machines could become more acceptable to a sceptical public and find their place within a broader national discourse on flying. This is based upon a particular reading of the prototype as both an epistemic object and an epistemic culture, and upon a rendering of prototyping as an analytic that approaches the craft and agency of objects in particular ways.