By definition, experts play a vital role in creating, sustaining, and disseminating any particular body of knowledge. But what constitutes an expert? How is authority obtained? Does this change over time? There are no absolute answers, which is to say that the question of who is considered to be an authority is culturally and socially constructed, and therefore interesting to historians. Here, I will consider the construction of authority in British aviation in the early twentieth century, paying particular attention to its manifestations in the public sphere.1 Because aeronautics was the subject of intense media scrutiny, but as yet lacked formal criteria for demonstrating expertise, anyone who wanted to claim the mantle of authority at some point had to come to terms with popular expectations.