Speke: Yes, they weren't the best examples, but I was just "dashing off" a quick reply. I thought later it might have made the point better by comparing the mil "diversion airfield" with the civvy "alternate airport". I'm just recalling conversational usage rather than R/T. In conversation, (Caveats: In my time / In my part of the Air Force) no-one would have used "Aerodrome / Airport" in conversation. Only "Airfield".