Black Magic and Gremlins

This publication discusses how we developed the many different analog simulations.However, it is also important to mention the reasons why we did so. For this purpose I have included in the appendices a copy of a paper by Dick Day, “Training Considerations During the X-15 Development,” which was presented to the Training Advisory Committee of the National Security Industrial Association in November 1959. In this paper, Dick talks about the early use of analog computers to study instabilities that were occurring with the X-1, X-2, X-3, and some of the century series aircraft. Dick Day was an active participant in the early use of analog computers at the NACA HSFS to study the problems that were being encountered by the pilots during the testing of these vehicles. His paper explains the reasons that analog computers were originally bought and used for real-time flight simulators and why flight simulators are still being developed and used at the Dryden Flight Research Center. This paper by Dick Day plus the comments from Dick Banner (in the section on analog simulations and in his personal account) provide a good introduction to the events that began it all, and why it all happened.