I only got to interact with him one time, but it left a lasting impression. When I was working on my Undergraduate Senior Design project, I was using Mattingly's "Elements of Propulsion – Gas Turbines and Rockets" to do my compressor and turbine matching calculations. There was a section that was unclear to me about what occurs when the turbine and nozzle are operating at a subcritical condition and how to estimate the performance. On a chance, I emailed him with my question and by the next day, he had sent me a very detailed explanation of how to deal with the matching equations when the turbine and nozzle are operating unchoked. It really helped and it always stuck with me that he took the time to explain it to some random undergrad student in NC, it really speaks to his passion for propulsion and education.
The world of gas turbine propulsion is a better world because of his mentoring and passion.