Before Richard Johnson's passing, I was communicating with him regarding a glider performance test (an ASW20) and he was kind enough to send me some Excel spreadsheets showing the parameters that he was focusing on. As expected, he used KTAS for the glide performance calculations. What caught me by surprise was his glide calculations used computed TRUE SINK as well. This might have made sense to me if he was measuring vertical speed with a rate instrument but unless I am mistaken, he measured sink rate using an altimeter and a stop watch.

I did not get the chance to ask him about this.

Nevertheless, he is missed.
Paul
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