One month already…

… since publication on the App store. But that is only the beginning of the journey.

The time since that milestone has been one for me to take a step back and reflect on how this project has evolved. It started out as a “quick-and-dirty” program written for my own use only, to simulate a slide-rule flight computer. It was during that process that I realized how clever and remarkably accurate these mechanical slide rules actually are. Especially given that they were created a long time ago, in a time where “electronic” computers were in their infancy, or just plain didn’t exist. I always had a circular slide-rule in my flightbag, and just used it when needed, but without giving it any thought. Now my hat is definitely off to the designers of those slide rules.

Another aspect that struck me is the amount of detailed knowledge that had already been gathered about our atmosphere long before the commercial jet age began in earnest. The amount of painstaking research that must have gone into this is staggering. One of the documents I came across while researching airspeed equations was originally issued by NACA, the precursor to NASA. It is entitled “A Simplified Chart For Determining Mach Number And True Airspeed From Airspeed Indicator Readings“. And it is from 1943, typewritten and with hand-drawn charts. The “U.S. Standard Atmosphere” document, from 1962, is another early document that is chock-full of incredible details. And the 1976 edition of this publication was instrumental during development of the App.

But most impressive of all is that this information, and much more, including very recent material, has been made publicly available, in particular by NASA. They chose to share it, rather than to keep the materials under lock and key. And it is not only NASA. In my research, I keep coming across countless examples of information sharing, by individuals and by organizations, without which making this App would have been impossible. From creators of online calculators which have allowed me to check the accuracy of my own work (and sometimes the lack thereof), through to Ph.D.’s who are also aviation enthusiasts writing detailed explanations of complex systems and processes, to forums such as StackOverflow/StackExchange that provided answers to many a programming question not answered by the documentation, literally hundreds of people have influenced this work. To all of you I owe thanks.

And finally, a shoutout to the crews I flew with and worked with over the course of the last 25 years. We have thankfully become old pilots / old crew! And what great fun it has been trying to get to that “bar in far Bombay”! Still haven’t made it there, darn it!!

So what’s next? Well, I am working on additional features, which will result in at least one additional calculation tab. Expected release end of June 2020.

Until then, cheers!