Jardur Model V Flight Calculator (c. 1940): What you see is what you get

The Jardur Import Company was founded in 1937 and produced a variety of pilot supplies, including calculators, plotters, and aviation chronographs. Jardur produced at least three different flight calculator models, including the Model V, Model H, and the Super Flightmaster. In this video, we take a look at the unique design of the Model V calculator, namely its use of "incomplete" (i.e., non-wrap around) scales. To do so, we follow the on-device instructions to solve both a standard wind problem as well as a time-rate distance problem, and we note some of the idiosyncrasies along the way. 00:00 – 1. Introduction 01:21 – 2. The wind side 02:38 – 3. Wind triangle example 04:52 - 4. Limitations of the wind side 05:45 – 5. Limitations of the time-speed-distance side 07:30 – 6. Time-speed-distance problem 08:07 – 7. Comparison with an E-6B 09:19 – 8. Conclusion Notes: Within the last problem of "How long will it take to fly 400nm" I should have written "statute miles!" Units matter and this was quite the goof. In addition to writing "nm" I also say nautical miles a few times. For completeness, 400 nautical miles would be about 460 statute miles, and at 172mph it would take about 2 hours and 40 minutes to fly that distance. Had I written "How long will it take to fly 400sm," the answer would be as-is in the video (2h and 20m). Apologies! Other Appearances: Motorola "Co-pilot" Calculator (Perrygraf), Dennert & Pape DR2 Dreieckrechner (1940), U.S. Army Air Corps E-6B, Keuffel & Esser (1940) #jardur #modelV #e6b #aviation #flightcomputer #deadreckoning #navigation #math #history #pilottraining #dreieckrechner