(45) Air Navigation with a Pocket Electronic Calculator - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: General Software Library (/forum-13.html) +--- Thread: (45) Air Navigation with a Pocket Electronic Calculator (/thread-12176.html) (45) Air Navigation with a Pocket Electronic Calculator - SlideRule - 01-13-2019 02:59 PM SOME navigators may prefer other methods and other tools, but the Hewlett Packard HP-45 has some fascinating abilities. It might be called the poor man's INS computer, though it does not of course find position. Its only disadvantages are the need for a hood in sunlight and the need for concentration and freedom from distraction. It can be used on the knee for no table is required, and it replaces conversion tables and several other mathematical tables. To a large extent it can replace plotting charts, flight planning charts, Dalton computers, protractors and dividers. It simplifies ground speed/distance/time and fuel calculations especially, with its ability simply to convert hours, minutes and seconds or degrees, minutes and seconds to and from decimals. It calculates in the decimal mode … the rest of the article Air Navigation with a Pocket Electronic Calculator, completes the exegesis for an HP-45 with respect to allowable (> 1000 mi.) straight-line air navigation; replete with formulas, illustrations, descriptions, key-code routine(s), etc. BEST! SlideRule RE: (45) Air Navigation with a Pocket Electronic Calculator - StephenG1CMZ - 01-13-2019 03:37 PM I guessed allowable > 1000 was meant to say allowable < 1000, since its the larger distances where the straight-line approximation of a sphere is more noticeable. But the text does indeed refer to distances over 1000 miles in US and Canada... Which leaves me wondering whether other countries were more accurate, or simply using km instead of miles. RE: (45) Air Navigation with a Pocket Electronic Calculator - SlideRule - 01-13-2019 03:58 PM In my first draft, I put ≤ in rather than >: went with the article for clarity. BEST! SlideRule