NavList:

Paul,

As for conventions for writing equations, you are right that computer languages all put the variable that receives the value on the left.  I got my elementary and secondary education before computers were ubiquitous, and the convention I learned in school put that variable on the right...along the lines of a² + b² = c², rather than c² = a² + b².  Writing Bygrave equations as I did simply came natural to me as I was seeking to develop a worksheet for use with a non-electronic method of sight reduction.

As for the azimuth outputs, my worksheet is wrong, wrong, wrong.  Thank you so much for pointing this out!!  The mystery to me now is how I managed to always work out problems on my own where my method worked.  Those were clearly misleading results.  I have gone back to Gary LaPook's worksheet at:

https://sites.google.com/site/fredienoonan/other-flight-navigation-information/modern-bygrave-slide-rule

...and his azimuth rules definitely work great for the first example you sent.  I need to go back and work some more problems myself, and get myself at home with Gary's azimuth rules, and make modifications to my worksheet.

Again, Paul, thank you for pointing this out.

Gary, do you have azimuth-rule suggestions for rhumb line calculations?  It seems likely that if I got azimuth wrong for great circle routes, I may well have gotten my rhumb line calculations wrong as well.

Bob