NavList:

Your plane was "spraying aviation kerosene over the nav gear", huh? That sounds... er... serious! :)

With a bubble sextant, but even a marine sextant, the solution you applied for a partially eclipsed is certainly valid, and I think most navigators could get excellent results by imagining and mentally extrapolating how the limb would be filled in. Plus it doesn't happen often. So it's not really a practical concern. I brought the problem up mostly because I thought some of the calculating specialists in the NavList community might find it an intriguing puzzle. For a modernized practical issue, consider an app that suggests good sight choices or at least stops a navigator from making bad choices with analysis tools. If I have taken a UL sight of the Sun suring a solar eclipse (marine sextant), and I get to my tools and select LL, here's one admittedly rare case where an app could ask "are you sure?" This would be a nice feature in any modern app (my GPS.a.Sp. apps currently do not do this but they should for Moon sights since it's a 50:50 thing). 

What are we looking for then? What should we be calculating? The edges of the "bite" in the Sun cannot take out the low point of the Sun --the point on the Sun's lower limb with exactly the same azimuth as the center of the Sun. That should be calculable. I haven't given it much further thought.

Frank Reed