On Saturday, October 5, 2013 12:48:27 PM UTC-5, son_of_flubber wrote:
I know that a 45 degree bank is useful for flying small circles and staying in small thermals, but is there something special about a 45 degree bank compared to say a 50 degree bank?



For example, does the designer intend for the glider to do something special at 45 degrees? Is the glider designed to balance aerodynamic forces in a particular harmony at a precise 45 degree bank?

Simple: the tan 45 deg is = 1 so you are #1, A-OK, top of the world, #1 flying ace, you get the drift! (don't drift when thermaling)
On the other side, the tan of 30 and 60 deg is a mess, don't go there!
Seriously, there seems to be a sweet spot around 45 deg where the radius flown at our thermaling speeds is keeping us closest to the high-climb values found at the center of the thermal without the penalty of higher wingloading and resulting higher stall speeds and overall higher sink at bank angles 50 deg.
Not sure this was helpful...
Herb