Great thread guys.

As S Hannah stated, the best place to comment is on the IMAC site. These comments will all be taken into account before the BOD discussion and selection beginning next week.

Dean, I understand where you are coming from, but please point me to where it says a perfect geometrical snap contains no displacement. I have discussed this with several people and arrived at one way to look at it.

Consider the aircraft in autorotation as rotating around the outside of a cylinder. With one wing in a stalled condition, the aircraft's rotation is about an axis located somewhere out on the stalled wing. If you are performing one full snap, theoretically the airplane will make one rotation about that axis and end up in the same spot. It is when you do fractional snaps, especially the half snap, that the airplane will rotate partially around this "cylinder" and exit at a different spot. This is how displacement in a perfect snap can be justified.

Please, don't read this as a definition I've found somewhere, just one theory derived from a bunch of dumb pilots talking aerodynamics. ;-)

Daniel Rathbun
South Central RD