On Monday, June 10, 2013 2:07:55 PM UTC-4, kd6veb wrote:

For lighter gliders up to 1320lbs max weight we have a very viable option in the US and that is SLSA category. My Phoenix in in this category. As far as I understand it there are no real negatives but one perceived negative and that is the max VNE has to be 120 knots. Why? Only the FAA with its infinite wisdom knows why!


My principle credential for weighing in on this question is that I own a glider classified experimental with a VNE of 120 knots and I've given it some thought.

The manufacturers of LSA are regulated more lightly than the makers of other aircraft. I'd guess that at some point in history, experience told the regulators that the incidence of problems (like flutter) increased rapidly above 120 knots. Thus it would be reasonable to more lightly regulate the manufacturers of aircraft that had a VNE less than 120 knots.

Now that manufacturing technology has changed (and not necessarily for the better), the 120 knot may be too high or too low. Once upon a time, 120 knots made sense.