Le samedi 29 septembre 2018 17:45:07 UTC+2, Nick Kennedy a écritÂ*:
A couple of observations from the cheap seats:
It sure looks like to me over the years there have been way too many Shempp Hirth Open class gliders going in; now with a latest rash of two seat motor equipped ships losing control and coming apart in the air for no obvious reason.
I have NO faith in the NTSB getting to the bottom of any of this. AFAIK the Nephi Arcus fuselage is still in the forest up by Monroe Peak Ut. I thought a loss of control surfaces was a major red flag and cause for a real investigation. Kinda hard to do a investigation when the fuselage after 3 months is still in the woods.
Concerning the Glider Bob Saunders Stemme NTSB investigation and final report,I found to be shallow and half assed at best. I never went to the crash sight, I wish I had now, to look at it with my own eyes to see what really happened. See where the engine switch's were and the engine controls etc etc.
Jonathan stated he knows of 7,7!! Nimbus 4's that have had the wings come off in flight, Holy S*%#t that's a lot!
These gliders we fly are built and stressed tested to take huge loads and most of the time do quite well; why are some coming apart? Design defects? FOD? Poor Maintenance, incorrect assembly, poor piloting skills? All of the above?
Or are all these accidents just the actual statistical odds catching up to us?
I wonder as several of these ships have obviously had control failures. And that is a tough nut to swallow. If I thought there was any history of my LS3a failing me I would not fly it, period. But people continue to fly those 2 place Shempp Hirth ships with and without motors, god bless them, they are braver than me! But this point I would not climb in one, but that's just me, there I said it. Something is obviously screwed up in those planes..
Keep the rubber side down and the shiny side up.

In any open class two-seater, once you've done a full turn in a spin, you are very likely to lose your wings.
The angular momentum of these wings plus the fuselage is about 4 times higher than that of a 15 m ship, but the rudder is only twice as large - so it will take more twice the time to stop the rotation, all the while accelerating vertically. Little chance *not* to exceed vne.