At 21:33 22 September 2010, John Smith wrote:
cernauta wrote:
On Wed, 22 Sep 2010 17:30:25 +0200, John Smith
wrote:


Modern gliders tend to be certified to JAR-22. Non-acro gliders are
certified in the utility category which means a max. load factor of
+5.3G at maneuvre speed and +4G at Vne. Safety factor ist 1.5 (for a
new
glider, probably less for a worn-out one!).


chances are you will break a glider when pulling 8G at Vne. 8G are
perfectly standable (albeit for most peoole not enjoyable).

Should I read 6G, I guess.

Of course, my mistake. I had it correct, then reviewed it, mixed up the
Gs at Va and Vne and "corrected" it. Oh well.

I think we are getting a little away from the point. The original
proposition that pulling G in any glider would result in failure. I
suggested that catostropic failure would not necessarily occur in many
gliders. The certified load factors do not necessarily indicate the actual
load factor that an airframe can sustain. The RAF bought 100 Grob Acros, 99
went into service and 1 went to Slingsby for testing on a rig. It was as
the result of this testing that the spigot problem was indentified. After
the airframe had been tested beyond the expected life by a considerable
margin Slingsbys were asked to apply loads sufficient to break the
airframe. They were unable to do so, and after breaking the rig several
times trying, gave up.