Bruce Greeff wrote:

First generation glass, before the finite element analysis programs
allowed the designers to design to the limit is probably much safer to
over stress than overspeed. Similarly the latest carbon designs seem to
have G limits imposed by the JAR22 deflection limits rather than
ultimate strength. Presumably these aircraft have huge strength
reserves. For interest look at the wing test on the DG1000.

I agree that *some* earlier, 15m designs may have a good safety margin
in overstress, mostly those in glassfiber (more flexible).

But not *all*, and certainly not modern open-class gliders.

I recall what I posted before, because there are facts from NTSB and
manufacturer data, which I think are more reliable than some honorable
but ill-based opinions expressed in this thread, and which nobody here
have contested yet:

the link (on Minden Nimbus 4 accident) :
http://www.ntsb.gov/NTSB/brief.asp?e...12X19310&key=1
(...)
The report quotes that the G limit for the Nimbus 4 at VNE is 3.5 g
*only* (compared to 5.3 g at Va) and the design "safety margin" is
between 1.55 to 1.75. Thus even on a plane in perfect condition, and if
the manufacturer made no mistake, it *will* break between 5.4 and 6.1 g
at VNE (even without airbrakes)

--
Denis

R. Parce que ça rompt le cours normal de la conversation !!!
Q. Pourquoi ne faut-il pas répondre au-dessus de la question ?