http://ozreport.com/forum/viewtopic.php?t=33249&start=36

My local Aeros dealer received this explanation from Aeros (and
they later confirmed that it should be shared in this thread):

"All carbon crossbeams used by Aeros are tested by our crossbeam supplier. At
some stage both bending and torsional tests were performed. Since some time only
bending tests were made, as bending is the load most critical for the crossbeam.
Normally torsion is not as important in this application. However, it was made
critical by the manufacturing mistake. The infrequent manufacturing defect to
which we were referring in the Safety Directive-016 is displacement of a carbon
fabric layer while the crossbeam preform is compressed in the course of
production process. This can result in a weak line forming along the crossbeam
wall. And this is what happened on both crossbeams that failed. The incidents
made us renew factory torsional tests of the crossbeams. Of course we are now
re-testing carbon crossbeams on all Combat gliders that were waiting for
delivery at the factory. And as we already know about the possible problem, from
now on every carbon crossbeam will definitely undergo both bending and torsion
test as a part of production control."