Crikey Snoopy, we agree on the lack of sense in these postings:
It hasn't only happened in "bad" environments with over-stressed components and timed-out machinery.
Actually the Appendix to aair200302820_001 VH OHA lists details of two blades with disbonds in the root fitting with
ZERO flight hours. They disbonded in storage. I can just see Robbo Engineers explanation "Maybe they dropped the box".
I was hoping that the issue of bond manufacturing processes had been addressed in the -7 blades. The recent ADs relate to cracking which may or may not be a consequence of bonding issues. We will wait and see. Hopefully the Kiwis have expertise in bond issues which may (or may not) provide causal effects rather than just focusing on the crack.
As a specialist in the field of adhesive bond failure forensics I can assure everyone that interfacial failure is NOT caused by loads. It is directly related to the processes used for surface preparation at the time of manufacture, and the disbonds I have seen exhibit lots of adhesion failure. There is also a lot of mixed-mode failure which is a mixture of weak adhesion failure and some cohesion failure. Cohesion failure is the strongest, and in all the surfaces I examined there was not a trace of true cohesion failure.
This issue is too important to be fobbed of by Robbo.
Regards
Blakmax
PS welcome back Snoopy.