Originally Posted by
etudiant
Perhaps there is some peculiarity in the manufacturing process which produces these variations in the blade sensitivity. Materials are often poorly understood, so sometimes a processing step turns out to be detrimental rather than beneficial.
Finding out which is very difficult, especially with a flight critical component.
As an adhesive bond failure forensics specialist, I am very familiar with issues relating to the -5 blades, but I was far more confident with the -7 blade processes, so I am very surprised and interested in comments about current disbond (NOT delamination, different fault, different cause) occurrences. Aarj, can you please PM me any details, photos etc. of these occurrences?
Before the suspicions start, NO, I am not a lawyer, journalist or other parasite and I am not a total Robbie basher. Google "A08_25_29 Recommendation" and realise that my input directly led to that report. My issue is that while it is regulated that for certification it is required that an OEM must demonstrate static strength, fatigue resistance and damage tolerance, but there is no current regulatory requirement to demonstrate that an adhesive bond must maintain structural integrity over the entire component (non-fatigue related) life. That is what the report finds.
Regards
Blakmax
Blakmax