Originally Posted by
OnePerRev
Okay, not good news here at all, but not surprising based on earlier photos we saw.
Next hard part is to determine "Why". Parts break when strength is exceeded by load. designers keep that from happening in theory, supported by testing. But if something breaks, you look at both ends of that basic equation. Was the part weaker than designed or are the loads higher than expected. If the former, due to quality issue, that can usually be contained. If the latter, then heads scratch on entire substantiation, heavy inspections, life limits, etc.
Also note (as stated earlier) the symmetry in fractures - and the number of parts affected. Less likely a quality issue, when affects multiple parts, unless same batch. There may well be a vibratory deflection content that was not anticipated, thus not deigned for. The issue that doomed Norne event was a resonance that AH discounted. They probably are paying attention now...
There is basically Zero chance of a Planetary Gearbox failure that won't result in total destruction, nature of the beast