As a former full time flight instructor, I took a large interest in this publication, as the school I worked at was listed in two of the fatals. I had the opportunity to talk with the owner of the school about the incidents, as I was not employed at the time of the accidents. What was brought about in my talking has been shared very little and is obviously opinion, but does seem to make sense. I encourage any Robinson pilot to become familiar with this report and learn from it.
I hear a lot of discussion about the safety record of the Robinson and believe most accidents post '95 are more than likely due to pilot error, but the ones in this report are probably not, hence the need for the investigation. It has been argued that since the SFAR73 that the fatality rate has decreased significantly, which is true, but possibly misleading. At the same time it was found necessary by the FAA to issue AD 95-06-03. This may be the reason for the decrease in MR blade divergence. The info put out in the Safety course was not new by any stretch, and was being presented for years up to that point. Simply making it mandatory should not have the effect that most perpetuate. As any manufacturer would like you to believe, their product is not defective, and the problems associated must be with the operator, and residing in the US one could not accept blame and continue to do business what with all the lawyers around. As shown in the NTSB report, pilot error could not continue to be sited once there was audio recording that showed no obvious error in pilotage. It may be possible that the mast bolts being improperly installed could have caused an in-flight condition that would result in a negative pitch in the blades that would in turn, have the same result as a blade stall either coming through the cockpit or severing the tail boom. As a manufacturer it would not be prudent to point out a potential design flaw if you wanted to keep manufacturing helicopters or live in a house any longer.
Just my two cents.