Originally Posted by
The Sultan
JD
Big differences between AH (unknown design deficiency), SA (known design deficiency), and 609/525 which were accidents which occurred during experimental flight test beyond the normal operating envelope. Problems with passenger carrying certified aircraft should be kept separate from aircraft in development.
The Sultan
Sultan,
The root cause of the S-92 MRGB incident I believe you are referring to was failure of the oil filter housing attachment. Of course, it was still a design problem that should have been caught. I would also argue that the EC225 MRGB bevel gear shaft failures were also something that should not have occurred. Fusion welding (electron beam or laser) of flight critical drivetrain components is a practice questioned by many design engineers in the industry.