As a mere pilot these technical explanations appear to reveal a situation in which the manufacturers of these gearboxes know from the outset that they are full of imperfections due to the very concepts behind their design. They then rely on being able to detect the inevitable failure courtesy of the infamous chip detector system. When this detection mechanism is found to have holes in it surely that puts the whole design philosophy behind this type of gearbox into question. How can the certification authorities support the notion that all is well in the helicopter transmission business? Is this behind the UKCAA and NCAA approach? How come the EASA experts don't get it? What kind of world are we living in?
G.