1 out of 200,000?? It seems like they would want that one back to analyze.
I'm sure most manufactures would want to take a look at it, for QA.
And,
"put the two LIGHTEST ones opposite each other on the hub," might be
a good idea, when the whole assembly is balanced. (The same blade doesn't always sink to the bottom).
I agree that a strong hub would be safer.
One question I would ask them:
Did
all of those 200,000 hubs, have those 3 big air-holes in them?
After reading the "THE GREAT CONE CONTROVERSY",
Wind turbine cones
I can't really see what good those big air holes in the hub would be,
if you are using a spinner cone.. (Which would block air flow into the holes).
Metal fatigue:
Is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading.
Bend a steel coat-hanger a few times, no problem. But bend it 20 times and it breaks..