"Stu Fields" wrote in message
...
It seems that if there are two possible causes for a helicopter accident,
the preferred one for the manufacturer is the one for which they have no
fault. That certainly is the best for them. However, lets say that a low
hour helicopter suffers a failure directly attibutable to fatigue.
Further lets assume that the helicopter had had a prior series of hard
landings or other beyond normal stress loadings. Now lets further assume
that the fatigue failure occurred at a point in the helicopter drive
system where a diameter change was machined into the shaft without any
radius or attempt at a proper fillet which yielded a strong stress riser.
Lets say that the kit manufacturer is very aware that a number of kits
have been sold with the same machining flaw.
Should the kit manufacturer issue a service advisory statement advising
all owners of those ships of a potential safety issue caused by those
parts? What should their action be? Recall and supply exchange parts for
no charge? Recall and supply exchange parts for their cost? Change the
machining process and ignore the other parts out there?
How about sell the business to someone else and just duck and hope that
nothing bad ever comes from the above?


Hi Stu,

You mention a lot of variables here. My thoughts are this - first, why did
the bird have a series of hard landings or other "beyond normal stress
loadings?" Those, to me, sound like a piloting issue and not necessarily
the kit manufacturers problem. Second, if the kit manufacturer discovers
that they're selling parts that do have some kind of defect in design or
machining, I think they should be obligated to making that right, either by
an outright recall or by offering proper replacements to kit owners at cost.
At the very least, they should issue a service advisory statement on the
problem to be certain that the kit owners are aware it.

Having said that, we are talking about "experimental" aircraft here. If I
understand all that correctly, that means the owner/builder "is" the
manufacturer of the aircraft and is ultimately the one responsible for the
safe operation and maintenance of said aircraft. Still, if the kit
manufacturer has any integrity, they'll be doing all they can to assist
their customers with parts and materials that are discovered to be less than
ideal for the job it's asked to do.

I'm reminded of something Air Command did many years ago when they finally
came around to the benefits of an in-line thrust design for pusher style
gyroplanes. If I'm remembering correctly, they issued a statement advising
anyone owning the older/original design bird to stop flying them and offered
a new frame upgrade with a center line thrust design to "any" owner, "at
cost," regardless of whether those owners bought the bird directly from Air
Command or from an individual. I think it took a lot of guts for them to do
that and speaks volumes for the integrity of the company.

Does that answer your question? At least it might help spark the
conversation! :-)

Fly Safe,
Steve R.