Seaplane down off Miami Beach....
George Patterson wrote:
Jim Macklin wrote:
Reports I saws this morning said that the NTSB said they found a
fatigue crack in the main spar, maybe the conversion was not done well
or the maintenance was not though enough. I'll bet the fleet is
grounded and they require immediate, "before further flight" NDT
inspections of the wings, etc.
Chalk's has voluntarily grounded thier Mallards and is performing an
exhaustive test of the spars on one of them now. The NTSB rep voiced the
opinion that age alone would not be sufficient to cause this failure;
some additional stress would be required.
A pretty irresponsible statement for an NTSB person. Fatigue can cause
a stressed member to fail at a very low load, much less than even flight
loads. I seem to remember a picture of a Buff whose wing had failed on
the ground. It has been years and I don't remember the details, but it
seems like it was due to something fairly innocous such as refueling. I
believe fatigue was determined to be the root cause.
Matt
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