Mark James Boyd wrote:

But I must say I don't entirely understand WHY flutter
is based on TAS.

it's not. It is only because the IAS at which flutter happens is likely
to vary with altitude (it may be lower or higher !) that some
manufacturers and/or authorities limit the VNE at a constant TAS above
2000 or 3000 m (i.e. the altitude where tests have been conducted)


I also don't know if the IGC cares
if Vne is exceeded during a world record.

IGC don't care of exceeding any limit, with the exception of legal
day/night flight rules.

I think there is still a provision that the record may only be validated
if the glider lands back in one piece (that rule was set after some
altitude gains in CuNimbs where the pilot had jumped with the barogramm
after his glider broke ;-)

Only in championships you must have a valid permit-to-fly and respect
the limitations of your glider (weight, etc.)


--
Denis
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