wrote on 4/10/2015 9:02 PM:
"Its also worth mentioning that Vne is not based on load factor, like
Va, but on flutter, which is why its True and not Indicated."

Actually flutter is dependent on equivalent airspeed not true
airspeed. There was an interesting article in Soaring magazine way
back where Stan Hall brought in a NASA aerodynamic expert
specializing in aeroelasticity and had his work peer reviewed by
other experts to try and get a definitive answer on a flutter
question arising from a flutter accident that led to several months
of "argument by letter to the editor."

"In my glider, the placard VNE is 146 knots IAS but at 18,000 ft this
is reduced to 122 knots IAS" Which brings up a question I've never
been able to get a good answer to: what methodology do they use to
determine reduced VNE with increasing altitude? Many gliders specify
just IAS and the gliders I've dealt with which do specify lower VNE's
with increasing altitude don't have those speeds match up with TAS at
those altitudes. Calculate what TAS at 18,000 for an IAS of 122 knots
actually is. It's higher than 146 knots.

As for the original question: where I fly the clouds are filled with
granite up to 7000 feet or more, the valleys are narrow and the
valley floors are not much above sea level. I don't have a turn and
slip or AH and I have only had minimal training on those instruments
over a decade ago in a Piper Cherokee. Being caught in cloud where I
fly I would probably opt for the parachute pretty damn quick. That
however is just the best of a bunch of bad options really.

According to the aerodynamicists I've talked, flutter at higher
altitudes is mostly dependent on TAS. The quirk is "at higher altitudes".

The "many gliders" you mention are likely older gliders, as Vne in TAS
is a "recent" change, where recent is about 25-30 years ago.

My 20 year old Schleicher ASH 26 E has a Vne of 146 knots from sea level
to 10,000 feet; there, the Vne = 146 knots IAS/175 knots TAS. That's why
the Vne in IAS at 18,000 calculates to higher than 146 knots - the Vne
is 175 TAS, not 146 TAS.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"

https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/...anes-2014A.pdf