Troubling story and some questions

On Dec 31, 6:10*am, "Byron Covey" wrote:
"Chris Rollings" wrote in message

...

Flutter speed (the normal cause of the break-up you
are concerned about) varies with altitude but not so
much as does the IAS.

Are you certain? *Isn't aero flutter a function of true airspeed?


My understanding has always been that the reason Vne drops with
altitude is that flutter is a TAS phenomenon.

9B

On Dec 31, 8:26*am, wrote:
On Dec 31, 6:10*am, "Byron Covey" wrote:

"Chris Rollings" wrote in message

...

Flutter speed (the normal cause of the break-up you
are concerned about) varies with altitude but not so
much as does the IAS.

Are you certain? *Isn't aero flutter a function of true airspeed?

My understanding has always been that the reason Vne drops with
altitude is that flutter is a TAS phenomenon.

9B

True sort of. I think what Chris is referring to is that it
apparently is not a simple direct relationship. Hard core wave pilots
and some aerodynamic experts can tell you why. It's a fairly esoteric
area. Each machine has different flutter characteristics, loading
varies... It really gets weird above 40k but even at 18k you can have
a bad day pushing the limits.

Matt Michael

wrote:
On Dec 31, 8:26 am, wrote:
On Dec 31, 6:10 am, "Byron Covey" wrote:

"Chris Rollings" wrote in message
...
Flutter speed (the normal cause of the break-up you
are concerned about) varies with altitude but not so
much as does the IAS.
Are you certain? Isn't aero flutter a function of true airspeed?
My understanding has always been that the reason Vne drops with
altitude is that flutter is a TAS phenomenon.

9B

True sort of. I think what Chris is referring to is that it
apparently is not a simple direct relationship. Hard core wave pilots
and some aerodynamic experts can tell you why. It's a fairly esoteric
area. Each machine has different flutter characteristics, loading
varies... It really gets weird above 40k but even at 18k you can have
a bad day pushing the limits.

Matt Michael
You might try googling Aeroelasticity. Several 800+ page academic text
books come up, each with extensive discussion of flutter. Not a simple
topic.

-Dave Leonard