<... VNE ( red line ) has to be established at 90% of demonstrated flutter-free
speed ...>
Well and good. But does the 200 kt VNE mean IAS at SL, or TAS
or IAS at any altitude or what??
I've heard that flutter is a function of both Q and V; that there is
both an IAS component and a TAS component to the issue. If that is
true, I don't know what the relationship might be. Additionally,
I am fairly certain that since he has all this power and all, John is going
to "expand the envelope" and explore airspeeds above the published 200
kts VNE. The key consideration IMO is what, exactly, is the safest
and most reliable way to expand the envelope? Explore higher TAS
at altitude (IAS at or below VNE) and having established a flutter free
TAS of, say, 250 kts TAS (+ 10% of course) to test at that TAS at lower
and lower altitudes until you've arrived at or close to 250 IAS?
Start out incrementally, say 5 kts at a time at low altitude and test that
IAS at progressively higher altitudes? What kind of test program
would get the job done safely and thoroughly?
Inquiring minds need to know .... Jim S.
Dean wrote:
Jim and John,
etal For single engine aircraft certificated
under FAR Part 23, the VNE ( red line ) has to be established at 90% of
demonstrated flutter-free speed. I would certainly think that it would
be in all home-built aircraft designers' interest to stay close to this
10% minimum margin when establishing the VNE for their design. You
might check with the Cozy designer. Dean
Van Winkle ( Retired Aero Engineer/Flight Test Engineer )RV-9A
Fus/Finish 13B NA
----- Original Message -----
Sent: Monday, May 03, 2004 9:41 AM
Subject: [FlyRotary] Re: Injector
testing
<... VNE
for the plans model Cozy IV is 220 mph ... if
I can cruise at 200 kts I'll be happy ...>
200 kts is
230 mph.
John Slade wrote:
>What
would be common for an O-360 powered plane? I
think VNE for the plans model Cozy IV is 220mph That's IAS for some reason
I never quite followed.> What
sort of top speed, and cruise speed do you expect? I
really don't know. If I can cruise at 200 kts I'll be happy. Anything over
that is gravy.
Top
speed is only for bragging rights anyway - right?John
(planning to beat all the RVs in races)
--
Jim Sower ... Destiny's Plaything
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
--
Jim Sower ... Destiny's Plaything
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
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