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Old July 7th 04, 07:38 PM
Luke Scharf
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On Wed, 07 Jul 2004 17:54:59 +0000, Mike Rapoport wrote:
Gee what do you think the indicated airspeed is at M.85 at FL350?


It looks like the calibrated[0] airspeed is around 325mph:
https://ewhdbks.mugu.navy.mil/mach-as.htm

I seem to remember that Mach 0.85 is transonic, so air is actually flowing
at supersonic speeds over some parts of the airplane (nose, wings, tail?)
and subsonic over others. All kinds of stuff that I don't know how to
predict happens then. Maybe someone here is an aerodynamicist who has a
better feel for compressible flow?

But, *that* is why I am skeptical of the Mythbuster's conclusion -- it
seems to me that supersonic/transonic airflow anywhere would be a
significant consideration -- especially if the flow happens to
be over the bullet-hole.

-Luke

[0] IIRC, "indicated" airspeed isn't valid above Mach 0.3 because of
compressibility effects -- but it has been quite some time since I took
that class (and I wasn't proud of my grade) so I could be very wrong. I
have just enough education on the topic to appreciate the expertise of
people who actually know what they're talking about!