"Roger Halstead" wrote in message
...
On Wed, 24 Dec 2003 23:18:41 GMT, "Mike Rapoport"
wrote:


"Roy Smith" wrote in message
...
Scott Skylane wrote:
These have been around for quite a while, and they are nothing but an
exercise in compromises.

All airplanes are an exercise in compromises.

First, there is no "yellow arc" allowed on the
airspeed indicator, so redline becomes top of the green.

I know turbines don't have a yellow arc, but I never understood the
logic behind that. Vno (bottom of the yellow arc) is determined by
airframe factors -- IIRC, the ability of the wings to handle the
stresses from vertical gusts. How does taking out pistons and putting
in fan blades change how the airframe reacts to stresses?

It doesn't, turbines are just rated more conservatively. There is
nothing
magic about these numbers. Vne is simply 90% of Vd (maximium
demonstrated

According to Bell in "Those Incompairable Bonanzas" Vne is 80% of the
tested dive speed in the Bo, where it is 90% in almost all other
aircraft.

90% of Vd is the maximium that Vne can be. Some airplanes have a Vne lower
than 90% of Vd for various reasons. In the MU-2 Vd is 345kts and Vmo is
only 250kts or 72%. It had something to due with the CAR 3 standard that it
was certified under and the fact that the early MU-2s couldn't do 250kts
indicated in level flight anyway. Even though the later models have almost
twice the power as the originals and will easily reach 250kts indicated as
high as 16,000', the 250kts Vmo was left unchanged.

Mike
MU-2

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
dive speed), and Vno (Vmo in turbines) is simply 80%. Barry Schiff has a
discussion of V speeds in one of his books.

Mike
MU-2


This restricts you to pretty low true airspeeds at breathable
altitudes. Stay down low, go slow and burn A LOT of gas. Go up
high, go fast, and suck on a nose bag.

But oh man, think of the climb rates you must get!