Al Gietzen wrote:

Also, users find that twisting the blade does quite a lot of good in
reducing takeoff roll over fixed pitch, and as good as variable pitch.

I would be very surprised at that. I wonder if anyone actually tested a

real

constant speed prop back to back with a variable twist IVO.

A number of Velocities are using the IVO props with Franklin 220 engines,
and at least one XL with a Lyc 540 that I know of.  All are very pleased
with takeoff and climb performance.  There are also Velocities flying with
Franklins and MT's; and Lyc 360s and MT's.  The word from a guy who has
flown most of the combinations says he'd rate the IVO and MT "pretty
comparable" on takeoff performance.  Perhaps not an 'actual test'; but . . .

Just reporting what I know.  I'm not interested in a IVO because with a 20B
in my standard-wing Velocity I'm looking for good high end performance, and
I remain a bit uncomfortable about IVO's reliability history.  So, how soon
can we expect a 3-blade version of CS prop you guys are working on?

Al Gietzen

We are a long way from a three blade.

Paul Lamar
 
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