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Ok, all, great info... Let me share a bit more after some
digging.
I heard back from Dave Morss. His setup is a little
different, it's actually a hybrid. His official statement is that it's an
MT prop with custom blades. Those blades were made by Aero
Composites. So We'll assume it's an MT hub, with Aerocomposites
blades.
Tim Ong rightfully shared the experience last year.
On the Sport class race, they quickly removed the MT/AC prop from Dave's Legacy
and replaced it with the Hartzell from 199L. Dave picked up at least 10
kts and it made the whole class a race for that position. Go look at the
times and you'll see how narrow those 4 Legacys were. However, this may
not be equivalent to what would happen with a full MT setup.
Ok, on to the MT topic. I just got off the phone with
MT. Here's the scoop. There is *NO* new airfoil on the blades, they
have been a scimitar design from the beginning (whenever that was). The
*DID* however come out with a counterweighted prop last year, but it's the same
blade design, with the counterweights added at the
bladeholder.
As for the discussion on the weight. I found that
53lbs on the mt-propellers.com website, however, in talking with the US MT gang,
they gave me a 56 (with spinner), for the non-counterweighted, and add about
6-7lbs for the counterweighted version (both of those are with
spinner).
So, to really put all of this in perspective, we'd need a
Legacy that has flown with the Hartzell at a known configuration, and with the
MT in the same configuration. I'm not sure we're going to make that
happen, so I guess we are back to ground zero.
Couple of other tidbits. The MT is 72" so on the RG
that might take up some ground clearance. On the FG if I go there, that
shouldn't be a problem as it set higher than the RG anyway.
So, there ya have it!
Alan
I have just recently installed a 3 blade MT on a Legacy with
the IO-550 and am curious where the 53# weight info comes from. I put it
on a good digital scale and it weighed 63#. This is a counterweighted prop
and the bulk of the weight seems to be in the hub as the blades appear to be
very light. One thing that appeals to me with this prop is that the
default (no oil pressure) position of the blades is in course pitch which is a
good thing when trying to glide with a dead engine. On the negative side,
however, is the fact that the MT spinner diameter is about 1/2 inch larger in
diameter than the Hartzell and the cowling is designed for the Hartzell,
apparently, and requires quite a bit of body work to fit the MT. Also, the
spinner on a Hartzell is fore and aft adjustable which makes it easier to get a
good spinner/cowling gap but the MT is in a fixed position. Haven't flown
it yet so can't give any performance data. Looks cool, though. We
report, you decide.
Leighton Mangels
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