Paul,
Have you seen the Aerocomposites cs units?
 http://www.aerocomposites.com/or
the MT, or Hoffman, for weight.....all are composite
 blade, oil fed
constant
speed units. Lighter weights. I've heard good reports from
 aerobatic (and
seaplane) pilots running some of them, esp the
 aerocomposite ones.
Marc Wiese
 MT and Hoffman have electric versions as well.
 Paul Lamar

 Paul, others.
 I have heard good things about Aero Composites but they
 are unwilling to
make a electric version.
This begs the question.Are electric C/S
 props  adequate for non
acrobatic flying?  If so it seems a shame to add the
 weight and
complexity of a belt driven prop governor, plus the
 hassles of the
hollow prop, shaft seals and  hoses etc.

 Doug in  Japan.
 Mark Steitle runs one so lets ask him. Mark how well does
 it work?

 Paul Lamar

 Paul,

 Bobby Hughes and I are both running 3-blade M/T electric
 props and we're
 both very happy with it.  I get great takeoff &
 climb performance (6800 -
 7200 rpm) and once at a safe altitude, I can dial it back
 for a more
 economical cruise climb (6000 rpm), and finally to economy
 cruise (5100-5200
 engine rpm).  The best feature is that I can change
 the prop pitch in flight
 if I want go fast.

 Not having an adjustable prop would be like riding a
 centrifugal clutch
 Cushman motor scooter, if you remember what those were
 like.

 Mark S.

 Gee, Mark, are you that old?  How about a Salsbury scooter?

 Joel
 Over the Hill Materials E.



Mark, what model MT prop/diameter and controller did you install and do you
remember the cost or did it produce selective amnesia?

Also, some folks report their MT electric control system has a significant
lag period between input and pitch change, especially in pattern, etc,
although the last time I flew one with a rotary engine I don't remember it
being that bad.  You?


Steve Beckham

Steve,

It has been years since I ordered my M/T prop.  I would have to dig out the
paperwork to find the model no.  It was a 76" as is recommended by Lancair.
I bought it through Jim Ayers who was doing a group buy, so I got a pretty
good price (relatively speaking).

I normally fly it with a combination of pitch and throttle, unless on long
x-country flights.  Then I normally fly WOT at 1700 prop rpm.  This gives me
around 5200 rpm on the engine and 158-160 TAS with a fuel burn of 11.3 gph.
If I need to go faster, I change to 1900 prop rpm.  If I really want to go
fast (190 TAS), and burn lots of fuel (20+ gph), I go to 2100-2200 prop rpm
with WOT.  I don't fly like this very often, but its nice to have options.

You're correct in that the electric controller is slow (slower than a
hydraulic), but you get used to it.  The method I've developed for landing
is this... a few miles out from the airport I adjust the prop to 1900, wait
for the engine to speed up and settle in to the new rpm, then switch the
prop controller from AUTO to MANUAL and then fly it like a fixed pitch from
there all the way to touchdown, adjusting speed with the throttle.  At this
setting the 20b has plenty of power to do a go-around if needed.

My takeoff setting is 2200 prop rpm.  With slippage, I'll see 7200 rpm
initially and then after a few hundred feet of ground roll it will bite and
rpm will drop down to about 6800.  (Because of this, I bring the power in
slowly, unlike a Cessna 152/172). This airplane really accelerates and
requires a bunch of right rudder to keep it on the centerline.  When clear
of the 50ft. obstacle, I start dialing the prop back slowly until I finally
reach my cruise setting of 1700/5200 rpm.  Last flight I saw 1600-1700 fpm
climb rate.  Not too bad for a 2100 lb. 4-place airplane running an auto
conversion.  I hope to see 2000 fpm climb rate once I get my new p-port
engine done.  ;-0

Mark S.