Subject: Great day to fly!
From: Rotary Engine
Date: 1/9/2007, 10:11 PM
To: AARotary Engine


I finally got a great day to fly and nothing I had to fix.  OAT - 30F,
Wind - 0. Only hindrances were the snow drifts on the taxiways.  I had
to dig my way out twice when I got a little too far off the path
scraped clear by the city.

I checked the Hobbs as I lifted off, 9.5.  After flying around for a
while getting a feel for the plane at different power settings and
doing some turns I noticed the Hobbs was 9.9.  Flew some more and the
Hobbs was 9.9.  Huh! it must have just clicked over last time I
looked.  Checked my watch and five minutes later the Hobbs was 9.9.
Well crap, how long have I been flying?  I transferred some fuel to the
main tank just to be sure I had plenty. (The fuel gauges work but are so
non-linear I haven't learned what any particular reading really means.)

Uneventful landing and I was sort of expecting it to be OK, i.e. I
wasn't as nervous as I was for the last two.  Now I've got something to
fix.  I got a good time for TO from the video camera and it turns out
the flight was exactly 1 hour.

I'm still seeing around 7500 rpm at TO, 100 mph and 1000 fpm climb.
Today I flew enough to find that I can run around 6500 to 6800 rpm and
keep the temps below 210 with IAS of 130 - 140 mph. And I can maintain
level flight at 100 IAS at about 5500-5800.  All at 8000 to 8500 MSL
I'm going to have to try my ground adjustable Warp Drive prop to see
what kind of performance I get running with a little more bite.

Bob W.



What is the weight of your airplane with you in it and
full of fuel? From that I can derive a guess on the HP.
Is your field elevation around 5000 feet?

Keep up the good work Bob. I love those pireps.
BTW I thing the pitch is too low on your warp drive.

-- 
Paul Lamar ...No rotor no motor.

Thanks Paul,  My total weight today was 1820 lbs.  I had about 35 gal
on board at liftoff.  Field elevation is 6200.  I saw the 1000 fpm
around 6700 to 7000 ft but won't guarantee the control inputs were
totally stable.  Like a lot of homebuilt, the BD-4 is very sensitive
to control inputs.

I don't have the Warp prop on right now.  I have an email in to the
company to see if I have a standard or HP model.  It was purchased
locally from a builder that didn't use it.  Interesting story about the
prop I'm using.  It's a custom prop made by a shop at the Moriarty
airport.  Solid carbon fiber two blade 68" dia X 78" pitch.  It was
made for a Lycoming 150 HP and started at 72" dia.  The Lycoming
couldn't get enough static rpm, so the prop was cut down 1/2" at a time
until they got to 68" and decided to abandon the prop.  They never got
over about 1900 static, and reducing the dia from 72 to 68 only made a
50 or 60 rpm difference.  Something peaked out at about 68 1/2" but I
don't remember what.  I'm turning static 6500/2.85 = 2280. The
advantage to me in using this prop is that it isn't costing me
anything unless I decide to keep it.  It isn't looking too good for
that right now.  I bought the Warp later because I got a pretty good
deal on it. I figured it would be good for ground testing if nothing
else. If it's the HP model, it should be good for flight too.

Bob W.

-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight:  11/23/2006 7:50AM - 1.7 Hours Total Time
Cables for your rotary installation - http://www.roblinphoto.com/shop/

Well you obviously have more HP at 6500 RPM than the
Lyc had at 1900 RPM. The Lyc 150 HP rating is probably around
2500 RPM or more. My wild ass guess is the Lyc was putting
out 114 HP at 1900 RPM. If your engine is 180 HP at 7500 RPM
than it should be about 156 at 6500. All wild ass guesses
and crude extrapolations. What is a BD4 supposed to do
performance wise with a 180 HP Lyc?

BTW as I recall the BD4 has an all flying tail with an anti servo tab.
If you increase the anti servo ratio that should make it
less sensitive. I got the BD4 plans around here someplace. If I
find them I will take a look. Are the ailerons sensitive too?
-- 
Paul Lamar ...No rotor no motor.

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