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As the "knowledgeable" Doug Brunner himself I would like to comment on the
origins of this "urban legend".
During the build of my Legacy I put on a variety of different "speed mods"
including:
. Ron Jones wing root fairings
. Ron Jones horiz. stab fairings
. Chiavetta fuselage side fairings
. Mark Mahnke custom exhaust tunnels
. Mahnke/Brunner custom made flap gap seals
. Ron Jones flap hinge fairings - these are relatively simple fairings
that just streamline the base of the hinges.
I also went to the trouble of having a template of the leading edge made to
make sure that the airfoil shape was correct.
In addition, I have a Barrett 10:1 compression IO-550 which was dynoed at
325 hp.
After I put on each "speed mod", I would proudly proclaim - "another 5
knots".
In reality, I have NO IDEA how much each of these mods added to my speed.
The right way to do a speed mod is to fly the plane before then put on the
mod and compare - and because of the practicalities of the build process, it
was not convenient to do it that way - so I didn't.
I will say that when I first flew the plane (before I put on Therm-X de-ice)
the plane did about 247 ktas at 9,000 ft. - which is pretty good.
Clark Baker just finished his Legacy, and from what he tells me it is a
"screamer". He was a "fanatic" about his weight and made a number of speed
mods, including some flap hinge fairings. His plane is faster (and
definitely lighter) than mine. Suggest you contact him for info on his flap
hinge fairings.
D. Brunner
N241DB - approx 600 hrs.
-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Paul
Miller
Sent: Friday, January 18, 2013 3:34 PM
To: lml@lancaironline.net
Subject: [LML] Re: EVO flap hinge fairing
Brunner just reported he got another 5 knots but refuses to disclose the
source of the improvement. He has now left for Baltimore today and I am
unable to inspect the Legacy.
OK, I apologize. It will now be known as a "thingy" hanging off the bottom
of the Evolution, the purpose of which may, or may not, be to smooth the
airflow and reduce drag. I may place an order for a test "thingy", tape it
on and report on the results.
Paul
Legacy sans thingy
On 2013-01-18, at 3:22 PM, Dan Ballin <dballin@gmail.com> wrote:
Really. Come on give him a break. The evo hinge is sculpted to be aerodynamic or at least good looking. You can get or make fairings for the legacy hinges. I think Ron Jones used to make some. Like most everything else on our planes, and I quote from the knowledgeable Doug Brunner, it will increase your TAS 5 kts. Just kidding I don't think anyone has really tested it. I think if you like the looks, put them on.
Dan Ballin
N386DM LEG2
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