Scott,

Are you able to provide a supplier for the material used for the gap
seals? Any notes about the installation? An engineer from Lo Presti
came across my airplane on the ramp one day at a fuel stop and was
crawling over it. "Boy, not much left to do on this thing!"  The only
thing he mentioned was extending the ram air inlet to be much closer
to the prop to maximize efficiency and the installation of gap seals.

I do enough long trips that 6-8kias would be of interest to me,
especially since I recently managed to hit headwinds over the course
of 3 days of flying, even though I flew in all directions in those 3
degs (nuts, right?) Every day brought a new and exciting headwind.
'Doh!

Keith

On Sun, Sep 15, 2013 at 3:26 PM, <Sky2high@aol.com> wrote:

Chris,
 
Great research.
 
In my small tailed 320, increased flap reflex experimentation did
not result in increased top end speed.  The nose up pitch was
increased, requiring increased nose down trim - probably resulting
in greater empennage drag negating any reduction in drag from the
greater reflex.  Of course, we would have to discuss the angle of
incidence of the small tail and its relationship to the elevator
correcting for nose down pitching ( my incidence was at -.9
degrees).
 
By moving weights forward and aft in the same flight, forward CG
was better for maximizing speed - unlike some aircraft that see max
speed when the CG is at the neutral point, probably a consequence of
more standard wing/tail design that saw drag from wing/horizontal
+/- lift factors more balanced and minimized.
 
For me, the biggest gain in speed came from adding $140 worth
of gap seals to both sides of all control surface and the flaps
(remember Greenameyer made his flaps part of the wing in his very
fast Reno Legacy - he didn't need no stink'n flaps).  I believe
that I lost no speed when I removed the upper seals from the flaps
last year. The seals were curved Mylar seals often obtainable for
gliders.  The gain was from 6 to 8 KIAS, depending.  Controls were
more responsive and the wee rudder was effective about 5 KIAS
sooner.
 
I didn't follow up on a cockpit controlled diffuser for managing
cooing drag as I saw about 7" H2O upper to lower cowl at about 135
KIAS (climb speed), but 13" at 200 KIAS and such pressure was not
necessary as the engine ran cool there.
 
I found the small tail had enough control - I only wanted my little
engine to pull everything along as quickly as possible.
 
Scott Krueger
 

In a message dated 9/13/2013 7:32:54 A.M. Central Daylight Time,
chris_zavatson@yahoo.com writes:

N91CZ has been a flying laboratory for most of this year.  Below
are links to three reports that may be of interest to the Lancair
community, in particular 320/360 flyers.
 
The first takes a look at the effect flap position has on total
aircraft drag using the NLF(1)-0215.  The numbers are quite
impressive in terms of drag coefficients.  In the end, it looks
like we could benefit from a little more reflex beyond -7
degrees.
http://n91cz.com/Performance/Cruise_Flap_Report.pdf [1]
 
The second report looks at the neutral point differences and
static margins of the small and large tail 320/360 models.  A
large portion of the document is a tutorial of sorts on
longitudinal stability.  It deals only with static stability, but
is a good lead-in to the third report.
http://n91cz.com/Stability/Lancair360_Static_Stability.pdf [2]
 
The third report looks at the stability of the 360 MKII in much
greater detail.  It include dynamic stability in both cruise and
landing configurations, as well as, stick force gradients and
elevator effectiveness all the way down to stall speed.

http://n91cz.com/Stability/Lancair360_Stability_and_Control_Evaluation.pdf

[3]
 
 
Chris Zavatson
N91CZ
360std
http://www.n91cz.net/ [4]

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Links:
------
[1] http://n91cz.com/Performance/Cruise_Flap_Report.pdf
[2] http://n91cz.com/Stability/Lancair360_Static_Stability.pdf
[3] http://n91cz.com/Stability/Lancair360_Stability_and_Control_Evaluation.pdf
[4] http://www.n91cz.net/
[5] http://mail.lancaironline.net:81/lists/lml/List.html