Steve,
For small deflections you can use: sin(3 deg) * (flap
chord)
My flap chord at the root is 10.75", so 0.56" -
Another option is a digital level.
The faired-in position is pretty accurate at -7 degrees. When
I calibrated my flap position transducer, I had to make a full size template
to locate 0 degrees. The fuselage fairing ended up right at -7.0, so it
is a good reference.
When measuring speeds greater that 120 KIAS, I recorded each point
for at least three minutes. I found that it took about 2 minutes to reach
a truly stabilized speed after a power or flap setting change. The
speed decay is so slow it isn't really detectable by starring at
the airspeed indicator. Imagine trying to see average needle
movement of 1kt/min. Fortunately the two minute settling time is very
consistent.
I think it would be quite valuable and educational to repeat
the same series to of tests on a small tail 320/360. I would be
more than happy to go over all the details with anyone interested in
volunteering. I think the biggest hurdle is mounting the alpha/beta
probe. I was able to grab onto the mounting provisions for my wingtip
lens with a fiberglass 'lens' to mount the probe. The internal transducers are relatively
simple.
Chris Zavatson
N91CZ
360std
From: steve
<n5276j@aol.com>
To:
lml@lancaironline.net
Sent:
Monday, September 30, 2013 5:59 AM
Subject: [LML] Re: Lancair 320/360
performance and stability
Chris, I'm going to re-just my flaps to -10 reflex and see
what happens. What would you guess the measurement is up from the trailing
edge of the faired in position?
Thanks
for all your work. Do you need a small tail 360 for more testing?
Steve Alderman N25SA
-----Original
Message-----
From: Chris Zavatson <chris_zavatson@yahoo.com>
To:
lml <lml@lancaironline.net>
Sent: Sun, Sep 29, 2013 8:54
pm
Subject: [LML] Re: Lancair 320/360 performance and stability
So I happened to be looking for something unrelated in the FB manual and
came across this on page 10-24:
"Lancair flaps are full electric actuated. They are designed to run
from +45 down to -10 up (reflex). Note that the 'faired in position' for
flaps is actually a -7 deg reflex position. ....."
My standard build manual is in storage so I could not compare. It
would appear the intent was to be able to go to -10 degrees after all.
Chris Zavatson
N91CZ
360std
Chris,
today I made a picture during Cruise with Autopilot at 7500ft with
following configuration:
770 kg 40l in header, 20l in each wing (80l total), 75kg and 83kg
for pilot and co.
Flap was on 7° reflex CG 26,20"
My design CG is 22,8 - 30,3 from firewall back,
horizontal was installed - 0.6°
So it looks like if I would add more reflex than 7°, I would need more
down elevator.
So the gain with the higher reflex would be lost with the down
elevator....
Christian