Grayhawk,
Please note that he
said;
“The elevator
bob weight was below the horizontal (elevator up, nose pitch
up) with flaps all the way up.”
That implies nose up trim not down trim.
Regards,
Bill Hannahan
--- On Mon,
2/23/09, Sky2high@aol.com <Sky2high@aol.com>
wrote:
From:
Sky2high@aol.com <Sky2high@aol.com> Subject: [LML] Re: 360
in a small-tail LNC2? To: lml@lancaironline.net Date: Monday,
February 23, 2009, 7:51 PM
Craig,
Uh, I believe you are flying high in the ASI yellow arc
all the time. That is quite beyond the max cruise design
speed of about 180 KIAS and should require the extra trim you
mention.
BTW, mine runs out of down trim at 200 KIAS - so I push on the
stick a bit when racing. I suppose I could add a bungee cord
from the firewall to the stick for added trim. Gee, I run out
of left rudder trim also.
Anyone that put an engine with greater than the design HP
should expect to consider, uh, trim adjustments since the
design envelope has been pushed beyond standard
limits.........
Grayhawk
In a message dated 2/23/2009 5:17:00 P.M. Central Standard
Time, craig@skybolt.net writes:
Hi Larry,
I think you are right about the incidence
being wrong in a lot of these airplanes. Mine will run
out of down trim over 210 kts. A quick look back and I
can see the elevator counterbalance sticking up about 3/8
inch. My CG is perfectly to spec but at 210+ it doesn't
seem to matter how the airplane is loaded. It still needs
gobs of down trim. The problem is the faster the airplane
goes the more lift the wing wants to create. So to keep
the airplane flying level you have to reduce the angle of
attack, that means down trim. A full flying horizontal
stab would be the most efficient way around this.
Craig Schulze Lancair 320 small
tail.
-----Original Message----- From: LHenney
[mailto:LHenney@charter.net] Sent: Sunday, February 22, 2009
2:36 PM To: lml@lancaironline.net Subject: FW: 360 in a
small-tail LNC2?
Tom,
I had occasion to visit my CG
limits for a son's science project. Similarly I was
assessing elevator bob weight position relative to the horizontal
tail at race speeds and comparing airspeed data.
In my aircraft, your premise would be wrong. That
is, I have to move the CG forward to flatten out the elevators
to the horizontal tail (which also increases speed (yes it's
hard to believe)). As opposed to changing CG, one might
verify horizontal tail incidence. Or more precisely all
Lancair 320/ 360 I've flown with have this same affect (bob
weights a little high at least minimally).
Regarding
your CG comments, serious pursuit of empty CG before
any additional flight would be my recommendation (imho). The
phrase " way to far forward I think" has me
squirming.
Larry Henney
PS: In my estimation,
several 320/ 360 builders took the tail plane template and
transferred it to an incidence guide. The subsequent mistake
was mounting one's smart level atop the guide and setting the
tail plane at the requisite 1/4 to 1/2 degree nose down.
The mistake is missing the fact that the incidence guide off
the blue print was already 1/2 degree nose down. Thus reading 0
deg on the smart level should have had the tail at the
1/2 degree nose down angle. Many are actually 1 deg nose
down. This is not a problem. It just increases
stability and costs 2-3 kts.
Just my 2
cents.
-----Original Message----- From: Tom
McNerney [mailto:dudewanarace@yahoo.com] Sent: Friday,
February 20, 2009 12:51 PM To:
lml@lancaironline.net Subject: RE:360 in a small-tail
LNC2?
Works great. I have a 400! I'm sure
the rest of small tail group would agree. Might have to
move your center of gravity back. (I need to) Only thing
I can say is that slow flight with full flaps isn't the
most comfortable, but now that I am aware of how
it handles, doesn't bother me a bit. My CG is way to
far forward I think, so that probably makes the slow flight a
little different.
On a side note.. I turned
around and looked at the tail the other day while
indicating 200KTS. I could see the elevator counter weight,
or almost all of it. I didn't expect to see that at
200. Maybe 100.. haha This leads me to
believe that I have a forward center of gravity. The big
engine would explain that. Once I get the
plane on some scales, the only thing I can think of is to
move the battery. My battery is behind the
passenger seat.
Has anyone mounted a battery behind the
baggage compartment?
Advice?
Thanks Tom www.N54SG.com
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