Colyn,
At an empty weight of 2290#, the CG of my IV-P (with air conditioning)
is almost two inches aft of the most forward allowable. Having set a MGWt of
3600#, I run out of CG before I can actually load to this weight with any
reasonable configuration. My elevator trims up below 160 KIAS, approximately neutral
at 160 KIAS, and goes progressively nose-down as the IAS increases. My
translation is that the tail plane needs to generate just a bit more (down)
lift to be able to fly with the stab in a neutral position. Changing the incidence
of the tail plane could move it toward neutral in high speed cruise, but would
adversely affect the slow speed (TO & land) trim and handling.
BTW, my trim setting for TO and normal landing is the identical.
I rarely need to adjust the trim in preparation for TO—unless someone
bumps the trim switch while trying to arrange their “stuff” in the
right seat…
Bob
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case at earthlink
Sent: Monday, February 23, 2009 9:51 PM
To: lml@lancaironline.net
Subject: [LML] IVP hstab incidence (was 360 in a small-tail LNC2)
My
IVP is extremely forward CG. not out the front of the envelope, but more
forward than any other IVP I know.
and
yet, at cruise I am trimmed several dots down from neutral, which would mean
considerable elevator deflection.
I'm
wondering if any IVP out there has the hstab incidence set up so that the
elevator is neutral at cruise?