Hi Chris,
thank you for sharing this interesting reports.
During my flight testing I used accidentally 14° of reflex
instead of 7°. I don't have data what the difference in speed
between 7° and 14° was.
As far as I remember there was a similar difference between
0° and 7° as yours.
During building I installed a longer flap actuator (200mm)
to get the full travel. When my testflying was finished, I
installed a phenolic block
to get a hard stop at 7°
I could easily get more then 7° by grinding a bit off....
But then the flap would stick out of the fuselage fairing
and this might create more drag... What do you think about
this?
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The 3,5" increase from CofG sounds good.
I have a long engine mount and a heavy engine (IO390), so I
extended my mac from 15° to 11° as recommended from Lancair
(issue 1/99 page 8)
Having the CofG more forward works nice. My trimtab is
smaller as the plans say. So I needed to install the trimspring
as well in the elevator pushtube
to preload the system. On ground my elevator stays level due
to the spring.
I still have my mtow at 765kg as my inspector was a bit
"unflexible". Now I found a way to increase to the factory
tested 810kg. I use a 2. cathegory (Utility)
with 3,6g instead of 4,4g. I tried flying with 850kg and
never had a problem with changing in flight characteristics. I
even don't reach the original rear CofG
when flying overloaded.
I the US the builder can set its own mtow, but here in europe
it has to be tested in all ways...
I passed my load test at 4,4g with 2350kg on the wings.
In your opinion, what could be the max mtow for me when I
stay in the 3,6g cathegory without doing a new load test. If I
could get 840kg I would be more
than happy. I just have no clue to make some basic
calculation to convince my inspector....
Doing a gross weight increase means payinng money to get a
test permission and doing the testflying again including:
takoff and landingdistance, climb performance and noise test.
The reason I want to do this, we get more and more ramp
checks. I they get me flying 50kg overloaded, I have to throw my
copilot out of the plane. My father
will not be happy going back by train ;-)
regards,
Christian
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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.
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.
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.
Chris Zavatson
N91CZ
360std
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