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Posted for "Mark Ravinski" <mjrav@comcast.net>:
Bob,
Seven years ago, when I started flying the 360 small tail, I had a similar
experience. The pitch instability is very frightening when it is unexpected.
It is similar to the "pilot induced oscillation" I experienced flying T-38's
in the service. That was caused by a hydraulic glitch in the pitch
controls.
I don't think a spin entry is necessarily a big concern. My rudder has
always been completely effective at preventing a spin even in a full stall
(at altitude).
My battery is in the passenger foot well area and was moved there from it's
initial location behind the seat.
If you have a fixed pitch prop, you might consider upgrading to constant
speed sometime. The extra weight in the nose and takeoff performance
improvement will help a lot.
I found that what helps the most is more airspeed. Once I get to 140 or so
there is not problem. Delay rotation a little, and climb at a low angle. I
find that the half flaps used for takeoff add a little stability and leave
them down until a little later, then raise them a little at a time.
For landing, keep a little more airspeed until you get right down close.
It's easy to land hard when you're heavy.
Aft CG is the limiting factor at heavy gross weight but you can get the
opposite problem too. When I'm solo and light weight, if I have most of the
fuel in the saddle tank the elevator runs out of travel in the flare and the
landing is not very delicate.
These limitations really tell us that the planes are incredibly well
designed and give us the absolute maximum performance and flexibility for
their size.
We, as pilots, have to do our part.
I used to have to cut the nuts off but now Champion has the "-1" that just
barely makes it.
Mark Ravinski
N360KB 1283 hrs
----- Original Message -----
From: "bob mackey" <nospam@pure-flight.com>
Subject: [LML] CG and Gross Weight [LNC2]
103MD is a Lancair 235 with small tail, and an O-320 on a short
engine mount. Fuel is in the nose, and in the outer wing leading
edges.
A few days ago, I took off with a load of just under 1600 lbs,
and with the CG near its aft limit.
....snip....
The takeoff roll accelleration was about what I expected for the
weight, but rotation was sluggish. We used most of the 3100' runway.
When the aircraft did rotate, it showed a definite tendency towards
over-rotation. Right away, it felt to me like the CG was too far aft.
Pitch was slightly divergent and had to be constantly corrected to
maintain a stable airspeed. At first I was too busy to raise the
gear, then I chose to leave the landing gear down to keep the CG
from moving any further aft.
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