John,
No it’s not normal behavior for these AIRFRAMES.
It is, however, not at all unusual behavior for a new Lancair PILOT. You
mentioned that the second attempt showed an improvement. My totally uninformed,
no data, guess is that it had nothing to do with the added fuel. The third
attempt will probably be better still. It simply takes some getting used to. One
hint: once you’ve accelerated past about running speed keep your feet off the
brakes. There’s plenty of rudder control available with full power and just a
little speed. Trying to steer with brakes at speeds above 10-15 knots generally
results in the behavior that you described.
I don’t know what your experience with Lancairs
is but if you haven’t flown one before PLEASE get some guidance/instruction from
an experienced 235/320/360 pilot or instructor. As you all have heard me say a
million times, these airplanes are not difficult to fly but they are different.
Different enough that even extremely skilled and highly experienced pilots need
Lancair specific training.
Bill Harrelson
N6ZQ IV 550 hrs
formerly N5ZQ 320 2,200 hrs
Sent: Monday, May 05, 2014 7:17 AM
Subject: [LML] [LNC2] Fast taxi testing
This
morning I made several fast-taxi runs in my Lanciar 235/O-290-D2. The first few
runs were with empty wing tanks and it got real squirrely. The plane would veer
from side-to-side with a period of about 3 seconds and it was all I could do to
keep it on the runway. I got scared at about 50 KTs, pulled the power, and
applied the brakes heavily to keep from going into the weeds. I never could get
going fast enough to lift the nose wheel.
I taxied back to the hangar and
added 5 gallons of 100LL in each wing tank and repeated the test. The results
were much better but the side-to-side oscillation was still there and it was
easy to get into a P.I.O.
Is this normal behavior for the small Lancairs?
Could this be due to something in the oleo strut? (I don't have the centering
mod)...Tire pressure?...Dragging MLG brake?...Any other
ideas?
FWIW, I added a 5" ventral fin and extended the rudder 5" to avoid
just this sort of thing with the larger engine. Apparently, those mods don't
work at low speeds.
Help!