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Grayhawk,
One thing the ES has that most other Lancairs don't is a
nosegear fairing which serves as an inverted stovepipe for heated air coming out
of the cowl. This tends to considerably heat up the strut, even on cold
days. One unwanted side effect of this is the warming of the
fork oil in the strut which lessens the viscosity and can make it more prone to
shimmy.
Unless Jim's flight was very short, I think it's unlikely a
cold strut was a factor.
Skip Slater
N540ES
----- Original Message -----
Sent: Tuesday, December 09, 2008 5:43
AM
Subject: [LML] Re: Nose tire
mystery
Jim,
Bear me out. If I remember right, you would have been flying an ES
(Gear floxed into the extended position).
When you took off, the low pressure in the strut never allowed the strut
to fully extend (cold). It might be possible that you immediately entered a
crab on liftoff and the centering mechanism never straightened it
out. On the other hand, assuming that the strut never was fully
extended, while the x-wind at ground level was a mere 7 kts, it may have been
more on the long straight in (?) approach and perhaps you were
flying in a right crab while the nose wheel pant was aerodynamically
flying the line to the runway. When you touched down, the fluid/seal
held the nose wheel frozen, pointed to the left. It took some force to
break it free.
The first time out in cold weather can affect tubeless tire leaks,
hydraulic seal anomalies, etc. These usually go away after the first,
uh, gremlin strike. They also go away on flights to the far south.
Grayhawk
Seeking explanations for the unexplainable.
In a message dated 12/8/2008 1:08:42 P.M. Central Standard Time,
marv@lancair.net writes:
Posted for "Jim Scales"
<joscales98@hotmail.com>:
Need some help figuring this
one out.
Flew a couple of days ago and had an interesting
experience on landing. I
have attached some pictures to help
explain what happened.
Landed with slight RH
crosswind. Touch down speed was about 75. Everything
looked
fine, right tire touched down, left tire touched down, nose touched
down
and plane immediately pulled to left.
Figured I must have
landed with some brake pressure on left pedal. Released
left
pedal, made no difference, plane pulling hard to left while main tires
begin to skid.
Begin to apply right rudder and
brake. Helped but not enough. Locked up
right
brake, plane began to swerve back to the right. Main tires
started
skidding in other direction and plane started to rotate to the
right.
Released right brake as the nose came back toward
alignment with center of
runway. Plane straightened out, I
slowed down, turned off, taxied back to
hanger with no further problems
(other that that shorts issue we all talk
about).
Conditions at the time of the
flight: +2C on ground, -5C at level I was
flying for about 20
minutes prior to the landing, 7kt wind from 320 while I
was landing on
27.
During preflight I had noticed tires needed some air
but not any different
than some other flights. Cold weather
had come in since last flight and tires
lost some
pressure.
I also noticed the nose strut was down
some. The normal 3-1/2 spacing was
about
2-1/2. Again not that unusual. Have flown with this
spacing on a few
occasions with no problem.
When I
checked everything after the flight I found the main tires to be at 45
pounds, the nose tire at 25 and the spacing on the strut at about
1-3/4. No
flat spots on any of the tires. I was
puzzled by the height reduction on the
strut.
The
strut was rebuilt in October. This is the first really cold day I
had
flown it since then.
I have some thoughts about
what the problem could be/have been. I would
really like to hear what
you folks have to say.
I serviced the tires and inflated
the strut. I have flown it twice since
then with four
landings and no problems.
Thanks in advance for the
help. I must say that ten years of racing stock
cars on dirt
tracks made a big difference in how this turned out. I was
fortunate.
I am very interested in finding out what
happened.
Jim
Scales
Note: The pictures may not load in
sequence (proper sequence is 02, 17, 39,
19, 19, 40, 18, 10) so you
should look at them from the point of view of the
landing sequence and
roll out. You will see the lines as the nose tire
touches
down on the center line then progresses to the left. You will see
the
main tires start to skid then the nose tire appear to straighten
out. The
next will be the RH brake locking and the plane
coming back toward the
center.
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