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Message
After 6 long hard
months of body work, paint, polish, frustration, and hard hard work I finally
was able to again start flying a few hours on my Super ES N132BB. She is a
beautiful airplane. Right up until the point that the nose
gear entered into a violent shimmy and then collapsed. It started at
about 30 knots during the landing rollout. There was other traffic
following me in the pattern. PVU has a new tower and the controller
was requesting expedited departure of the runway. But nothing beyond
ordinary braking and deceleration was applied. I got it slowed to about 15
knots when the aft nose gear support brace broke at the weldments. The
gear strut folded backwards and the engine oil pan resting on the aftward
collapsed strut became the support for the airplane. It tracked
straight down the runway. There is no damage beyond the prop, engine,
engine mount, nose gear strut and front wheel pant. Not even the spinner
was touched but the 4 blade MT prop is nothing but stubs. It was not under power
and was rotating at about 750 rpm.
I had just completed
a very thorough condition / annual inspection. I had given particular
close attention to the nose gear and strut because of recent reports of nose
wheel shimmy. I had completely serviced the strut with fresh Belray 30 wt
fork oil, I had purged all of the old oil (50 hours old) by compressing the
strut several times with teh valve stem removed, pressurized the strut with
nitrogen, worked out all of the air by compressing the strut several times and
also turning it from right to left using the dual sheet metal and grease
sandwich method. All of the air had been purged. The strut was
sitting extended at 2.75 - 3.0 inches with the full weight of the engine,
prop, cowling, etc. I had put a lot of time into looking at the engine
mount and all of the attaching points of the nose gear. I had rechecked
all of the torque on all hardware. I had increased to max pressure 50 psi
on the nose tire.
I had made 7-8
landings since starting to fly the airplane again. All landings were very
light and "picture perfect". I had always held the nose wheel off until it
lowered itself and I continued to maintain full aft elevator during the
rollout. I don't know what was different for this roll out that set up the
shimmy as compared to the several other landings made Saturday and today.
There is not one thing that I can point to that created this
situation.
One thing is
certain, nose wheel shimmy is real and it causes landing gear
failure.
I had hoped to make
Oshkosh. But perhaps next year.
Bryan
N132BB Leaving 100%
to 80% and still building.
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