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NOSE WHEEL SHIMMY
(From CP34, Page 9, October, 1982)
We have cautioned EZ pilots about nose gear shimmy damper
adjustment in the last two Canard Pushers, yet we still have EZs losing their nose wheels.
It is a fact that your nose wheel fork will fail if you experience shimmy on
landing or take off. It is also a fact, that if the friction damper is correctly
adjusted, you will not have shimmy at all. The nose wheel fork will not fail due to
a normal landing. It is very strong, the original fork has been grossly overloaded
to the point of failing the NG15A casting and/or the 1/8" aluminum plate on the
forward face of the NG15A casting. Yet the fork was not damaged. This has
occurred several times. We are satisfied that the fork will fail if it shimmies.
Therefore if you keep the friction damper adjusted and check it regularly, you will not
have this problem. Every time you extend the nose gear, just before you get
your EZ, hold the nose wheel clear of the ground and use your foot on the trailing edge of
the nose wheel tire to check the friction. You will soon get calibrated. You should have
to push or pull 3 to 5 lbs. to pivot the fork.
When taking off, try to rotate positively, hold it down until you have the proper speed, then rotate smoothly. Try to keep the nose wheel from touching back down or skipping, this is when shimmy is most likely, at the instant of a light touchdown. The same applies to landing. Hold the nose wheel off until you are traveling as slowly as possible. Then let the nose down and hold it down with forward stick. Do not let it skip. Avoid nose wheel touchdown at very high speed.
If you follow these simple steps you will minimize any chance of shimmy and therefore the chances of losing a nose wheel. The prototype Long-EZ still has the original thin wall fork and with over 680 hours, has never experienced any shinny. N26MS has almost 500 hours with probably more take off and landings than the prototype and it too has not had nose gear problems. Dick and Jeana have high time Long-EZ with over 700 hours and also have not had shimmy or nose wheel failures. There is a lesson here - get into the habit of pre-flighting your nose gear. Keep your friction damper correctly adjusted.