REFLECTOR: Nose Wheel Shimmy on Fixed Gear Velocity

[Donald Bates]

David's friction damper had enough friction to prevent a deflected wheel and pant from centering
 in the wind.  This indicates that the aerodynamic center of pressure of the profile planform is too
close to the pivot (shimmy) axis and the wheel pant couldn't generate enough restoring moment
to center the wheel. There needs to be enough profile area behind the pivot axis to increase the
aerodynamic restoring moment and overcome the sticktion friction in order to center the wheel. 

One method to add profile area behind the pivot axis could be to add a fin on top of the
pant that increases in height toward the rear of the pant so there is much more planform area
well behind the pivot axis.

It would help the wheel streamline in the wind (slipstream) and not be deflected at touch-down
and prevent the big kick back that a large deflection could give and help to eliminate that very
hard destructive shimmy. This problem is also prevalent on the RGs so in any case it is a good
idea to convert to the viscous damper to get the best shimmy prevention.

Don Bates
N14B SERG
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