REFLECTOR: COLLAPSED NOSE GEAR

[Tom Martino]

Upon a thorough investigation of my plane, I discovered the reason for
the collapsed nose gear.  The "over-center" lock hyper extended causing
it to fail.  The reason it hyper extended is due to a missing aluminum
"stop".  Without the safety-stop provided by the bracket, the only thing
keeping the over-center lock in place was the hydraulic cylinder.
 
After 70 hours of flight and some hard landings, the over-center linkage
was continually pulling on the hydraulic cylinder rod when the nose
strut was down.  Any bumps exacerbated the problem.  Eventually the
hydraulic cylinder rod could not take the stress and it failed.  That
left the over-center mechanism with no support causing it to hyper
extend.
 
Why was the aluminum "stop" bracket not installed?  My bad.  A stupid
mistake.  It was originally there, then removed and not reinstalled.
 
Fortunately, the plane has only minor cosmetic damage.  However I will
need to replace the entire nose strut assembly ... including the
over-center lock, hydraulic cylinder and gas spring.  The episode will
allow me to do make the assembly better than before, with better access.
 
Thanks to those who offered ideas both publicly and privately.  
 
Tom
 
  
 
 
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