Re: First the AI, then the DG, then...?

Jay Honeck wrote:
> > > Again, there is no logic to this -- but what else is new?
<snip>

Jay,

I joined this thread a bit late...after my local server flushed the 
original message, but I believe your original question was "what could 
cause premature gyro failure"?

In my experience, two things:

1) If it fails within a few hours of being new, that's typically because 
of manufacturing, long-term storage, or shipping damage -- all of which 
can cause the bearings to "flat spot".  Apparently the bearings are 
*that* soft.

2) If it fails after a few hundred (as opposed to a few thousand) hours, 
improper mounting or excessive vibration is usually the culprit.  The 
problem is most severe in aircraft whose panels aren't shock mounted AND 
when those same aircraft don't have their props properly (dynamically) 
balanced.

Our gyros were so damn expensive that when we had our panel apart last 
time I had the shop replace the mounts.  Not only does the panel NOT sag 
like it used to, but as we encounter various (normal) harmonics in our 
particular engine/prop combination, the shock-mounted instruments simply 
don't shake like some of the other fixed mounted units (fuel gauges, etc).

I forget if your airplane has a fixed or shock-mounted panel, but if 
it's shock mounted, I'd recommend replacing the shock mounts and getting 
the prop redressed / painted, then dynamically balanced for good measure.

HTH,

-Doug

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Doug Vetter, CFIMEIA
[EMAIL PROTECTED]
http://www.dvcfi.com
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