Just got the plane back into its home hangar where another tear down and rebuild will commence Monday.  The fix in Colorado was the best possible under extreme circumstances but sufficient for safe operation over America's mountains.

The mount completely broke (tube mostly separated) in 4 places.  The cross tube above the strut broke on both ends and fell out when I removed the bottom cowl.  Both diagonal tubes that atch at the 

cross tube and aft engine mounts broke at the aft engine mount ring.  My brother will send all failed parts to Lancair when he returns from his delayed vacation for analysis and I will pass those results along when available.  Pam took some pix in the dark hangar, so if any are informative I will pass one along soon.

I think the strut/mount discussion is of the chicken/egg variety.  Yea I might have had a cracked mount and didn't catch it during the Jan annual, or I might have had internal damage to the strut that went undetected.  However, I don't know how to check the internal health of the strut, and if a cowl removal every 6 mos/50 hours is not a sufficient mount inspection internal during normal operations, well I guess there is a design problem that needs some attention. 

paul, N94PT

 

I have had an intermittant, "light" shimmy on rollout on several
landings.  These have been separated by several landings where there was
no shimmy.  The ESCO strut was rebuilt by Lancair 8 months ago due to an
towing damage (too small a turning radius).  A stronger strut shaft and
wider turning stops were installed.  Since then I have serviced the
strut, changed and balanced the tire, checked the bearing preload and
tried different tire pressures.  (I've also replaced the disks thinking
the shimmy was brake related at one time.)  The shimmy seems to be
fixed...only to return within a few flights.  I have the new design nose
strut on order from Lancair.

Now, for the question.  Do you have photos of the failure locations on
your engine mount.  I have decowled and examined the engine mount
numerous times after a shimmy event to look for any fatigue cracks and
have found none.  But I will redouble my inspection when I replace the
strut if you can point me to all the right places.  Can you enlighten me?

Barry Knotts
LIV-P, Conti TSIO-550, N4XE
Perrysburg, Ohio

ptackabury@aol.com wrote:
> How 'bout something re: LIV rather than personal etiquette, scripture,
> other's misfortunes and the Hanoi Hilton. As the keenly aware out
> there may remember, I have a LIV that was, up until 23 Jun a screaming
> joy with no problems. And then while landing in Fort Morgan, CO to
> visit my brother, I had a nose wheel shimmy that destroyed the motor
> mount (broken in at least 4 places), strut, fork, trailing links and
> over center gas spring, along with associated hardware and the bottom
> cowling. The only good news was the strut didn't fold, although I
> still do not know how it remained upright. Michelle and Kim at Lancair
> were fabulous and had replacement hardware to me on Friday the 26th.
> My brother and I have been rebuilding ever since. We have now replaced
> the main parts and are rigging the engine to fit the cowling in hopes
> of a flight back to CA (home/Chino) this weekend where the final redo
> will take place.
> Some observations: I think the strut was OK--it was about 6 years old
> but looked fine. I now have the new strut Lancair is building so maybe
> something was wrong with the old ECCO model. The engine mount just
> disintegrated so maybe it had some cracks i missed during the Jan
> annual--certainly that will be a major focus in all future cowl
> removals. So learn what you will from this msg--question as you wish
> and I will offer what I can. But be assured this incident had nothing
> to do with my dual LSE ignition system...
> paul, N94PT, reluctant rebuilder
>
> --
> For archives and unsub
> http://mail.lancaironline.net:81/lists/lml/List.html
>


--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html