Glenn...as someone still in the throes of building, I feel it would presumptuous
to offer an opinion on how this situation evolved other than to note that the
AN960-10L washer serves a critical purpose between the sleeve and the stiffnut,
and that the profile of the stiffnut may suggest at first glance that a washer
is in place when in fact it is not.
On a previous post-flight inspection, unrelated to our Europas, I was utterly
astonished
to learn how quickly a bolt (once unconstrained) can back out from its
threaded receptacle just from the subtle vibrations of a VERY short flight...
Fred
A194
On Apr 8, 2013, at 5:04 AM, Glenn Rainey wrote:
> This is strange.
>
> Hopefully attached to this posting is a picture of the starboard outrigger
> mechanism
as we found it on preflight yesterday; ops were cancelled due wx, and
also due to uncertainties about this discovery.
>
> The stiffnut normally securing the rearward part of OR12 spring is only
> partially
threaded onto its bolt, and finger loose. The AN960-10L washer is missing,
and OR12 hangs from one end.
>
> An engineer in our group also inspected the locknut and found it satisfactory
on a new bolt. The original bolt awaits closer examination, however a new fresh
nut was secure when attached to it.
>
> These parts would potentially be missing in any accident investigation search.
>
> I cannot understand how a stiffnut can come undone in this installation. This
assembly was fine when inspected one week earlier prior to a test flight, during
which the gear needed cycling once to achieve an outrigger- retracted green
light indication. It was not examined post flight then, but the aircraft was
subsequently unattended.
>
> If we hypothesize that perhaps the washer was missing from the original
> assembly,
methinks unlikely, then could the thing manage to self-disassemble in the
course of one short flight with two gear cycles?
>
> I can think of one _possible explanation for this which is a worrying one, but
perhaps other folks have ideas? No maintenance was needed or carried out on
this part of the airframe in recent time.
>
> Glenn Rainey / Martin Burns
> G-OJHL
> Classic monowheel
> Scotland
>
> * my second attempt to post, perhaps the image is a problem. Can anyone help
with image posting / hosting?<Image1.jpg>
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