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Old March 22nd 09, 11:00 PM posted to rec.aviation.soaring
Rod Swallow
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Default Grob 109 wing pins

Dear Gilbert

I am a Grob 109b owner in Australia. Currently I am trying to assemble a
trolley to make wing folding easier as I want to be able to rig it on my
own. Do you have any suggestions?
Thanking you

Rod Swallow



At 16:13 07 February 2009, Gilbert Smith wrote:
In the UK we replace them on the G109B at 3000 hours irrespective,
together with a few other mods which come up at that time. The new
pins have a better taper, handy if you rig frequently as I do, and are
replaceable without the major surgery reuired on the first occasion.
- Colin.

"Bob Jenneson" wrote:

Hi,
I am seeking advise on the replacement of the wing pins fitted in

the

end of the spars on Grob 109 and 109B.
This also applies to the Grob Twin Astir.

A brief history.
These pins are welded to a plate that is glassed into the wing spar end


during manufacture. It was found out at a later time that some of these


assemblies were prone to cracking around the welds and required

replacement
if found to be cracked.
In Australia we are required to "ultrasonic " test these pins

every
500
hours ( AD 370 )
If tested 'OK' we keep flying.
We now have two aircraft that have 3000 hours each ( Life extension

time
)
and no cracks found.

Do we need to change the pins?

This is serious and expensive surgery and I am seeking advise as to how


other countries have dealt with this problem.
I understand that Australia in the only country that uses the ultrasonic


test.

Grob are happy to supply the new pin assemblies, but is it really

necessary
if the old ones have a 3000 hour safe history.

Any help appreciated, Bob.