Frans=0AThe pip pin on the port side is there to prevent the starboard spar
from twisting away from the =0Aport spar under high load. The starboard si
de has no need of retention because the overlapping =0Aspar provides that f
unction.=0AStrictly speaking the bush in the seat back bulkhead is of no va
lue, in fact it increases the load on the spars.=0ABe better without it as
per the motor glider. (but DYOR)=0AGraham=0A=0A=0A=0A=0A___________________
_____________=0A From: Frans Veldman <frans@privatepilots.nl>=0ATo: europa-
list@matronics.com =0ASent: Friday, 7 June 2013, 9:07=0ASubject: Re: Europa
s Veldman <frans@privatepilots.nl>=0A=0AOn 06/07/2013 09:40 AM, Tony Rensha
w wrote:=0A=0A>- Talking about pip pins, does anyone see any merit in usi
ng two of the Port pip pins, another for the Std spar too?=0A=0AIf I recall
correctly, there was some technical reason why both pip pins=0Aare differe
nt. I forgot the details, but this discussion has been held=0Abefore and so
meone with insight argued why using a pip pin on the=0Astarboard side was n
ot such a good idea. It had something to do with the=0Adifferent arrangemen
t and thus different torsional loads on the=0Astarboard side because the sp
ars overlay "the other way around". The pin=0Ahad to be longer there to all
ow some movement, and because it needs to=0Ahave some play a pip pin can no
t be used (unless you make it longer than=0Ait should be but then you need
an additional retaining mechanism which=0Aof course negates the whole idea
of using a pip pin in the first place.)=0A=0AAlthough I have modified my ai
rcraft quite a lot, this is an area where=0AI am shy to deviate from the bu
ild plan, as it is one of the most=0Acritical structural area's. As all of
the other pins are pip pins my bet=0Ais that there must have been a reason
why to use a different arrangement=0Aon this specific pin. Surely it can't
be because it was cheaper or so,=0Aor the designer was short of one pip pin
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