I did Mod 62 and it seemed a big improvement (all holes drilled and
reamed in a machine shop). 120 flying hours later it developed "a
tad" of slop on one side. I have loctited that side (therefore could
still remove the torque tube since loctite is on one side only). Is
the idea of the AN bolt option that it clamps the two parts together?
Is this a PFA approved mod?
Willie
> Hi all,
>
> The half inch play tolerance as specified by the factory means
> that, in a more than one degree range, the tailplanes are not
> balanced at all. This is a possible cause for flutter. I consider
> that any play in the chain between the mass balance arm and the
> tailplanes is unacceptable: that means zero play between TP4 and
> TP9 and zero play between TP 4 and TP12. The factory solution is
> Mod 62: replacement of the =BC=94 pins by 3/8=94 pins. This mod is
known
> to only delay, not eliminate, the problem. As far as I know, there
> are 3 solutions which have been implemented successfully by builders:
> - gluing TP9 and TP12 to TP4
> - replace the straight pins TP14C and TP14D by AN486 taper
> pins
> - replace the straight pins TP14C and TP14D by AN bolts
> As some builders have mentioned in this forum in the past, all
> these solutions have their own inconveniences and must be
> implemented carefully, but I believe these inconveniences are far
> outweighed by the safety of a fully balanced tailplane in all
> conditions.
> Regards
>
> Remi Guerner
> F-PGKL, XS S/N395 monowheel, 912S, Airmaster, 482 hours
>
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