Like Bryan and Bob Harrison, I too found an excellent bond between rib and TP6
and agree with Bryan's point about feedback - here's some more which might help
others:
1. I agree with the guidance in mod 73 not to use power tools - I used hand
tools
and was glad I did, the foam is easily damaged.
2. Having had (I thought) almost 3/8" play at the tailplane trailing edge, I
intended to do mod 62 at the same time as mod 73. Having extracted the torque
tube from the fuselage, I find that the pins are reasonably tight and there is
significantly less TP12 to TP4 play than first thought. Investigation shows that
there is some wear between the TP11s and TP12s which contributes to the play
observed on the aircraft. After 440 hours, TP11 appears to be hardly worn
but there is a visible track worn into TP12 and some eccentricity (a bit like
its owner?). I have seen the same wear pattern on other online photographs of
TP12s - so I'm not alone! Since Mod 62 might not lead to a significant
improvement,
I'm tending towards not doing it until there is more wear - to avoid risking
ending up with the a similar degree of play and nowhere else to go (apart
---From Bob's clamp mod maybe). Presumably TP11 to TP12 wear is not as critical
as TP12 to TP4 - assuming good mass balance? Which
leads to the next point:
3. While the tailplanes and torque tube were out of the aircraft I decided to
do a check of the mass balance and was surprised to find the assembly 78g too
heavy at the weight end. I genuinely thought I had achieved a good re-balance
in situ after mod 70 but the friction in the control system was enough to mask
the imbalance. How many more Europas are like this and might it have contributed
to the accident?
Since correct mass balance is so critical and removal of the torque tube
(albeit
a pain) takes less than a day's work, it might be worth doing this at the
same time as mod 73 - giving the advantage of peace of mind and also being able
to use your own torque tube for a better layup than wrapping tape around plastic
pipe as some have suggested?
Hope this helps!
Roger Mills
Roger Mills
07921140616
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