Graham Singleton's tip for unsticking a stuck tailplane worked a treat -
thank you Graham. You put a close-fitting bar through the pip-pin hole
for the other tailplane and while tapping outwards gently with a heavy
hammer pull on the stuck tailplane. It only moves about 5 thou at a
time initially, but it moves and eventually is free. But here is the
lesson I learnt. Although I had greased the torque tube when I fitted
it last, the two close-fitting sleeves that it passes through wipe most
of the grease off and the outboard end has had the most wiping. That
was where the corrosion was, and I think it had got into the pip-pin
hole from the botton as there was some corrosion on the pip-pin. In
future before fitting I will put grease into the outboard sleeve through
the pip-pin hole and spread it around the inside of the sleeve with a
long stick through the torque tube hole.
My other problem with stiff ailerons is definitely caused by swelling of
the tufnol bushes. Tufnol is cotton fabric in layers impregnated with
phenolic resin. The end-grain is what is visible when looking down on
the bush, and being cotton which is exposed it is not surprising if the
cotton absorbs some moisture. The absorption rate is not great
(according to the specification), but it is not zero.
Frank
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