However, just before fitting on the fuselage top, I took a last-minute
test of stab travel and found that in intervening months the range of travel
had reduced for some reason - and I got but 2.8deg nosedown and 11.6deg
Noseup travel! The trim travel works well, but the stab itself has reduced .
As well, I found the counterweight travel did not allow full noseup
travel, and I had not cut the trim slots long enough to permit full travel.
I lengthened the slots 1/8inch and the slot problem receded.
It was obvious I had failed to centre the TP18A swivelling rear end of
the counterweight arm to allow the arm to descend slightly into a happier
area, so I removed the two AN-3 bolts at the back and swivelled the TP18A
four turns shorter [1/8"]. Too much!
So I calculated the ratios of TP18A turns (32thread) to front end travel
of the counterweight and degrees of stab travel. At 2" +/- between aft bolts
and 30" length of applicable c/w arm I figured one turn [1/32" travel] of
TP18A equalled 1/2" change of countertweight position, and THAT equalled
2deg of stab position.
I'm wondering if anyone else ran into this condition, and whether my
calcs gibe with another's. If all is well, I will increase the travel of the
big pitch push rod to permit a greater range of stab travel [12deg to -4deg
in the book].
Any comments gratefully received.
Cheers, Ferg
A064
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