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<< Lancair Builders' Mail List >>
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I have flown long cross country legs in two pressurized IVs, and both had
the elevator counterweights stick up above the stabilizer skin about 1/4
inch in cruise. I think they all do it, at least at the aft C of G
position. Same is true for our Cessna TR-182. The position will vary
depending on speed and center of gravity.
I would be less concerned about drag than ICING. If you square the leading
edge of the counterweight (many do for the "tight fit" look) you have a very
effective ice catcher that will the first area to collect ice on the
airframe, long before you see ice elsewhere. Even in light icing
conditions, ice collects on the counterweight leading edge and quickly welds
it to the stabilizer. It has happened several times on several aircraft
that I am aware of, and so is probably a common occurrence for those that
fly IMC above the freezing level (which is probably everyone). The
subsequent events are not pretty as you lose elevator authority and must
control attitude with power. And if you try to thump the stick to break off
the ice, plan on negative g's (in IMC) if you succeed. A friend has been
there and done that several times.
The prudent thing to do is round off the leading edge of the counterweight
so that IF it extends a bit higher than the stabilizer, the leading edge is
still tucked in behind the stabilizer tip and so will not collect ice except
possibly farther back on the counterweight. Yes, you do lose a bit of
counterweight volume at the tip of the counterweight. Yes you will need a
bit more lead as a consequence. Yes you will be much safer if you do so.
This problem is well known, there have been several incidents, and yet
builders STILL build squared leading edges on the counterweights "because it
looks pretty." All I can say is it is DUMB, DUMB, DUMB on an IFR airplane.
Fred Moreno, who has fallen out of the sky covered with ice (in a turbo 182
RG) and will never forget it.
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LML website: http://www.olsusa.com/Users/Mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.
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