I noticed in Daves RV6 when flying with the auto pilot
on and maybe with it off the tail would wag from side
to side. If you put your feet on the pedals and held
the rudder fixed the oscillations went away.

My C182 does not do that.


Paul Lamar



Paul,

I too have noticed the "tail wag" when riding in various RV's.  It is one
reason why I didn't choose to build an RV.  My Lancair doesn't do that,
unless there is a lot of turbulent air, but once back in smooth air, it
settles back down.

Mark S.


Which is exactly why I added a six-inch ventral fin on my Lancair ES.  Now
there is no fish-tailing even in choppy air.

Weight and speed considerations have led many kitplane manufacturers to get
by with smaller tail feathers than otherwise optimal.  When Lancair
introduced the ES, they used the same Lancair IV molds for the vertical
stabilizer, while significantly enlarging the wing and horizontal stab.
But
when they decided to certify a version of the ES (Columbia and hence Cessna
Corvalis), one of their first changes was to significantly increase the
size
of the vertical stabilizer.  Even then they had to add a ventral fin to the
Columbia 400 to meet high altitude spin recovery requirements.

My only consideration was elimination of the "tail wag" in turbulent air.

Tom Parkes

Tom,

Thanks for sharing that.  I knew there was a reason why I waited to paint my
ES.

Mark S.