Dave you are creeping me out here. Bella Abzug?
Justin -
Well, beauty is in the eye of the beholder..
And there's an age at which it's like an old dog chasing a car - what
the heck do you do with it if you ever catch it?
But more to the point - Joe and Don had (have?) an excellent discussion
on V-tail design on the DJ website. Having flown quite a few of both
types, the differences are ones of aestehtics but with the caveats:
- For the same tail moment, the volume coefficients (horizontal and
vertical) really need to be about the same to make a fair comparison. As
Mark noted in a recent post, the euro V-designs tend to be low in the
vertical component of these design values. I've noticed this is in
several 2M euro designs that I've tried and the problem (for me) is too
little vertical volume coefficent (often half of what we'd use in a
normal X-tail) and low dihedral angle. These complement each other to
make the rudder yaw response rather weak as compared to many US designs.
Consequently, my impression is that the 2M ships that are sold as TD in
the US are really converted slopers for which a low rudder volume
coefficient and EDA isn't all that critical. Since the yaw response to
rudder is weak, and the dihedral angle is low, it can be tricky setting
up aileron differential and rudder compensation for coordinated turns
with these ships for TD purposes (again - for me).
- For a V-tail, you don't need much elevator travel but you need a lot
of rudder travel. This seems to be compounded by a weird pitch-yaw
coupling on large 'rudder' type movements in a V. That can require
differential for the V surfaces as well. My impression is this gets more
pronounced if the hinge line is angled significantly.
If you look at the Super-V designs of Mark LeVoe, you'll note that the
horizontal and vertical volume coefficient is about in the mid-range for
conservative X-tail designs. I think for US TD work, most folks have
found the handling of a Super-V to be very good.
Different strokes for different folks. A V is a little more challenging
to set up properly but works fine once you get there.
No offense intended to any euro designers with these comments. Just
personal observations from a limited number of well-crafted ships.
- Dave R
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