Tail Configurations?

[Gyro28866]

Minnesota Mike
An HS IS important for dynamic stability (compared to an old Bensen HTL design without a true functional HS)...larger is better, in the prop wash allows for a smaller surface area, but keel mounted allows for a truely functional flight surface (since it's NOT in the prop wash).

Mike are you stating that the Bensons are HTL,
I think at Benson days (possablly last year) that a double hang test was done and it was found on an original Benson that it was actually CTL.
From what I have read and heard, when you modify a benson and install a larger, higher hp engine for more thrust, and raise it relation to the mast. you create a HTL monster.
I fly a MAC powered Benson B7m, and she flies very stable. It does have a flat plate HS mounted at the most aft section on the keel.
You might still be able to see pictures of this gyro on the Shelbyville 09 flyin. (Orange tail surface)

[REDHORSE556CES]

I've seen the classic example of that in Southeast Asia. During days of high humidity the vapor trails off the prop tips of the C-130s on take off created a spiral that would shrink down the further it was from the props. I found it fascinating; to the point that I would stop working long enough to watch it until the Herk lifted off.

[Jazzenjohn]

I believe origional Bensens were slightly HTL. They used to have fairly heavy steel gas tanks mounted low on the axle. The Bensen that was hang tested had a seat tank which moved about 45 pounds of gas and fuel tanks and heavy wheels up 12" or so. The seat may have been a few inches higher than stock as well. The seat tank, even if it was at plans height raised the pilot a few inches too. I would estimate all that would raise the cg about 1-3 inches. The big effect of a stab on a Bensen is to make it more pitch stable, as opposed to simply overcoming the HTL. You can put one or several H Stabs on the gyro but, in my opinion, it is more a matter of enough stab area x moment arm vs not enough stab area x moment arm, rather than where it is placed.

[Tinman]

Here is a picture of the T Tail from starbeegyros.com...

[napsover]

Originally Posted by mabik

Just out of curiosity, has a canard ever been employed on a gyro? If not, what are the theoretical advantages or disadvantages? One disadvantage I see on a pusher, is that it would be out of the prop wash. I can also imagine some adverse reactions to up and down drafts. What do the experts say?
doc matt

like this?

[Jazzenjohn]

I can't think of very many situations where you would want an aerodynamic device that tended to produce instability. You want the airframe to point toward the relative wind. The large canard on that gyro would tend to point the airframe away from an updraft or downdraft, exactly the opposite reaction desired. It is also pretty large so it would have a strong effect. Not good.

Commander Wallis had at least one gyro with a very very small canard. I believe it's purpose was to finely trim the airframe to the relative wind to minimize drag during a world record speed attempt. It was a tiny fraction of the size of the canard in the picture, and isn't on any of his "normal" gyros. I would be pretty skeptacle of any canard on a gyro.