Hi Duane,

I just came back in town from a trip. In general everything that you wrote fits. The Taurus was good for it's time to do the required pattern of that time and using the radios of that time which were terrible! I hated the old reed sets - you had to tune and tune and fiddle and tune - I am totally impressed that Ed could keep his Taurus in one piece for as long as he did.

It seems that Ed wanted an airplane that required an airplane that needed a minimal amount of control inputs. Line up the level approach for the maneuver and push one lever until the maneuver was done and watch it fly out level. With the pattern requirements of that time it resulted in a semi-symmetrical airfoil and relatively high dihedral wing for mostly upright flight. Then add a swept tail to hopefully get a bit of up elevator effect. But whether or not the Taurus was the best at that time is so totally influenced by the pilot flying it that it is a real problem to be sure. I remember seeing models at the time that I believed had better aerodynamics for that pattern. However Ed's flying ability (resulting from a lot of practice in the previous years) was good enough to beat the pilots flying the other airplanes. Remember that the winners and runner-up scores are not that much different in the contests.

You can make the Taurus do some of the popular maneuvers of today but that doesn't mean that it is "comfortable" doing them. A much better airplane, even for the old patterns, is one that can be seen at any modern FAI or AMA contests. These look like flying fish and are totally symmetrical. You can command any control deflection and get a result that is just what that control should give. With motor control available (especially with electrics) the speeds are nicely slow and totally constant in all attitudes and maneuvers. The airplanes would probably fly just as will with reeds - you would have to do a little more beeping on the reed levers since there is no attitude stability built in.

With this as a measuring stick the Taurus falls into the aileron trainer class. I am in the process of gluing sticks together to build an Astro Hog but only because I wanted one so badly when I was a kid that my teeth hurt!! The Taurus would fit in the same category. I would love to have one but I certainly wouldn't expect it to be capable of doing everything that I have in my mind with respect to maneuvers.

Oh yes, back to the vertical tail - it is a wild guess as to how much effect a swept vertical/elevator would have. You would have to build an airplane that has easily interchangeable vertical tails (bolded on) and fly the airplane with each tail. Even better would be the ability to stick it in a low speed wind tunnel.

People typically don't do that. They change the vertical tail and then think, hummm, let's change the xxxxx a bit and maybe the yyyyyy a bit and soon it is a different airplane and they have no idea if the original change made any effect at all. Then if someone asks about it the original reason is stated with no proof.

In full scale airplanes the vertical tails are sized to give a certain dampening rate after a displacement in yaw angle and the rudder sized to give a yaw rate after control input. We don't do that. As Cees noted we look for the results on maneuvers such as snap rolls, spins, stall turns, 4 point rolls, etc. There can be a lot of variation in vertical tail sizing that work when we are using observation for our analysis.

It is interesting stuff...

Ben