Bob,

I have similar interests in aerobatic airplanes and economy and have
researched what options there are rather extensively. I'll share some of my
findings and thoughts.

I have decided that a two seat aircraft is needed for cross-country utility
primarily and passenger carrying secondarily. Most single seat aerobatic
planes have only enough baggage space for a toothbrush and maybe a towel.
The safety aspect of being able to have an experienced pilot along when
trying out maneuvers for the first time is also a major consideration. That
being said, there's no question that a single seat design will almost always
outperform a two seat due to lighter wing and power loading.

Looking at the expense of building various designs it has become evident
that there is very little difference in the cost of the airframes even when
comparing single and two seat designs. The use of composites does make some
difference, but unless you're buying the parts, you have to make the tooling
to produce the parts, which becomes quite expensive. To my knowledge there
are no composite aircraft that would be competitive at the advanced level
that are made using moldless composite construction. The cost of materials
is a relatively small part of the cost of the completed airplane. The cost
of manufactured parts such as wheels, brakes, instruments, fittings, etc. is
pretty much the same no matter what design you choose. The greatest
difference is in the cost of the powerplant and propeller.

The Lycoming -360's are in such high demand that the prices are quite high.
For about the same amount of money there are Lycoming -540's. They will
cost more to overhaul due to having 2 more cylinders and will burn more
fuel, but they also make more power, a really good thing for a two seat
design. There are Franklins, Continentals, and others that aren't seen on
aircraft competing in advanced aerobatics, and unless you want to discover
for yourself the reasons they aren't used, probably should be avoided. The
M-14P, a Russian ("new" old stock) or Romanian (new) 9-cylinder radial, is
the most bang for the buck. About half the money of a Lycoming, 350 HP,
about the same fuel burn as a Lycoming -540, enough support in the US for
there not to be parts problems. These engines are used on Sukhoi's and
Yak's built for aerobatics, also the Pitts Model 12.

As for propellers, there are many fixed pitch props that are suitable for
aerobatics, but for the advanced level, almost all of the planes you would
be competing against will be equipped with constant speed props. The single
seat Pitts would be almost the only exception. Constant speed props that
are suitable for aerobatics are not the same as what may be found at a
salvage yard off a light twin. Most are not made to deal with the
gyroscopic forces that aerobatics create and will not last long before
failing, most likely at the hub and most likely by shedding a blade. MT
makes aerobatic props that are suitable for 6 cylinder Lycomings and the M14
that cost about $10K. Whirlwind and Hartzell make ones that run about $40K.
I'm sure they're better, but I'm also sure I'd buy the MT. There is a
2-bladed constant speed prop that is available with the M14 that is OK for
aerobatics, but doesn't develop as much thrust as the MT, Whirlwind, or
Hartzell. It has wood blades which is good because they are light, but my
experience has been that wood props change balance and shape with the
weather as the moisture content changes. But it is very inexpensive.

If your objective is mainly to compete, probably the best option is to
finance a Pitts S2. The -C would be the best and most expensive, however
a -A will be enough to be competitive in advanced, with more finesse
required from the pilot. The payments won't be real small, especially with
insurance added in, but it will get you to the flying part without years of
construction. It is a REALLY BIG project to build an airplane, with lots of
skills that not only need to be learned, but mastered, before using them on
a part that you are going to trust to keep you from making unplanned
landings. When you look at the big picture it is much more efficient to do
the things that you have already become good at to earn money, and then
spend that money to hire people that already have the skills and experience
to build reliable airplanes. However.....

If your objective is to build an airplane, and then compete in it, that's
another matter entirely. Building your own airplane being the first, and
main, objective changes the priorities completely. What you want to create
is the driving force in the decision. From your message I gather you have a
preference for biplanes, and that really limits the choices for the level of
performance you want. There is only one that meets all your criteria, the
Pitts Model 12. While the plans version and the kit version differ, the
changes are not secret and can be made by anyone building from plans. The
change that has the greatest impact on performance is shortening the wing,
increasing the roll rate. While the Kimball's won't provide plans for the
modifications they developed, they are incredibly helpful to anyone wanting
to modify the design.

You can find an incredible amount of support information in The Biplane
Hanger, a website and listserver that supports anyone building a plane with
2 wings. It's the best collection of technical information for someone
building an airplane from steel tube, wood, and fabric that I have found.
http://gf.de/biplane/ The archives are a great resource, and any question
posted to the list is quickly answered by at least one person with actual,
credible knowledge. The behavior of the participants on this list speaks
very highly of people that build airplanes. There is an associated list
that is only concerned with the Pitts Model 12: http://gf.de/Pitts12/ Both
are worthy of checking out.

I guess it's pretty obvious what my choice is.

Clayton Smith
PP SEL, A&P
1946 Cessna 140
Sammamish,WA

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