Steen Aero Lab

New millennium technology meets the biplane

(From Sport Aviation, 08/2002, Page 56)

By Budd Davisson
Photography by Phil High and Jim Koepnick

Picture this: you’re standing in the middle of a small factory where the product being built is obviously a biplane. It’s a typical biplane with built-up truss ribs and a steel tube fuselage. It’s traditional through and through. Nothing exotic.

Now you’re watching parts of the wing ribs being built. But what’s that machine cutting the plywood rib gussets from a large sheet of stock? Instead of a little old lady at a band saw, a computer-driven spindle turning 110,000 rpm is carving expensive aircraft plywood into nested geometric shapes with virtually no waste. As the individual gussets fly from the sheet, they are drawn into a vacuum dust separator where they come to rest in a basket, ready to be included in a new wing kit.

Nearby, another automated system consumes endless lengths of rib material, cutting it to length and putting the appropriate intersection angle on both ends. The next machine is spinning away on its own, leaving nothing but fine sawdust and the finished contours of plywood nose ribs and compression plates in its wake.

In the metalworking area a large gantry moves an abrasive 65,000-psi water beam that rapidly cuts aluminum and steel flatwork profiles like a cookie cutter.

Are these some space-age biplanes being put together by NASA? No, they’re the ever-popular Steen Skybolt and Pitts Special, just two of the biplanes that have been pulled into the 21st century as part of the new incarnation of Steen Aero Lab.

The name Steen Aero Lab has been around for a long time. It was in the early 1970s that Lamar Steen decided he wanted a biplane built to man-sized proportions, so he designed and built the Steen Skybolt. He began shipping plans out of his Colorado home base, and it wasn’t long before the two-place airplane had carved out a solid following in sport aviation.

The Hale Wallace Legacy

One of the Skybolt builders was Hale Wallace. He was well known for the attention to detail and craftsmanship he brought from his world-class model airplane career and applied to his aircraft. He and Steen struck up a friendship, and when Wallace retired from IBM in the early ’90s, he bought the rights to the Skybolt and set up a component manufacturing business on the beautiful grass airport at Marion, North Carolina.

Besides being a craftsman, Hale loved aerobatic biplanes, and as he looked around, he decided the world needed a company that specialized in these biplanes, which meant he needed to expand past the Skybolt into other aircraft. he sat down with Curtis Pitts and struck an agreement that gave Steen Aero the rights to the S-1C series of flat wing, single-place Pitts Specials. Then Curtis designed a new wing for the airplanes, which incorporated the aileron technology he had introduced on the Model 11 Super Stinker. With those wings the S-1C became the S-1SS (for Super Stinker). It was, in effect, a four-cylinder Super Stinker with symmetrical wings and a much higher roll rate than even the S-1S round wing Pitts.

Then, the rights and plans for Vernon Payne’s legendary Knight Twister designs became available, and it only seemed natural that Hale add them to his growing stable. To round out his biplane efforts he built a Knight Twister Acro, and it won Reserve Grand Champion Plans-Built at EAA AirVenture 1999.

All the Wallace airplanes had two wings and needed flying wires. At that time there was only one manufacturer of flying wires in the country. Hale didn’t like the idea of having to deal with what he saw as an unreliable and difficult source for his wires, so he searched for an alternative supplier and, in so doing, became the only distributor for Brunton’s flying wires in this country. Brunton’s, a Scottish manufacturer, is the world’s oldest supplier of streamlined tie rods, having developed them in 1909, just six years after the Wright brothers’ first powered flight.

Another unifying characteristic of the biplanes in the Wallace stable was that they all required high-performance lightweight propellers, so he became the distributor for Hoffmann composite propellers in the United States. It would be an understatement to say Hale was something of an entrepreneur. He saw the business side of sport aviation, but he was also an old-fashioned kind of craftsman, and everything that came out of his shop was done the old-fashioned way: by hand and eyeball. Walking into his shop was no different than walking into any aircraft manufacturing facility circa 1935. The airplanes were traditional. The materials were traditional. The methods were traditional.

Unfortunately, aviation lost Hale to cancer a short time ago, but he saw the end coming and planned accordingly. He didn’t want Steen Aero Lab to die with him. He found a buyer for the company, but at the same time he also unwittingly set in motion a process whereby Steen Aero Lab designs and materials would remain traditional but the methods that turn them into flying biplanes were about to enter into the new millennium.

The New Steen Aero Lab

Two longtime aviation friends and business partners, Paul Goetsch and Jere Larson, of Melbourne, Florida, had been working with a small team on a business plan to use CAD/CAM and CNC automation, particularly waterjet, laser, and ultra-high-speed CNC router technology to build components for kit- and plans- built airplanes. It seemed that construction times could be dramatically reduced by having all the components pre-cut and the difficult fabrication manufactured in advance. With the right automation, costs could be controlled by reduced labor and better material utilization.

Paul and Jere were also shopping for a Skybolt, and in this pursuit, they got to know Hale. Jere shared with him the vision for the automated CAM and CNC manufacturing enterprise that would become known as Aircraft Shapes. Everyone saw the potential synergy of applying these processes to the production of the Skybolt, Pitts, and other aircraft. These discussions led to the acquisition of Steen Aero Lab as a sister enterprise to Aircraft Shapes.

Hale was to be actively involved in the transition of Steen and its relocation to central Florida. Unfortunately, the fates had something else in mind. Hale abruptly passed away, leaving Paul and Jere to scramble to run the business from Marion while moving the entire business to a new 17,000-square-foot facility in Palm Bay. Mark Eckenrod had been Hale’s fabrication technician for five years, and he joined the new team, which helped maintain continuity during the transition. Still, it was a tough period for them.

Besides having to sort through the tons of plans and tooling pertaining to three different biplanes, they had to negotiate with both Bruntons and Hoffmann to solidify new business relationships. It took a while, but everything fell into place, and Paul and Jere began to do what they do best — bring new technology to existing processes and production.

Both Jere and Paul trace their aviation roots back to their high school years. Jere grew up in Anchorage, so airplanes were a natural part of his environment. His dad and uncles used floatplanes as their family’s second car. Paul started flying in high school, while living in southern New Jersey, and was renting airplanes before he had a driver’s license.

The duo met at Florida Tech, where Jere majored in electrical engineering and Paul in mechanical engineering, and both became commercial pilots. Paul went to work with LTA developing tethered aerodynamic balloons, called Aerostats. They were designed to be stationary radar border surveillance vehicles for the U.S. Customs Service and research platforms for Naval Research Lab. At the same time, Jere was working in the telemetry group of Lockheed’s Fleet Ballistic Missile at the Cape.

Although they had met in college, they became good friends when Jere was brought in to work on an airborne electronics package for the LTA Aerostats. They began to collaborate on various technical projects. At the time, the personal computer was a new phenomenon, and most companies were still trying to get a grasp on what this new gadget could do for them. Paul and Jere were of the age that they intuitively knew what the computer could do, and they began to apply it to automated material processing. Flash ahead to today. The cooperation between the two eventually resulted in an information services and automation enterprise with 125 employees specializing in high-tech, computer-based processes.

When the partners first traveled to North Carolina to meet with Hale about the possible acquisition of Steen Aero Lab, they received an immersion course in Skybolt and Pitts lore. Hale was so open, almost joking, about his medical condition it was amazing. He passionately wanted the company to continue in good hands, and the more we looked at it, the more symbiotic the idea became, remembers Paul.

So, two high-tech manufacturing computer types instantly became biplane manufacturers. At the time they had already launched what would become Aircraft Shapes, and they were setting up a waterjet cutting operation to profile parts in aluminum, 4130 steel, and various gasket materials.

In setting up their businesses Paul and Jere used their machine design and integration experience to create procedures and processes that allowed them to build manufacturing systems in-house, rather than having to buy expensive machines that might only do one job for them. This approach gave them a huge amount of flexibility, and because everything they use is CNC, it is a relatively simple matter (for them, anyway) of marrying computers, software, and controls with the servo systems and mechanics needed to carry out the required operation.

When we looked at the biplanes, especially the Skybolt and Pitts, we saw dozens of tedious processes where we could employ automation to eliminate the labor the airplane usually requires, Paul says. Because of our other businesses, we were already in the habit of attending major machinery auctions around the country, and we started keeping an eye open for gantries and actuators that could be utilized in building parts for these biplanes and other aircraft.

One of the first tasks was to put the Skybolt and Pitts drawings into CAD/CAM forms from which the computers could produce shape and profile information. This information was then fed into software, which now turns the geometry of the part into three-dimensional tool path coordinates for the CNC machines to follow.

Steen Aero Lab and Aircraft Shapes are evolving as separate, distinct enterprises, although they will always remain kissin’ cousins. Paul is taking the helm at Steen, and Jeff Lammers, who has an impressive background in aerospace manufacturing, is heading up Aircraft Shapes.

The recent growth of Steen Aero Lab has been brisk, says Jere. Hale ran it as a retirement business, and he was determined to keep it to three people, which meant he couldn’t begin to service everyone who contacted him. The unsatisfied demand for Skybolt and Pitts components and materials has really kept us scrambling.

What’s Next?

There is a wave of new developments at Steen these days. Curtis has been doing a lot of design work on both the Skybolt and Pitts designs, including aerodynamically balanced Super Stinker aluminum ailerons for each. Jere arid Paul struck a deal with him to produce and market the original Pitts inverted oil system, which was copied almost verbatim by others and became the industry standard. This system will be available for both four- and six-cylinder Lycomings, and it will carry the Pitts name in honor of the original innovator. Curtis has been a great friend to us, says Jere.

The vision of the new Steen Aero Lab is to provide highly prefabricated kits for the Skybolt and Pitts, which will dramatically reduce build time. Hale referred to these designs as big model airplanes, arid he had a good point, says Paul. We are reducing the build time by pre-cutting the majority of parts and providing pragmatic assembly jigs and fixtures for the builder. The design for the new rib jigs is really clever, and allows an entire rib to be assembled and epoxied in one operation. A Skybolt or Pitts project now becomes more assembly than anything and is much less intimidating for the first-time builder. Using automation to eliminate most of the difficult and tedious building tasks, we enable a much broader builder community.

All of the flatwork for the aluminum and steel fittings are cut by waterjet, which eliminates the problems of edge hardening in steel caused by lasers and produces a very smooth and accurate edge. A builder can order all of the flat parts and bend them himself, or we’ll bend, weld, and finish them. We’re working on a precision CNC tubing cutter to produce fuselage kits for the Skybolt and Pitts fuselages in a wide variation of component package options. A builder will be able to order a fuselage kit completely precut, so all of the tubing fits together perfectly, or he can order a tacked fuse ready for finish welding. Completely welded fuselages with various options are currently available.

The wing packages are very complete, with all the flatwork pre-cut. However, ribs or any part of the wing can he bought in any stage of completion up to and including complete wings ready for covering. As always, the company will tailor components and materials to the requirements of the individual, from the scratch-builder to the 51-percent guy.

One of the things we’re really trying to do, as a company, is be builder-friendly, Paul says. For one thing, if a builder wants to use our jigs or come work with our people while we’re assembling their subsystems, we have a ‘builder’s suite’ that includes a kitchen and a shower, right there in the plant. If they want to put in 16-hour days, they can have at it! We really like to have people come visit us and see what we’re up to.

In late 2001, Steen Aero Lab added two more biplanes to their stable. They acquired all the rights to the Firebolt (a Skybolt derivative) as well as the rights for the plans for the 1929 Great Lakes trainer (acquired from friend and Great Lakes guru Harvey Swack). In case you’ve last track, that is a total of five biplane designs under one roof.

Right now most of the builder interest is on the Skybolt and the Pitts, Paul says. We do, however, regularly sell plans for Vernon Payne’s various Knight Twister designs. We are selling plans for the Great Lakes, and if there is enough interest, we’ll produce the difficult components and maybe a kit.

It’s an interesting dichotomy; computerized automation and biplanes would seem to be at opposite ends of the spectrum. However, when the homebuilding virus infects an automation guy’s brain, there’s bound to be a cross breeding of interests and experience. Steen Aero Lab for the new millennium is the product of such a process.

Gee, I wonder if Paul and Jere have thought about acquiring the rights to the Antonov AN-2 and offering kits?

NOTE: You can view more articles by Budd Davisson on his website: Airbum.com