One-of-a-kind Stinson

If you want to draw a big crowd at an aviation event, you need to have a vintage design, a red airplane, or a one-of-a-kind airframe. If you happen to own a Stinson Model “O”, also known as a Senior Trainer, you have all three.

The Stinson, a replica of the 1930s-era design, made its debut on the air show scene in July at the Arlington Fly-In in Washington.

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“It is one of a kind,” said Lynda Elaine, of Evergreen Aviation Services at Scappoose, Ore., who was on hand to answer questions about the airplane, of which there were plenty. “When people get up close to it they do a double take. They expect it to be a biplane, but it isn’t. They’re also surprised that it is an open cockpit design. It was the only open cockpit design that Stinson produced.”

The O model, which rolled off the assembly line in 1933, has a parasol wing and teardrop wheel pants. It can be soloed from the front seat, unlike many other planes of the era.

If you have never seen a Stinson Model “O” — or even heard of it before — you’re not alone, said Elaine, noting, “Only 10 of them were built. They were sent out of the country, to Brazil, Peru and China. One stayed in California and was an instrument trainer, but no one knows where it is today. There is no record of them anywhere.”

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The airplane is owned by Brad Poling and Jeff Teel from Sacramento, but was built by Evergreen Aviation Services under the guidance of Jeff Paulson.

The first challenge, said Paulson, was creating plans to work from. There were no full-sized plans to be found, because so few of the planes were built and they were sent overseas.

“Only one of the Stinson O models stayed in the U.S. after it was manufactured,” he said. “It went to Prosser Flight School in Long Beach, Calif., then it was sent to Love Field in Texas. It was there during World War II. It went off the Civil Aviation Administration (precursor to the FAA) registry in 1944.”

What happened after that is anyone’s guess.

“Brad called a lot of different people looking for plans, looking for wreckage, but there was none to be found,” said Paulson. “Finally he found a Stinson SR5A in Hastings, Neb. It was a good donor project and I drove out to Nebraska, picked it up, and drove it back to Oregon.”

According to Paulson, there were enough similarities between the O model and the SR Reliant that they were able to make it work.

“Stinson used the Reliant wings, tail and landing gear and modified them for the Model O,” he said. “Robert Hall (designer of the Gee Bee) was at Stinson at the time. He built the center section and landing gear. They took the parts of the four-place cabin airplane and made it a two-place open cockpit parasol wing design.”

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Poling also found plans for a quarter scale radio controlled model of the Stinson O. The dimensions were expanded and the project began.

The team at Evergreen Aviation Services, which has several award-winning aircraft to its credit, was up to the task, according to Paulson. “We have done Wacos, a Fairchild 24, a Howard, a Travel Air 4000, and a Stearman,” he said. “We pay attention to detail. It is not skin-deep beauty — it is all the way through the airplane.”

Paulson, who said he is “the chief cat herder with a group of extraordinarily talented people,” added that for 28 months there were one to five people working on the airplane at any given time.

“This was a big challenge because we didn’t have a whole lot to go on,” he continued. “There was a lot pressure put on me just from the design aspect. Normally we have a little more to start with. With this, we had Reliant parts and 20 photographs of the Stinson O when it was under construction in the factory. There was a lot of head scratching on our part.”

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Because there were no plans, the replicators had to reverse engineer the design of systems. “Everyone in the shop had a hand in it, from how to run the trim cables to how to rig them,” Paulson said. “We had pictures of them in the cockpit, but no pictures to show how they got back to the actuator. The oil cooler presented another challenge. It could be extended in flight then pulled back in and we had no idea how they did it. Eventually, the team figured it out.”

The team had the Type Certificate for the Model O, which indicated how big the wings and fuselage were, and that told them how big the wing panels had to be.

“We took the parts from the SR5 and cut 2 feet off the wing panel, moved the struts in by 9 inches, added five new root ribs, slightly modified the fuel tanks, took off the flaps and hardware and made a new aileron bay,” said Paulson.

Using photographs, they crafted the center section, which has a very unusual hour-glass shape, according to Paulson, and the landing gear.

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The covering is Seconite with an Air-Tech coating. There are no Phillips head screws anywhere on airplane. The fasteners are lock-washers or castle-nuts with cotter pins. Copper line was used for the airplane’s fuel, oil and manifold pressure lines. The throttle quadrant was designed by the team and made from spruce laminate with a mahogany control stick.

“Through the middle of the stick there are aluminum conduits for running push-to-talk switch wires through,” he said, noting the modern avionics, including radio and transponder, are hidden in the map case in the front cockpit to protect the integrity of the design. “The antennas are hidden as well,” he said, adding, “so are the ELT faceplate, intercom and circuit breakers.”

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The replica sports a Lycoming 680-13 engine. “It came with the Reliant project,” said Paulson. “The original had a 680 series engine in it. Radial Engines Inc. in Tulsa, Okla., overhauled it for us and the Hamilton Standard prop was overhauled by Western Propeller in Hood River, Ore.”

According to Paulson, the Stinson cruises at 130 mph and lands at 70 mph.

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Evergreen Aviation Services always places step stools around their aircraft at air shows and fly-ins so people can get a better look.

The sheet metal cowling was fabricated from the cowling of a Cessna UC 78, also known as the Bamboo Bomber.

The interior was done by Oregon Aero, which is also located at the Scappoose Airport.

“We had laminated the plywood seat backs and they did upholstery and lumber supports. It looks authentic. The instruments were sent out to be refurbished with the instruction that they should ‘look vintage’ but not have the radium on the dials.”

The attention to detail has not gone unnoticed by visitors or judges at air shows and fly-ins. “We won the Bronze Lindy at Oshkosh,” said Paulson.

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The awards are nice, but the best reward is seeing the reaction of people who see the airplane.

“On the first day of the show a man came up and said that he flew the Stinson Model O when he was in Texas,” said Paulson at AirVenture. “A few days later a 95-year-old man came up in a cart and said that he flew the airplane when it was in Long Beach. He said he was working for Howard Hughes at the time and learned to fly instruments in it. The way they did it was the pilot getting instruction was in the back cockpit with a cover zipped over him and the one in the front was the safety pilot.”

To help people get a better look, Paulson’s team placed wooden step-stools around the plane.

“We do that with all our airplanes,” he said. “One year when we had the Travel Air at a show, over 650 people, from the ages of 3 to 93, sat in that airplane in five days!”

For more information: EvergreenAviationServices.com

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