The Classy Cabin Ace SJ

When this small aircraft flies overhead, the questions start flying as well.

What kind of airplane is that? Is it an antique?

Well, it does resemble one, with its angular windshield, outrigger gear, large spoked wheels, and square-shaped rudder — but it isn’t.

This classy Cabin Ace SJ (N486N) is a special blend, concocted by a couple of retired chemists who are avid homebuilders and pilots.

Steve McGuire and Jim Yates, both of Ponca City, Oklahoma, joined forces to create this little jewel. They’ve been friends for 45 years, have flown together for 20 of those years, and have restored several 1940s airplanes. Now, they’ve built their first experimental airplane together, and it’s a keeper.

“This airplane is a replica of a 1929 Corben Cabin Junior Ace,” shares Steve. “We built it from partial plans, which I got from Robert Taylor at the Antique Aircraft Association, and we went by historical photographs as well. So it’s largely designed by us, and based on the aerodynamics of a Baby Ace Model D, which I built back in 2005.”

As a brief bit of history, O. G. “Ace” Corben started designing and building light sport planes in the 1920s, and founded Ace Aircraft Manufacturing Corp. in Wichita, Kansas, in 1929, to market his designs. Though that company was ephemeral, Corben continued with his sport plane endeavors, and became a lasting source of inspiration to aspiring homebuilders. Paul Poberezny revived interest in the Corben designs in the 1950s and ’60s.

Steve and Jim took a few liberties with the original design, chiefly to enhance comfort and performance.

“We increased the size of the two-place cabin cockpit – people are bigger now than they used to be,” smiles Steve, “and instead of using the little radial engine that was on the original Cabin Junior Ace, we installed a modified Continental A-65-8 that has C-85 cylinders – that makes a really nice engine!”

Steve encountered a bit of a challenge when he flew the Cabin Ace the first time.

“We built the tail section to the plans, but when I test flew after we finished it in November 2013, I was concerned about the size of the tail. So we rebuilt the tail that winter,” recalls Steve, explaining, “we increased the height of the vertical stabilizer and rudder by 8 inches, and we increased the span of the elevator and horizontal stabilizer by 20 inches. That made a huge improvement in the way this airplane flies.”

N486N has a wingspan of 30 feet, and a length of 19 feet 6 inches. It weighs about 825 pounds (with a gross weight of 1,320 pounds), and easily carries two adults and 23 gallons of fuel (two 11 gallon wing tanks and a one-gallon header tank).

It cruises at 95 mph and stalls about 40 mph. Steve climbs out at 75 mph, and flies about 70-75 mph on final.

“That’s faster than you need to be, but it’s very light, with quite a bit of drag when you pull the power back,” explains Steve, “so basically I carry power most of the way down final. It has a trim tab below the horizontal stabilizer, which is cockpit-controlled and works very well. I’ve always three-pointed it; it has plenty of rudder authority. I have about 90 hours in it now, and the only serious cross-country flight was up to Blakesburg, Iowa, this year.”

The outrigger gear, which is perhaps the Cabin Ace’s most notable feature, was specially engineered by Steve and Jim.

“It has an 8-inch die spring for shock absorption, which works great, and you can buy those around $20 each. I built the wheels,” he shares. “I used an aftermarket ‘Harley’ rim and spokes. The hub is something I designed and had the local machine shop make, and a friend of mine did the welding. It’s a custom-designed hub and brake assembly, using a go-cart brake, which is dirt cheap – about $50 a pair. All you need brakes for anyway is tight taxiing and a run up, and these easily hold a 1600 rpm run up!”

Speaking of rpms, one notable instrument in the panel is the large vintage tachometer. It was originally in an Aeronca, and when it was given to Steve, he had it overhauled in Wichita and re-silkscreened.  Then he applied a small vinyl graphic of the Corben logo to its face.

Steve and Jim thoroughly enjoyed building their Cabin Ace SJ (“S” is for Steve and “J” is for Jim), and flying it is a pleasure as well.

“One of the things Jim and I especially enjoy is having the only one of its kind,” Steve says with a smile. “It draws attention anywhere it goes. I’m not a Corben historian, but I believe there were only two Cabin Junior Aces ever built by Corben. There have been replicas of the single-seat cabin airplane, but not the Cabin Junior Ace.”

These two homebuilders haven’t allowed their tools to sit idle on the shelf; they’re already well underway on their next project.

“We’re building another homebuilt now, and it will look like a single-seat Monocoupe 113, but it’ll have the aerodynamics of a Baby Ace, with a Continental A-65. We’ve named it the ‘Baby Coupe.’”

We’ll be looking forward to seeing it flying overhead, Steve and Jim!