The Brilliant Bentzen Sport

“We’re all astounded at what this Bentzen Sport can do,” says Rob Bach of Pell Lake, Wisconsin, adding, “Bill and Ken Bentzen were engineers and brothers; they only built one plane — and they built it perfectly.”

Though the airplane is 54 years old, it’s a fresh face on the flight line today, with an intriguing history.

The Bentzen brothers flew their airplane to Rockford in the early 1960s, and continued flying it locally in Illinois and Wisconsin for years. It was restored in 1986 and remained hangared until it was flown once in 1993. The brothers preserved it well, never knowing that its next flight would be in April 2015, with Rob Bach at the controls.

Rob and his wife, Laura, recently welcomed this singular 1961 Bentzen Sport (N4964E) into their hangar. They came across the airplane in a rather roundabout fashion.

In 2014, Rob learned of Bill Bentzen’s estate sale in Kenosha, Wisconsin, and asked for a picture of the only airplane listed for sale. He soon realized it wasn’t a Rose Parrakeet, as he had hoped, so he didn’t pursue it any further.

Then a friend of Rob’s bought the airplane, but quickly realized he couldn’t fit inside the 19-inch-wide cockpit. So he encouraged the Bachs to take a look at it.

Rob recalls with a laugh, “Laura hopped inside and discovered that she fit right in it, and said, ‘oh, we’ve got to have this!’”

So they bought it, and started learning more about it.

“The Bentzen brothers made an affordable little airplane that was easy to build and fly, but could still roll upside down once in a while,” he relates. “They were about 35 and 40 years old; one brother hadn’t even started learning to fly yet, and the other one wanted to have something kind of sporty. A friend of theirs crop dusted in Cubs, and when his 1947 Cub got bent up, he just gave it to the brothers.”

The brothers modified the Cub tail section, shortened the wings and struts, and retained the Cub’s firewall-forward configuration.

While the aft section of the fuselage appears to be Cub, the portion from the cockpit to the firewall was welded from scratch, according to Rob.

“The gear legs are spring steel and it has expander-tube Hayes brakes, but they cut the wheel halves down the middle to make them narrow enough to use Ercoupe nose wheels for the main landing gear,” he explains.

After re-installing the wings, Rob replaced the fuel lines, fuel valve, and the pitot static system lines and instruments. The engine had been pickled and was in good condition, including its simple inverted oil system and fuel recovery system.

Then it was time to address that looming question: How do you learn to fly a single-place airplane?

Old time, well-known homebuilder Ken Flaglor was the only pilot besides the brothers who had ever flown the Bentzen Sport, and he kindly supplied the answers to that question.

“Ken said it was very docile, straightforward, and had a good roll rate. So I took it up and flew it around most of the flight envelope,” shares Rob, “and my aerobatic friend did a full routine with it, and was very impressed with what a 65-hp engine can do on the right airplane.”

The airplane has a 12-gallon fuel tank, and its Continental A-65-8 burns 4 gph at a cruising speed of 80 to 90 mph. It takes off at 60 mph in about 300 feet, and lands in 400 feet. Its wingspan is 18 feet, 4 inches, and its fuselage measures 17 feet, 10 inches from prop to tail. With an empty weight of 550 pounds, it can accommodate up to a 185-pound pilot and full fuel.

“It stalls at 52 mph,” says Rob, adding, “it has a tiny little wing, and it comes down like an absolute rock when you pull the throttle. The wing has almost no washout, so it stalls crisply with hardly any warning. The control harmony is excellent; all the controls are very light, but it’s not a squirrely airplane. It’s fun seeing Laura, a student pilot, jumping into a little mid-wing and flying it so well. She flies it better than I do!”

Rob decided to answer everyone’s “What is it?” question by creating a 1960s stylized logo on the fuselage.

“When I was a kid, Bob Taylor (founder of the Antique Airplane Association) used to call me ‘Sport,’ and since the Bentzen is a ‘Sport,’ I found a 1960s graphic of a kid’s face and I designed all the lettering as well. Laura thought the kid looked like Elroy Jetson, and the airplane kind of looks like a little Jetson-mobile, so she got a tiny Elroy Jetson figurine and he’s sitting on the glare shield!”

Rob admits he was surprised by the Bentzen Sport’s flying capabilities.

“I’m glad my pre-conceptions were shattered,” he shares. “It’s a good life lesson to stay open, to stay happy, and allow yourself to be surprised. It’s added to the whole experience when we open the hangar and see that little guy smiling and ready to go flying, we feel like, ‘yeah, we’re having a great day!”