For almost three years, a resident in the coastal town of Penobscot has been quietly toiling away in his garage, poring over design plans, bending metal and fastening rivets.
Now the fruits of his labor are almost finished: a gleaming, silver-skinned experimental aircraft expected to take flight in the spring.
John Marples, 79, is no stranger to airplanes. A private pilot for decades, this is his fourth home-built plane, although it’s his first since moving to Maine a decade ago.
His soon-to-be-finished Thatcher CX4 is an aluminum single-seat aircraft. Its wooden, handmade propeller is driven by a 65-horsepower Volkswagen van engine.
Considered an “experimental light-sport aircraft” by the Federal Aviation Administration, the plane will have a top speed of almost 140 miles per hour and can perform limited aerobatics.
“That’s part of the thrill,” Marples says with a laugh. “Turn the plane upside down. Why not?”
A mechanical engineer who worked for many years as a boat designer, Marples has designed dozens of vessels, from a 10-foot wooden sailboat to a 110-foot power catamaran. He estimates he’s sold over 1,000 boat plans in his career. His vessels operate across the world today, from Hawaii to Saipan in the Pacific Ocean, and from Florida to Portugal in the Atlantic.
While designing boats was his career, his love of flying emerged 30 years ago when he was given a few hours of flight time with a pilot as a gift. Ever the engineer, Marples looked over the plane on his first flight and had an epiphany: “I said, ‘Jeez, I could build this.’”
He built two planes while living in Washington state, and then a third while living in California.
When Marples starts talking about flying, his eyes light up under his bushy gray eyebrows.
“It’s really a thrill to fly and realize you’ve left the ground in a machine of your own making,” he says. “It’s amazing. You enter a cloud and you are in total whiteout. And then you come out the other side and — poof — you are in sunlight again. I’d go above the clouds and listen to classical music with noise-canceling headphones. It was as close to heaven as you could get.”
At their home in the rural town of Penobscot, Marples and his wife, Robin Jettinghoff, park their cars outside their two-bay garage — the nearly finished plane takes up one bay, while the other houses two workbenches, a drill press and a table saw.
The plane sits on a modified boat trailer. The detachable wings sit off to the side and will be transported in cradles alongside the fuselage on top of the boat trailer. Once the plane is at an airfield, Marples will bolt the wings to the fuselage.
Marples bought the plans for the plane, which consist of about a dozen hand-drawn pages of schematics, from Thatcher Aircraft based in Pensacola, Florida.
“Some of the airplanes you build from kits, they fly well, but they’re ugly,” said Glen Bradley, president of Thatcher Aircraft. “But this one looks good. We call that, ‘ramp appeal.’”
Bradley estimates there are between 80 and 100 of the CX4 aircraft around the world today. One of their selling points is their affordability, he says. Plans cost around $500, and the entire plane can be built for less than $20,000.
Plus, he says, unlike other aircraft, the CX4’s Volkswagen engine runs on non-ethanol gas, which is available at many gas stations, rather than on expensive aircraft fuel.
Marples had to special order some of the plane’s parts, like aircraft-grade rivets and the handcrafted propeller made from maple. He found the plane’s cockpit instrumentation in a two-inch thick catalog from an aircraft supply company.
But much of the plane is built with off-the-shelf components. Screws, nuts, and paint came from a hardware store in Bucksport. The cockpit canopy opens and closes on kitchen drawer slides that Marples bought at Home Depot.
Marples found the plane’s sheet metal — a mix of marine alloy and aircraft aluminum — at Maine suppliers in Bangor and Skowhegan. To bend the aluminum into shape, he used a friend’s sheet metal brake tool in Blue Hill.
To Marples, building a plane is as straightforward as cooking. “If you can read, you can cook,” he says.
Marples fondly remembers learning in college how to rivet pieces of metal together. He admits that some of his ability to build machines is in his blood. His grandfather was an engineer at a steam plant in England who, Marples said, could diagnose the problem with a machine by laying his hand on it and listening.
“I think I inherited some of that,” says Marples, who emigrated from Great Britain to the United States at six years old.
For now, Marples is putting the finishing touches on his plane and hopes to fly it in the spring, possibly out of Belfast, which has a chapter of the Experimental Aircraft Association. As for what he’ll build next, it’s anybody’s guess.
“I’ve often thought I need a bumper sticker that says, ‘Stop me before I build something else,’” he says.
