A lifelong interest in airplanes has led this aviation enthusiast to some pretty interesting places and in touch with some very well-known people. And he’s done it all from his home base in Rockford.
Mark Clark loves all things aviation.
Since he was a teenager, Clark has flown historic airplanes and general aviation airplanes. He’s traveled by hot air balloon, the Concorde, Goodyear Blimp and amphibious airplanes.
Clark started hanging out at airshows and gravitated toward military airplanes. He got a part-time job as an airplane mechanic apprentice, earned his solo flying license at age 16 and his private flying license at 17. In fact, Clark earned his flying license before he got his driver’s license.
“I’m just a regular guy who’s had a fantastic opportunity due to my passion for historic airplanes,” Clark says. “This industry has given me many connections that have opened doors for me.”
For more than 40 years, Clark has been buying and selling warbirds – ex-military airplanes that have been used by various military branches. Clark’s business, Courtesy Aircraft, sells about 40 warbirds a year. The remaining portion of the business is general aircraft sales, such as corporate planes that are used for business purposes.
Courtesy Aircraft has three employees, including Clark. It’s based in a 13,000-square-foot hangar Clark bought in 1991 and is tucked away near a long runway at the Chicago Rockford International Airport. Clark says the airport is ideal because it’s capable of handling any type of aircraft, and its location in the center of the country makes it a great place to do business.
“We’re not selling Toyota Camrys; we’re selling 60-year-old airplanes with a lot of history,” he says. “My job is to educate our customers – where to find parts, how to fly them. There’s a lot to learn about owning one of these planes.”
Clark followed in his father’s footsteps when D.M. Clark started a Cessna aircraft dealership in 1957.
“My dad has been in the automotive business since the late ’40s,” he says. “At the time, he liked buying and selling things, and he eventually got into airplanes.”
The younger Clark took notice of his father’s activities as a teenager, and when he got his hands on a book about aviation he became hooked.
“I was in high school when I started tracking down how many of these airplanes still existed,” he says. “It was amazing that a few of those airplanes from the 1940s were still around.”
A Rockford native, Clark graduated from Guilford High School in 1969 and went on to earn a marketing degree from Bradley University, in Peoria, Ill. He returned to Rockford and worked as a mechanic apprentice, later becoming a corporate pilot for a couple of years.
His interest in old planes intensified in 1975 when he started working for his dad washing airplanes. The warbird business took off about a year later. When Clark bought the business from his father in the late 1970s, he gave his full attention to buying and selling planes such as World War II and Korean-era ex-military trainers, fighters and bombers such as the T-6/SNJ Texans, P-51 Mustangs and B-25 Mitchells.
“I love the history of the warbirds,” he says. “I was always intrigued about what happened to those World War II fighter, bomber or trainer planes after the war.”
Mike Hall met Clark in 2006 when Hall served as president and CEO of the Wings of Eagles Discovery Center in New York. Hall flew fighters for nearly three decades of Air Force service, retiring as a Major General in 1995. Hall says the museum found itself in financial straits at the time and hired Clark to help the organization sell off a B-17 World War II bomber for $3.5 million.
“What he’s doing is buying and selling, but the impact of what he’s doing goes far behind the transaction,” says Hall. “He brokered the deal incredibly quickly in what was required to keep us in business. We had an impossible financial situation, and this deal was important to our future. No one in the country knows airplanes and the market better than Mark.”
Many of Clark’s customers are doctors, lawyers, astronauts or members of the Forbes 400 list. Some are celebrities: Clark once sold a plane to actor Tom Cruise. But most of his clients prefer to fly under the radar, so to speak.
“It’s a passion,” Clark says. “These are collectors who enjoy the sights and sounds of airplanes, who enjoy the history of the aircraft. This is no ordinary hobby.”
It’s also an expensive pastime. According to Clark, the cost to own and maintain a warbird can range from $35,000 for a J-3 Cub to in excess of $2 million for a military World War II fighter P-51 Mustang. Prices, Clark says, have doubled in the past 15 to 20 years.
Suzanne and Gene Hitchcock of North Oaks, Minn., owned a small aircraft restoration business dating back to the 1970s. In 1997, they worked with Clark to purchase a North American T-28 that had a long history of combat use as a trainer for the Air Force and Navy and was flown in Vietnam. When Gene passed away two years ago, Suzanne decided to shutter the family business and contacted Mark, who found a buyer for the vintage Warbird within three weeks.
“It was such a smooth deal,” Suzanne says. “Mark is easy to work with and always kept me in the loop. He just handles everything so well.”
Deals can be complex in nature. It can take anywhere from a couple of days to several months to negotiate a contract. When the seller, broker and buyer all live in various parts of the country or world, it takes serious coordination to get all interested parties together. The process has changed over the years.
“We used to have about 12 planes on-site, but thanks to the internet, half the planes we sell don’t come to Rockford,” he says.
Clark has sold planes over the world, in places including France, Australia, South Africa, Switzerland and Germany. He once traveled to Honduras and bought nine T-28 trainer airplanes from the Honduras government.
“I can close my eyes, put my finger on a map and find a client within 50 miles of that spot,” he says.
That includes Tom Duffy, a trial lawyer who lives in Delray Beach, Fla. Duffy bought his first plane from Clark 20 years ago and has bought and sold about a dozen war and civilian planes from him. They’ve since become friends.
“He’s the preeminent broker of these warbird planes,” Duffy says. “He knows his inventory impeccably, and he’s unbelievably honest and straightforward about the market and what you should expect. I’m a big fan of his.”
Over the years, Clark has shared his love of aviation with others, especially younger enthusiasts. Clark has given tours of his hangar to high school students and often sponsors aviation events geared toward students.
“There are great opportunities for young people to get involved in aviation,” he says. “There’s a real need for pilots and mechanics, and we’re blessed to have many great aviation facilities in the area.”
For his efforts, Clark has often been honored by his peers. He holds the Federal Aviation Administration’s Wright Brothers Master Pilot Award and is a longtime organizer of the National Warbird Operators Conference. In 2020, he was inducted into the Experimental Aircraft Association (EAA) Warbirds of America Sports Aviation Hall of Fame.
“For many warbird owners, Mark is more like a “matchmaker,” bringing would-be custodians/pilots and these historic flying treasures together as he helps turn a dream for many would-be warbird owners into reality,” says Jim Busha, EAA vice president of publications, membership, marketing and retail.
“A debt of gratitude is owed to Mark because, without his tireless dedication to keeping these warbirds flying, our skies would be void of these flying warriors.”
Despite his hectic schedule, Clark manages to fly about 150 hours a year. He once flew five types of planes before noon in a single day, but says he’s not quite that adventurous anymore.
Still, he doesn’t expect to hang up his wings anytime soon.
“I can’t turn off the switch,” he says. “I take it easier than I did 20 years, but as long as I’m physically capable, I’m going to keep on going.”
D.M. Clark passed away 12 years ago, but he was able to witness much of his son’s aviation success.
“My dad got me started on this journey,” Clark says. “We shared the passion, and he was pleased with what we’ve done with the company that he started. I know he would be proud.”