J. Leonard Frame helped put the Twin Cities on the global aeronautic engineering map thanks to his uncommon blend of technical expertise, entrepreneurial spirit and sales acumen.

FluiDyne, the company he launched in the 1950s, made inroads in markets from Sweden to Japan, earning a reputation for innovation and reliability. In 1993, when Frame was in his 60s, he reinvented the family business as a plasma heating company called Phoenix Solutions, remaining active on the job into his 90s.

Frame, a father of five, died in September. He was 95.

The University of Minnesota recognized Frame with an alumni achievement award and other honors over the years. He donated to the U’s aerospace engineering department and often met with students to share advice on starting and running a business, said Perry Leo, the department’s head. “Len was a really well-respected guy,” Leo said. “He turned FluiDyne into one of the leading wind tunnel manufacturers in the world.”

Frame grew up in South St. Paul, where he graduated from high school at 15. By age 19, he had earned an engineering degree from the U and enlisted to serve in World War II. After the war, he married Dorothy Mae Gadde, his partner until her death 66 years later.

Spotting a void in the market, in 1952 he founded Flui­Dyne Engineering, specializing in testing facilities for aerospace, such as wind tunnels. The company came to do work for NASA, Boeing and the U.S. Air Force. Frame set out to turn the company into a global presence, eventually delivering designs and facilities to clients in Sweden, Germany, Japan and other countries.

He had a leadership style that was at once hard-charging and personable. When mechanical engineer Gary Hanus debated whether to take a position with FluiDyne in 1987, Frame called him from a business trip in Taiwan to urge him to “make the right decision,” waking him up at 3 a.m., apparently unaware of the time difference. Hanus took the job — and stuck around for decades.

“He always made everybody who worked for him feel they were part of the family,” Hanus said.

Frame often entrusted workers with challenging projects and room to find their own way. Hanus said Frame had a knack for spotting flaws in his engineers’ designs, and he’d make bets that his hunch was right. (Hanus won such a bet only once.) But Frame was also a gifted salesman.

“I’d march into hell with him on a sales job because I knew he always had it by the throat,” Hanus said.

Frame’s daughter Susan of Minneapolis says even as he put in long hours and traveled often on business, he held family time sacred, routinely helping with homework and directing the church choir at Valley Community Presbyterian Church.

“He was a great dad who made time for everyone,” said Susan Frame, who worked as a receptionist at FluiDyne and later in Phoenix Solutions and at a now-defunct company Frame started in 2008 to repurpose mining waste.

Son Douglas Frame, a U graduate with a marketing and management degree, thought he would put in a short stint at the company in 1988 and never left, drawn by the spirit of innovation and the pride he felt in the family business.

“He lived to work; it was the engine that drove him,” said Douglas Frame, who lives in Plymouth and is president of Phoenix Solutions. “But I have many more memories of the time he and I shared doing things outside work we loved.”

In the early 1990s, as the aeronautical field remained plagued by uncertainty and a lack of federal investment, Frame stepped up efforts to diversify the business. In 1993, FluiDyne sold most of its assets to a St. Paul-based company and turned its focus to plasma heating systems. As Phoenix Solutions, the business once again gained global recognition, including for high-temperature heating technology to destroy hazardous waste.

In addition to children Susan and Douglas, Frame is survived by his second wife, Virginia Rovainen; daughters Peggy Oberfeld of Loretto, Minn., Julie Frame of Plymouth and Jennifer Takats of Palm Harbor, Fla.; and five grandchildren and three great-grandchildren. A service will be held at 2 p.m. Nov. 2 at Valley Community Presbyterian Church.