Joseph KillpatricK 1933 - present In the 1960s, the Honeywell engineer helped develop ring laser gyroscopes (RLGs), which now are used for guidance and control in nearly all military and commercial aircraft. (The Minnesota Star Tribune)

Joseph Killpatrick doesn't fly or build airplanes. But he joined four fliers and an airport operator inducted in the Minnesota Aviation Hall of Fame at a Saturday night banquet in Bloomington.

That's because Killpatrick, 85, developed revolutionary Honeywell ring laser gyroscopes in the 1960s — vital gizmos known as RLGs that are used today for guidance and control in nearly all commercial and military aircraft, not to mention the Space Shuttles, Mars rover and the probe that explored Pluto.

"He might be considered an unlikely candidate," said Armand Peterson, a retired Honeywell engineer who nominated Killpatrick. "The general public and business community in Minnesota know almost nothing about RLGs, but when they arrive safely at their destinations in a commercial jetliner, they can thank Honeywell's RLGs."

Peterson has received state grants to conduct oral history research about the development of laser gyros. And a display on Killpatrick's innovations is in the works for the Minnesota Air National Guard Museum.

"The RLG changed the world of navigation," said Peterson, insisting Killpatrick's device is "the most significant aviation ... product to come out of Minnesota" and arguably "the most significant technical product" created in Honeywell's history of making control devices.

And if you think that's just Honeywell boosters bragging, listen to retired Boeing engineer Mel McIntyre. He says all the company's commercial airplanes use the laser gyros, which he calls "an industry first and ... a testimony to the vision, courage and skill" of Killpatrick's team of research engineers.

Even with the advent of global positioning systems (GPS), Killpatrick's gyros remain pivotal, McIntyre said, "as the two are now used together to create a blended navigation solution which provides both extremely high precision and integrity for all phases of flight." He said the Honeywell gyros reduced costs and improved reliability 20-fold, eliminating the pre-1970 need for in-cockpit human navigators. "An outstanding achievement," the Boeing expert said. "And they are still made in Minneapolis!"

Killpatrick, who retired in 1999, is as unassuming as the modest white house he's shared with his wife of nearly 63 years, Carole, in St. Anthony Village. They paid $21,900 for the place in 1961 and raised three kids there. With 44 patents to his name, you'd think Killpatrick could have moved up into plusher digs.

"We didn't make a lot of money, but it's nice to know your career made a difference," he said in a telephone interview. "A lot of people thought I was crazy, but I'm an optimist and, at times, a realist. Things turned out much better than I ever could have predicted."

The oldest of three brothers, Killpatrick was born in 1933 in southern Illinois. He stayed nearby to study electrical engineering at Millikin University and the University of Illinois.

He met Carole in chemistry class — "I had to wait four months for our first date because she was booked up," he said. They wed in 1955 and honeymooned at Niagara Falls. Romance gave way to engineering when Carole agreed to let Joe tour the hydro-electrical power plant.

They drove through Canada to Minneapolis, where Killpatrick had landed a job at Honeywell. Taking math and science classes at the University of Minnesota, he promptly delved into the fledgling field of lasers, which were mostly cutting tools in the mid-1950s.

Using gaseous neon and helium lasers, Killpatrick put together a team to develop laser gyros — with backing from the Defense Department. By 1966, they won a $110,000 contract from the Navy to develop a prototype for launching missiles from ships. They tested their contraption on a Honeywell plane flying to a naval testing base in California — prompting a write-up in Aviation Week, an industry magazine Killpatrick calls the "bible of our industry."

They were on their way — but the flight would be rocky.

"We struggled for seven years to get contracts," Killpatrick said. "Gyros would fail, we had trouble making deliveries, but we were constantly pushing through the tough times."

His engineering prowess was matched by his sales savvy. Honeywell spent $50 million in a 15-year development span, with NASA and the Defense Department footing half the bill.

"Convincing Honeywell management that a simple mechanical approach could solve a very sophisticated electro-optical problem was a touch of Joe's wonderful salesmanship," said Ted Podgorski, a retired Honeywell senior engineer.

By the mid-1970s, Killpatrick's quest to develop small, durable, reliable laser gyros began paying off. Boeing awarded Honeywell a major contract in 1978 and production began — 15 years after that first naval breakthrough.

"A major revolution took place in the worldwide commercial and military navigation business with Honeywell disrupting entrenched manufacturers and becoming the dominant player," Podgorski said.

Killpatrick went on to develop a digital gyro that talks to modern computers — all contained in a device Podgorski says is the size of a hockey puck.

"It's actually a little bigger than a hockey puck," corrected Killpatrick, who ought to know. He and Carole have had Gophers hockey tickets for 50 years.

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com. His new book looks at 1918 Minnesota, when flu, war and fires converged: tinyurl.com/MN1918