John Bortz was among the scientists who worked on improving the accuracy of Omega, an early global radio navigation system used by ships and aircraft.
As he headed projects for more than two decades at The Analytic Sciences Corp., which formerly was in Reading, Dr. Bortz brought to the task a background in aeronautics and astronautics.
“Jack wasn’t just an average guy; he was a really special human being,” said Arthur Gelb, the company’s founder and president.
Dr. Bortz, who also was an ordained deacon of the Catholic Church, died Feb. 21 in Lahey Hospital and Medical Center in Burlington after slipping on ice and suffering a brain hemorrhage. He was 77 and lived in Acton.
Navigation systems played a big role in Dr. Bortz’s early training. While doing graduate work at MIT, he came up with what became known as the Bortz equation, which used geometric algebra to more accurately read a specific kind of navigation algorithm.
“It was just the theory he wrote his thesis on,” said his daughter Darcey Bortz Fahey of Weymouth, “but it was so profound.”
In the early 1970s, Gelb hired Dr. Bortz, who spent the rest of his career at Analytic Sciences.
“Jack’s background was perfectly suited to the technical work we did,” Gelb said.
Dr. Bortz was put in charge of several projects over the years.
“He had the skill set that allowed him to move from one kind of problem to another,” Gelb said.
Scientists whom Dr. Bortz supervised remembered him as a skilled tutor and mentor, not just on work matters, “but with personal stuff,” Alberto Calvo said.
“Everyone has that person who helped shape their career, and he was one of them in my case,” Calvo said.
Dr. Bortz, Gelb said, “left a trail of good work wherever he went.”
Gelb described Dr. Bortz as “one of those people who could stand toe-to-toe, nose-to-nose, and argue a point with all the facial expressions you need to make your point, because there was an actor in Jack.”
Born in Reading, Pa., John E. Bortz was a son of Bernard Bortz and the former Edna Long. After graduating from the Naval Academy in 1957, he was an Air Force navigator.
While working in Upstate New York, he met Elizabeth Davidson, and they married about 52 years ago.
He began working at the Charles Stark Draper Laboratory at MIT in 1961.
Dr. Bortz graduated from MIT with a master’s degree, having written his thesis on aeronautics and astronautics, and with a doctorate, his family said. He also graduated from Boston University with a master’s in business administration.
Fond of jokes, Dr. Bortz liked to tell one that spoke to his religious faith: “How do you get holy water? You boil the hell out of it.”
In 2000, two years after he retired from Analytic Sciences, he was ordained a deacon in the Catholic Church, serving St. Elizabeth of Hungary Church in Acton and St. Mary Church in Chelmsford.
Dr. Bortz officiated at the marriage of his youngest daughter and baptized four grandchildren, his family said.
He also volunteered at MCI-Shirley, often going to the prison at least once a week to counsel Catholic prisoners who wanted spiritual guidance.
“He just had such a flair for bringing people together and talking to them so that they didn’t feel overwhelmed or didn’t feel pressure,” Dr. Bortz’s daughter said of his church work.
He also had a talent for making sticky buns and would let the youngest person in the room punch down the dough. When interacting with children, he often crouched to their level to pay close attention to what they said.
“That’s the sign of a true listener,” his daughter said.
In addition to his wife and daughter, Dr. Bortz leaves four other daughters, Sandra of Kennebunk, Maine, Melanie Bortz Plitouke of Whitinsville, Tamara of Santa Cruz, Calif., and Christina Bortz DiPietro of Winchester; a son, John Jr. of Newburyport; two sisters, Joanne Young of Virginia Beach, Va., and Katherine Hancock of Bowling Green, Va.; a brother, Bernard of Allegan, Mich.; and 11 grandchildren.
A service has been held, and burial was in Woodlawn Cemetery in Acton.
After Dr. Bortz died, his relatives learned that he had a membership with a website that presented daily challenges aimed at keeping minds alert and agile.
“That’s just who he was,” Fahey said. “He wanted to always be sharp.”