Donald Nyrop, who led Northwest Airlines for a quarter century and built it from a safety-challenged regional airline into a globe-spanning carrier focused on safety and frugality, has died. He was 98.

Nyrop died Nov. 16 at his home in Edina, Minn., his family said. No cause was given.

Northwest was known for profitability after Nyrop became chief executive in 1954, even as other carriers faltered as the industry moved from a highly regulated, government-protected era into the early years of deregulation toward the end of his watch.

"Our father's commitment to Northwest Airlines, its employees and customers was unparalleled," daughter Nancy Nyrop Scherer said.

Nyrop was known publicly as a tightfisted executive who ran one of the best-run carriers in the country. But while warring at times with Northwest's unions, he was proud that despite several pilot and mechanic strikes, unionized workers never took a pay cut.

The former government lawyer scrimped on what he considered frills, operating from a bare-bones, near-windowless headquarters at Minneapolis-St. Paul International Airport. But he didn't scrimp on safety.

"He was an industry giant and he turned around Northwest Airlines," said Brent Baskfield, a retired Northwest executive. "He was very tough but he also was a gentleman."

Nyrop was born April 1, 1912, in Elgin, Neb. He graduated from Doane College in Nebraska in 1934 and George Washington University law school, then served as a staff lawyer for the forerunner of the Civil Aeronautics Board, which regulated the fledgling commercial airline industry.

He was an officer in the Army Air Forces during World War II and eventually rose to chair the aeronautics board. As a regulator, Nyrop sifted through the debris of a Northwest crash and was a critic of the carrier before he signed on to run the company.

Nyrop worked with key Midwest members of Congress and regulators who had influence in the Eisenhower administration to overrule the State Department's recommendation that Pan Am Airways win the lucrative northern routes to Japan and elsewhere in Asia, according to Melvin Laird, the former Defense secretary who eventually joined Northwest's board.

Paul Soderlind, Northwest's former chief pilot for technical operations, said Nyrop was driven by economy and safety.

"He wouldn't spend a nickel unless he was sure it would make a dime," Soderlin said in 1984. "I think he had an acute understanding of safety."

Chuck Easley, a onetime president of the machinist's union, once said Nyrop "could keep track of what the janitor was doing as well as what the pilot was doing and sniff out the most economical way to do the job. There was no glass in the building, no carpet on the floors, and he was proud of those kinds of things. I have no problem with that."

But it bugged some people. Perhaps the most infamous incident was when Nyrop, convinced that office employees were dawdling and reading newspapers, ordered the doors taken off the men's room stalls.

Northwest was acquired in 2008 by Delta Airlines.

In addition to his daughter Nancy, he is survived by daughters Karen and Kathryn; and eight grandchildren. He was preceded in death by his wife, Grace; and a son, William.

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