Sanford McDonnell, a former boy scout who went on to work on the first atomic bomb before heading aerospace giant McDonnell Douglas, has died, according to Boeing.
McDonnell Douglas's former chairman and chief executive, known as Sandy, had been diagnosed with pancreatic cancer in November 2010 and died on Monday, aged 89, at his home in the St Louis suburb of Clayton.
"The people of Boeing (which bought McDonnell Douglas in 1997) extend our deepest sympathies to the McDonnell family, and join them in mourning Sandy's passing," Jim McNerney, chairman, president and chief executive of Chicago-based Boeing, said in a statement.
"Sandy's commitment to his colleagues and customers, his country and his community during his 40-year career and throughout his lifetime was extraordinary."
McDonnell, the nephew of McDonnell Aircraft founder James McDonnell, served as chief executive from 1972 and became chairman eight years later after his uncle's death.
Sanford McDonnell retired in 1988 and was succeeded by John McDonnell, a James McDonnell son who was serving as company president and chief operating officer.
John McDonnell later guided the corporation through its merger with Boeing and still holds a seat on Boeing's board of directors.
"Frankly, I feel vigorous enough to continue working full-time for several more years," Sanford McDonnell said in announcing his retirement more than two decades ago.
"But I've long believed that no one should remain in the top position at a major corporation much beyond the age of 65, and retiring now is a way of practising what I preach."
Princeton-educated McDonnell joined McDonnell Aircraft in 1948, after spending two years during the Second World War in the New Mexico desert playing a role in the top-secret Manhattan Project that developed the world's first atomic bomb.
With the company, McDonnell held various positions of increasing responsibility in the ensuing years, along the way helping develop the F-4 Phantom II fighter jet. He became vice president of project management in 1959, a member of the board of directors in 1962 and president in 1966.
He was elected a director of McDonnell Douglas - the military plane-maker famous for the F-4 Phantom, Saturn rocket and Mercury and Gemini space capsules - when the corporation was formed through the merger of McDonnell Aircraft and Douglas Aircraft of California in 1967. He was named the corporation's president in 1971 and chief executive the following year.
Under McDonnell's watch, McDonnell Douglas built the Skylab space station in 1973.
After retirement, McDonnell started what he called a "second career devoted to character development", serving as chairman of a character-education effort he founded in 1988 for St Louis-area schools and formerly called PREP - Personal Responsibility Education Process.
He also headed the board of the Character Education Partnership in Washington DC, a national organisation designed to develop moral character and civic virtue in young people.
A memorial service is planned for March 28 at the St Louis area's Ladue Chapel Presbyterian Church.