SEATTLE — The first 747 jumbo jet, which changed the look of jet travel with its huge size and distinctive upper-deck hump, has flown into retirement, Boeing Commercial Airplane Group said.

The red-and-white jumbo jet rolled off the assembly line near Everett on Sept. 30, 1968, made its first flight on Feb. 9, 1969, and won certification on Dec. 30 that year.

Boeing has used the aircraft as a test plane for 21 years. Now, the “City of Everett” is being donated to the Museum of Flight in Seattle.

Pan American World Airways signed the first contract for 747s, ordering 25 for a total of $525 million. Today, that amount would buy four of the jets, Boeing said.

The test plane’s only break in service was from October 1983 to August 1986, when it was in storage in Las Vegas. It was then sent to Wichita, Kan., where it was used as a mock-up for two 747-200s that the Air Force will use to carry the U.S. president and his staff.

The plane had only 5,208 hours of flight time. That’s very low, considering a jet in normal commercial service flies 3,000 to 4,000 hours every year, company spokesman Tom Cole said.

“But it was tough stuff. They were always putting it into dives and stalls,” he said.

The plane, officially known as RA001, had a short final flight Wednesday: about 25 miles from Boeing Field in Seattle to Paine Field, where 747s are built near Everett.

There, its engines will be taken off and returned to Pratt & Whitney, which owns them, followed by some restoration work.

Eventually, the plane will be displayed at the museum’s restoration facility or at a new large-aircraft interpretive center the museum hopes to build at Paine Field, said Cindy Upthegrove, the museum’s special events manager.

About 800 747s are in service around the world, Boeing said.