For former pilots who once flew the bombers in Europe and the South Pacific, it is a chance to relive the war in their minds and to share stories with wide-eyed grandchildren.
For others, it is a chance to see a piece of history as the world prepares to celebrate the 50th anniversary of D-day Monday.
A B-17 Flying Fortress and the only fully restored, flying B-24 Liberator are touring the United States, making several stops in California.
A trip to Normandy for this week's ceremony was planned, but no corporate sponsor could be found to finance the $125,000 per plane cost of the trip, said Bob Collings, who established a nonprofit organization to restore the vintage aircraft.
"It's not like the high-profile sponsorship that race cars enjoy," Collings said. "It's tough."
The planes are owned and operated by the Collings Foundation of Massachusetts. They make more than 130 stops each year across the United States.
Several B-17s remain in flying condition. Some of them were seen a few years ago in the movie "Memphis Belle," which re-created a famous World War II bombing mission.
The B-24 bomber on tour is a replica of a plane, nicknamed the "All American," that served in World War II. Gunners on the original plane shot down 14 enemy fighters in a single raid over Linz, Austria, on July 25, 1944.
The plane was lost on Oct. 4, 1944, when it was shot down over Yugoslavia. All of the crew survived.
The B-24 on tour was built in 1944 by Consolidated Aircraft in Ft. Worth, Tex. It flew in the Pacific until the war ended. Abandoned in India, it served as a patrol bomber for that country from 1948 to 1968.
It cost more than $1.3 million to restore the B-24, Collings said.
About a third of the skin and more than 400,000 rivets were replaced, along with a mile of control cable, all of the electrical wiring and 5,000 feet of new hydraulic lines.
Collings says the B-24 is the only such plane that is fully restored and still flying. It has been barnstorming across the United States since 1989, and made its 500th stop in February.