Airplane enthusiasts mourn the end of the Boeing 747 double-decker jumbo jet, premiered in 1970, and Delta Air Lines gave them a chance to take a ride on some of the aircraft’s final routes.

The plane fell out of favor as more fuel-efficient aircraft came on the scene. Last month, United retired its last 747 with a 1970s-themed flight from San Francisco (SFO) to Honolulu (HNL), and Delta follows suit.

Last month the airline announced its last 747 plane will retire at the end of 2017, the last operated by any U.S. passenger airline. The plane will only fly Detroit (DTW)–Seoul (ICN) until then, and the final regularly scheduled service will leave Detroit Dec. 15.

The plane will go on a “farewell tour” from Detroit to Seattle (SEA) to Atlanta (ATL) to Minneapolis-St. Paul (MSP), Dec. 18–20. A few customers will join the otherwise employee-only flights using their Delta SkyMiles. The online auction ended Dec. 1, at 9 p.m. EST. The bids reached as high as 321,000 miles.

Delta employees and retirees can buy tickets for these flights, and proceeds go to the Airloom Project.