Going, going, gone at the speed of sound.

A massive model of the Concorde that was part of a British Airways ad in Times Square from 1996 to 2001 (right) will be sold at auction by Bonhams next month.

At half the size of the actual supersonic jet, the 102-foot-long, 42-foot-

wide Concorde replica is one of the largest airplane models ever made.

Built for roughly $1 million and brought to the city on five trailers before being assembled in Times Square, the model has been sitting in storage at the Cradle of Aviation Museum on Long Island.

It’s expected to fetch somewhere from $100,000 to $150,000 when it goes on the block May 5, said Matthew Haley, Bonhams’ space-history expert.

Concorde service was discontinued in 2003.