A functioning World War I-era gun was recovered during a search of a flier’s luggage at JFK Airport, authorities said Friday.

Philip Saada, 58, of Deal, NJ, was stopped after a TSA agent at an ­X-ray-machine spotted the revolver — circa 1910 or 1920 — in his carry-on luggage around 7:45 a.m., sources said. Port Authority Police arrested him.