The music icon is the subject of filmmaker Albert Maysles cinema vérité doc 'The Love We Make,' which is set to air Sept. 12 on Showtime.

BEVERLY HILLS -- Paul McCartney was on the tarmac at New York's JFK airport on the morning of Sept. 11, 2001. He was waiting to take off after a visit to the city.

“Out of the window on the right hand side of the airplane, you could see the Twin Towers. First there was a plume of smoke and then there was a second,” recalled McCartney. “I said that’s an optical illusion. It’s probably just some sort of little fire. Finally the steward came over to me and said, ‘Look, something serious has happened in New York and we’ve got to get you out of here.'”

They took McCartney off the plane first. “I don’t know why,” he said.

Unable to get back into Manhattan, he ended up on Long Island, in a hotel near the airport watching news footage of the terrorist attacks.

McCartney’s cathartic journey through the streets of New York and the planning and performance for the charity Concert for New York six weeks after the attacks is the subject of director Albert Maysles The Love We Make. The black and white documentary features cameo appearances from a bevy of music stars including Ozzy Osborn, Mick Jagger, David Bowie, Billy Joel and Pete Townshend as well as regular New Yorkers who come upon McCartney as he ambles through the traumatized streets of Manhattan. It will air on Showtime Sept. 12.

McCartney appeared at the Television Critics Association via satellite from Cincinnati, Wednesday’s stop on his concert tour.

“While I was out there [on Long Island] twiddling my thumbs,” he said, “I began to think, is there something we can do?”

McCartney first met Albert Maysles and his brother David Maysles (who died in 1987) when the brothers contacted them about documenting The Beatles' arrival in America in 1964.

“We said, ‘What do you want us to do? And I think it was David [Maysles] who said, ‘We want you to just ignore us. Well, we thought that was the best piece of direction we’d ever heard.”