Lance Bass says the only way a potential *NSYNC biopic is ever getting off the ground is if he’s a producer … and he’s already got an idea for how to tell the band’s story.

We got Lance at LAX on a rainy Friday afternoon, and our photog asked him about a much-talked-about biopic that hasn’t quite gotten off the ground.

Lance says it may well happen down the line, but he explains why there are some major hurdles to clear.

We broke the story … the biopic stalled because the guys just weren’t sold on the pitch or the producer behind it. Justin Timberlake‘s manager brought the idea to the band after “Fast & Furious” producer Neal H. Moritz started shopping it around.

But Lance is doubling down … it’s a non-starter unless he’s a producer.