Travis Barker had a momentous day … flying for the first time since the deadly plane crash 13 years ago that killed 4 people and left him with third-degree burns on 65 percent of his body.

Travis and GF Kourtney Kardashian boarded a plane in L.A. Saturday … and it had to be a terrifying moment for the Blink-182 drummer who had vowed never to fly again after the crash that took the life of 2 close friends, Charles “Che” Still and Chris Baker, along with the 2 pilots. DJ AM survived the crash but died a year later of an overdose.

Travis understandably seemed hesitant … he and Kourtney, along with Kris Jenner and Cory Gamble, were headed to Cabo, but Travis was an hour late. It’s unclear if he was just delayed or had second thoughts, but it must have been gut-wrenching for him.

Years before the crash, Travis was terrified of flying, and just before getting on the ill-fated jet, he called his dad and said he had a bad feeling about the flight. Although he vowed never to fly again, he recently softened his position and said he might give it another try.

To understand the gravitas … Travis had multiple surgeries and skin grafts and spent months in a burn unit in tremendous pain. So, getting on a plane again must have been unbelievably emotional and, frankly, scary.

That he did, on Kylie’s private jet, and the group left for a vacay in Mexico.

All was well, and they’re now safely ensconced in Cabo.