Flavor Flav's got airline passengers in their full upright position ... 'cause the dude flies so much he's basically a flight attendant -- quite literally.

The rapper shared a video where it looks like Southwest's has him on duty ... 'cause he's walking up and down the aisle handing out snacks to all the other passengers at 30K feet.

Check out the vid ... FF -- fully decked out in his 2024 Olympics apparel, complete with a custom watch hung around his neck -- seems happy to help out the crew, giving a "yeah, boy!"

People onboard took pics of the Public Enemy rapper and one of his clocks as he gave them their snacks ... not an experience many people are lucky enough to have.

Flav wrote in the caption of his recent X post he ran into some flight crew members while in Paris for the Olympics ... who told him he could pass out snacks and give the landing announcement during the flight.

No clip of the announcement ... but, knowing Flav, it's probably more hype energy than most fliers are used to getting on their flights.

Of course, Flav played an important role at the Olympics ... kicking off a 5-year sponsorship deal with the U.S. water polo teams -- both men and women -- prior to this year's games -- and partied with the women's team in Vegas post-Olympics.