The professional boxer went live Saturday to document a terrifying encounter he says he and his crew had just gone through after boarding a private jet ... which apparently failed to properly take off and crash landed back down to the airport grounds it was trying to leave.

Thankfully, it doesn't appear the aircraft got very far up before coming back down to Earth -- because Gervonta and co. seemed more or less okay ... with their health and bodies intact.

That's not to say Gervonta wasn't feeling some hurt afterwards -- on his live feed, he noted that his booty was aching like no other ... this while he wrapped his feet in gauze. He's pretty jovial about the whole thing, which is great to see, but this could've easily been way worse.

GD also gets some shots of the downed plane, and it sure looks like something went wrong internally. There were also fire engines that showed up on the scene to evaluate the damage and tend to anyone's injuries. Again, though, most everyone seems to be fine ... which is absolutely incredible, because it appears there were even children aboard, based on a photo Gervonta posted shortly before getting on. His video doesn't capture any kids, though.

It's unclear what exactly caused the malfunction -- but you can hear Gervonta and his friends speculate on what happened ... seems like there might've been some overheating of some sort. They also appear to be discussing some of the flight maneuvers the pilot(s) were using in the air ... and the group seems to think that may have attributed to it going down.

We're trying to get a hold of Gervonta's team for more answers.