Post Malone rave the stage in England

Post Malone showed no signs of PTSD following his super scary airplane emergency this week -- he just hopped on another jet to the UK and owned the stage as usual.

The rapper/singer performed for the first time since his plane was forced to make an emergency landing at Stewart International Airport in New Windsor, NY Tuesday ... rocking out during day one of the Reading Festival at Richfield Avenue in England Friday.

Posty wore a black getup featuring his nickname along with "Let's Get Weird" embroidered on his shirt ... and didn't look like the frightening flight had any lingering effects on him.