So appearently you can stand in mid air with survival mode...

I think its a "crawling" bug? Like glitching into the Trapdoor Block... I will let the pictures talk, yes this is creative, but in the one I am actually flying in, is the one where I "crawl"... 
Steps to reproduce... Urgh this is a pain... I got it by accident and you cant really tell if you are in the bug while flying...
Pictures to display https://imgur.com/a/Vx8Taly 
Step one, Sprint towards the pressure plate
Step two time it right after you cross the height you would land on top of it so you actually would start "crawling" under the trapdoor
Step three retry a lot... its not that simple to get...

The actual reason behind this setup was standing on top of the pressure plate and walking towards the wall, than right clicking it so you fall through still walking forward would let you slip inside the one block gap in the wall