Put the summary of the bug you're having here

What I expected to happen was...:
For me not to crouch while flying.

What actually happened was...:
A very strange animation.

Steps to Reproduce:
1. Put on elytra.
2. Start flying and go into third person (use the fireworks to gain some height).
3. Press your "sneak" button and behold the demonic sight as your character awkwardly crouches while in a horizontal position!