Flight Mode

You can enter flight mode by double-jumping just like in Creative Mode. You can then fly omnidirectionally as long as you have energy, which is indicated by a progress bar at the top of the screen. Your energy depletes depending on how much you're moving, so hovering still or moving down doesn't deplete it!

You can switch to Glide Mode by double-jumping again, which will put you in standard elytra gliding even if you're not wearing elytra.

If you run out of energy, you'll be switched into Glide Mode and you must wait for it to recharge to half full. Energy recharges whenever you're not in Flight Mode, including when you are falling or in Glide Mode.

As long as your energy meter is green, you will not take fall damage.