Introduction:
I was trying to kill a zombie while flying in creative, when I realized that no "sweep" particle was being played. I thought that this was the bug, but after further review, it appeared that I could not use sweep attack while in the air. Then, I tested it while jumping. The sweep attack did not work then either.

What I expected to happen...:
1st) Sweep Particle Played
2nd) Sword Sweep Work While Flying
3rd) Sword Sweep Work While Jumping

What Actually Happened...:
1st) No Sword Sweep Particle
2nd) Sword Sweep Did Not Work While Flying
3rd) Sword Sweep Did Not Work While Jumping

Gamemode does not affect this, neither does the type of sword, nor whether you are moving up or down, nor what type of mob you hit.

Steps to Reproduce..:

1. Spawn/Find a Mob
2. Jump or Fly In Creative
3. Attack the Mob with a Sword