Classical ballet has never been my cup of tea. I however appreciate the efforts made by ballet dancers to annihilate gravity (most contemporary ballet is comparatively down-to-earth, in the original meaning of the term).
While such efforts are vain, photography (still shots) manages to make such illusions more credible. Besides, ballet is an interesting subject for developing photographic skills (anticipation, manual focussing skills...) with a fair guarantee of pleasant results, after having culled those 90% of missed shots. Remember that ballerinas only want to look good, and have a narrow understanding of what "looking good" is all about.
The titles of the thread is obviously a pun on the other BIF (like "birds"), which is another photographic genre. With ballerinas at least, you'll shoot in the dry.
With "in flight", I do not necessarily invite to display shots where no body part touches the dance floor. Just those where indeed g seems to be much less than 9.81 m/s².
Df, 24-70/2.8 at 24mm and f/5.6, 1/100s