Impact protection enchantment - elytra exclusive

My idea of this enchantment is a elytra exclusive enchantment.

This enchantment would have 4 levels like the others protection enchantments, It would work when you crashes into a wall with an elytra, the enchantment would reduce the damage taken.

It would be great to have it because currently the elytra only have 2 enchantment (without including the curses), being mending and unbreaking, I think it should be an elytra only so if you are "flying" with a trident and a chestptate it won't work.