For me they always land on their feet, then realize they died.

@Kleiner's final Form
it's in the basegame, dragon's crashland for me all the time

Back in Skyrim before Special Edition, I had done this to the dragon sleeping on Autumnwatch Tower with a sneak knife stab straight to the snout. I had previously unlocked the "Backstab" perk that makes sneaking one handed weapon attacks do six times as much damage + "Assassin's Blade" which makes dagger attacks do fifteen times more damage.

I don't know if the perk effects overlap and stack but that dragon launched into the air and proceeded to swiftly crash into the ground leaving that long trench of dirt as seen here. Fortunately I saved just prior to doing this so I could make a video if I had do... or just do it over and over again for giggles.

Whats the mod that makes them crashland?