“I did!! This one is a lot bigger. It looks easily over 100 meters long! If a mass that large slams into the ground with the speed needed to catch up to a supersonic passenger plane…!”
[...]
It was as if the man had wanted that.
Immediately afterwards, a bluish-white blade of light extended from the dragon’s mouth and sliced its giant body two or three times.
[…]
The man had not sliced the dragon into pieces.
That would have left the pieces of that giant corpse to rain down on the switchyard. The countless flashes of that sword of light did not fully slice through the dragon’s body. He left the pieces attached like vegetables cut by a terrible cook.
All he needed was air resistance.
He needed to throw off the dragon’s balance.
Níðhöggr’s giant body could no longer maintain its orientation, so the direction of its flight greatly changed as if a giant invisible hand were moving it off course. The dragon now headed toward the river instead of the land and it crashed into the water, starting with its battered head. Water flew in every direction with incredible force and the rubber boat shook, but that was all. A hopeless situation similar to an asteroid strike did not occur.

Toaru Majutsu no Index New Testament vol.8 ch.4 pt.16