The pilot of the airplane reported that, while landing in gusting crosswind conditions, he flared too much, and the nose of the airplane pitched up. Subsequently, the airplane porpoised about 3 times on the runway, veered left, exited the runway, and nosed down.
The airplane sustained substantial damage to the engine mount and fuselage.
The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.