The solo student pilot reported that on his second supervised solo landing touchdown, the airplane landed flat and firm. He further reported that the airplane "roared" then veered off the runway to the left, and stopped abruptly after the nose wheel became stuck in mud.

The student pilot further reported that he may have accidently advanced the throttle after he was pushed forward during the flat landing.

According to the student pilot there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

A postaccident examination revealed substantial damage to the firewall.