N487ER

The Flight Instructor (CFI) of the landing airplane (N5144H) said, the student pilot's landing was not stabilized and the CFI stated, "my controls" and assumed control of the airplane. However, according to the CFI, the student did not release the right rudder pressure and the airplane exited the right side of the paved portion of the runway, impacted a taxiway sign, and subsequently impacted an operating airplane on the adjacent taxiway. The landing airplane sustained substantial damage to the nose and left wing. The taxiing airplane sustained substantial damage to the right wing spar. Neither the pilot of the landing airplane nor the taxiing airplane reported any mechanical malfunctions or failures with their respective airplanes, prior to the accident that would have precluded normal operation of the airplane.