DURING A PRE SOLO DUAL INSTRUCTION FLT; THE STUDENT LANDS NEAR THE R SIDE OF THE RWY AND THE INSTRUCTOR TELLS HIM TO CORRECT BACK TO CTRLINE WHICH HE DID NOT DO. HE IS TOLD TO GO AROUND AND ADDS FULL PWR AND THE ACFT HEADS FOR THE L SIDE OF THE RWY WHEREUPON THE INSTRUCTOR TAKES CTL OF THE ACFT. IN THE MEANTIME THE STUDENT REDUCED PWR AND THE ACFT CRASH LANDS OFF THE L SIDE OF THE RWY DAMAGING THE R WINGTIP AND AILERON.

Narrative

I WAS INSTRUCTING A STUDENT IN THE LNDG AND LNDG FLARE. THE STUDENT WAS JUST GETTING READY TO SOLO ON HIS NEXT FLT. WHERE THE INCIDENT TOOK PLACE: MY STUDENT FLARED ON THE RWY CTRLINE AND DRIFTED TO THE R ABOUT 20 FT WHICH PUT US ABOUT 10 FT FROM THE RWY EDGE ON THE R SIDE. INSTRUCTED HIM TO GET BACK TO THE CTRLINE WHICH HE DID NOT DO. I INSTRUCTED HIM TO DO A GAR. HE ADDED FULL THROTTLE AND STARTED A L TURN BACK TO THE RWY CTRLINE. HE DIDN'T TURN AGAIN TO PARALLEL THE CTRLINE; INSTEAD KEPT FLYING TO THE L. I THEN TOOK CTL OF THE ACFT AND TRIED TO GAIN CTL OF THE GAR. THE STUDENT ACTUALLY HAD INITIALLY ADDED FULL PWR AND THEN TOOK SOME PWR OUT WHICH CAUSED US TO DSND. I RECOGNIZED THAT A STALL WAS IMMINENT AND LOWERED THE NOSE. MY STUDENT REALIZED THAT WE WERE DSNDING AND ADDED FULL PWR BACK IN. THE ADDITION OF FULL PWR WAS ENOUGH TO KEEP US FROM IMPACTING THE GND TOO HARD. THE RWY EDGE SLOPED DOWN AND THE R WING SCRAPED THE GND; DAMAGING THE R WINGTIP AND R AILERON. THIS INCIDENT COULD HAVE BEEN AVOIDED BY MYSELF (CFI) KEEPING MY HAND ON THE THROTTLE TO MAKE SURE IT WAS PUSHED IN ALL THE WAY. THIS WOULD HAVE KEPT US FROM DSNDING DURING THE GAR. ALSO; MORE ACTIVE USE OF THE RUDDERS AND TAKING CTL OF THE ACFT SOONER COULD ALSO HAVE KEPT US ON THE RWY OR OVER THE RWY ASPHALT. NEITHER PLT (STUDENT) NOR CFI WERE INJURED.