INSTRUCTOR PLT WITH STUDENT PLT TEACHING EMER LNDGS RUNS OFF THE END OF THE RWY WHEN WIND SHIFTS AND THEY LAND WITH A TAILWIND.

Narrative

I WAS IN THE PROCESS OF TEACHING EMER LNDGS TO A STUDENT PLT WHEN THIS INCIDENT OCCURRED. AT ABILENE; KS; ARPT (K78) WE WERE USING RWY 17; THE WINDS UPON TKOF WERE FROM 260 DEGS AT APPROX 5 KTS. DURING THE EMER PROC I CUT THE ENG AFTER TURNING DOWNWIND BEING IN A PLACE WHERE RWY 35 COULD BE MADE WITHOUT PWR. I TEACH TO BE SLIGHTLY LONG; BEING BETTER THAN SLIGHTLY SHORT. I HAD PERFORMED THIS MANEUVER TWICE THAT MORNING WITH OTHER STUDENTS AND LANDED IN THE SAME AREA OF THE RWY WITH NO PROB. DURING THE APCH WHICH WAS SLIGHTLY DOWNWIND; EVERYTHING LOOKED NORMAL. I HAD PICKED AN AREA OF THE RWY TO LAND WHICH ALLOWED DISTANCE TO STOP AND THE APCH BY THE STUDENT WAS WITH THESE PARAMETERS. AFTER TOUCHDOWN THE STUDENT STILL HAD CTL OF THE ACFT AND IT LOOKED LIKE A ROUTINE LNDG; WE ROLLED APPROX 500 FT WHEN I REALIZED WE WERE NOT SLOWING DOWN. AT THIS TIME I MADE A DECISION NOT TO ATTEMPT TO GAR DUE TO PWR LINES AND TREES AT THIS END OF THE RWY. I TOOK CTL OF THE ACFT AND ATTEMPTED TO STOP BY USING HVY BRAKING. IT WAS NOT UNTIL THE LAST 500 FT OF RWY THAT I REALIZED THE ACFT WAS NOT GOING TO STOP ON THE RWY. THERE WAS A HARD GND SURFACE OVERRUN WHICH I GUIDED THE ACFT ON. AT THIS TIME I THOUGHT I WAS OK. THE ACFT WAS ALMOST STOPPED AND WAS TRAVELING LESS THAN 5 KPH WHEN A HIDDEN DITCH APPEARED AND I DID NOT HAVE TIME TO TURN THE ACFT. THE NOSE OF THE ACFT DROPPED INTO THE DITCH CAUSING THE PROP TO STRIKE THE GND AND CAUSING DAMAGE TO THE PROP AND SLIGHT DAMAGE TO THE NOSE GEAR. IN RETROSPECT IT IS CLR THE WIND HAD CHANGED DIRECTION AND POSSIBLY INTENSITY CAUSING ME TO LAND WITH A TAILWIND. I DID NOT NOTICE THE WINDSOCK WHILE APCHING RWY 35; THE SOCK IS ON THE RWY 17 END OF THE ARPT. I ALSO DID NOT RECOGNIZE AN INCREASE IN MY GND SPD WHICH HAD OCCURRED. WITH THE COMBINATION OF A LONGER THAN NORMAL LNDG AND THE TAILWIND; THE ACFT WOULD NOT DECELERATE IN TIME TO STOP ON THE RWY.