ACFT DAMAGES GEAR ON SNOW BERM DURING APCH TO NON TWR ARPT.

Narrative

I WAS GIVING FLT INSTRUCTION TO A STUDENT PLT IN HIS ACFT; A PA-243-140; WE WERE PRACTICING TKOF AND LNDGS AT AN ICE RWY (B18) -- ACTON BAY; THE FIRST LNDG WAS OK; ON THE SECOND LNDG; WE HIT A GUST OF WIND ON SHORT FINAL. AS I WAS JUST ABOUT TO ADD PWR TO CORRECT FOR THE PROB; THE R-MAIN GEAR STRUCK A SNOW BANK AT THE RWY END; AS THE PLANE STARTED TO VEER R. I IMMEDIATELY TOOK CTL OF THE AIRPLANE; ADDED PWR; AND FLEW AWAY FROM THIS ARPT; AS WE DEPARTED SOMEONE ON UNICOM ADVISED THAT THE R-MAIN GEAR APPEARED DAMAGED. I DECIDED TO BRING THE PLANE BACK TO LACONIA (LCI); NH; I ADVISED UNICOM OF THE POSSIBLE GEAR PROB. I DID 2 FLY-BY'S SO THE ARPT MGR COULD ASSESS THE DAMAGE. HE REPLIED THAT IT WAS A SCISSOR-LINK THAT WAS MISSING. I SET THE PLANE ON THE ACTIVE RWY; TOUCHING DOWN SLOW; KEEPING THE R WING UP AS LONG AS POSSIBLE; THE WING SETTLED DOWN ON THE COLLAPSED GEAR THE PLANE VEERED R AND SKIDDED. THERE WAS NO INJURY NOR DAMAGE TO THE ACFT OR PERSONS. THE PLANE WAS MOVED OFF BY DOLLY AND TOWED TO A HANGAR.