A CESSNA T310R ON LNDG THE R MAIN LNDG GEAR COLLAPSED DUE TO THE FAILURE TO LOCK IN THE EXTEND POS CAUSED BY SHEARED BOLTS IN THE LNDG GEAR ASSEMBLY.

Narrative

ON LNDG ROLLOUT AT MORAINE ARPT (I73) I NOTICED THE R WING DIPPING FURTHER THAN NORMAL; ABOUT DOWN TO THE GND. I PROCEEDED TO INITIATE A GAR. WE HAD 3 GREEN (GEAR SAFE) LIGHTS ON DURING THE APCH TO LAND BUT NOW THERE WERE ONLY 2; RIGHT MAIN SHOWED UNSAFE. I TRIED RETRACTING AND EXTENDING THE GEAR AGAIN WITH ONLY 2 LIGHTS ILLUMINATING; STILL THIRD (R MAIN) SHOWED UNSAFE. I THEN RETRACTED GEAR MECHANICALLY AGAIN; THEN DID AN EMER GEAR EXTENSION. STILL 2 OUT OF 3 GREEN LIGHTS. I TRIED A FLY-BY OVER FLT OFFICE AND AN INSTRUCTOR RADIOED BACK THE GEAR LOOKED DOWN AND LOCKED. I TRIED ANOTHER LNDG BUT AGAIN THE R WING BEGAN TO FALL DURING ROLLOUT. I THEN WENT TO WRIGHT BROTHERS ARPT (MGY) TO TRY A SAFER LNDG ON THE LONGER RWY. STILL SAME DROP ON R WING. THEIR MECH ALSO LOOKED AT THE GEAR AS I FLEW BY LOW AND SLOW. I TRIED ONE FINAL ATTEMPT TO LAND WITH NO AVAIL. I THEN PROCEEDED TO DAYTON INTL (DAY). I DID 1 LAST TOUCH-AND-GO TO TEST THE R MAIN BUT HAD TO GAR AGAIN. I PROCEEDED ON A 3 MI FINAL; HELD THE AIRPLANE OFF THE RWY TILL APPROX 65 KTS; AND SOFTLY TOUCHED DOWN. JUST AFTER TOUCHDOWN I SHUT DOWN AND FEATHERED THE R ENG AND THEN DOWN CAME THE R WING. IT STRUCK THE RWY PULLING THE ACFT R OF CTR AND OFF THE RWY INTO THE GRASS. MECHS FOUND 2 BOLTS ON LNDG GEAR SHEARED.