A BEAM FAILED IN THE MAIN LNDG GEAR.

Narrative

AFTER NORMAL LNDG; DURING ROLLOUT (ON A B727) WE HEARD A BANG AND FELT A SLIGHT YAW IN THE STEERING. THIS OCCURRED AT APPROX 80 KTS. WE CLRED THE RWY. WE THOUGHT MAYBE A TIRE HAD BLOWN AND ASKED THE TWR TO SCAN THE RWY FOR DEBRIS. NONE WAS RPTED. TAXI SEEMED NORMAL; SO WE PROCEEDED TO THE GATE. UPON INSPECTION; WE FOUND THE R MAIN GEAR ASSEMBLY HAD FAILED. I OBSERVED THAT; AT THE POINT OF SHEAR; THERE WAS ONLY ABOUT 10 PERCENT FRESH BRAKES. APPARENTLY THERE HAD BEEN A FRACTURE IN THE GEAR ASSEMBLY FOR SOME TIME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS A LITTLE VAGUE AS TO EXACTLY WHICH PART OF THE LNDG GEAR FAILED. IT WAS APPARENTLY A HORIZ BEAM CONNECTING THE FORE AND AFT ATTACH POINTS. THE FAILED BEAM WAS PUSHED UP TO THE UNDERSIDE OF THE TOP WING AND SPOILER SURFACES LIFTING THE SPOILERS. THERE WAS VERY LITTLE FURTHER DAMAGE. THE LNDG GEAR ASSEMBLY HAD BEEN INSTALLED ONLY 3 YRS IN THE ACFT. THIS WAS ONLY THE SECOND FAILURE OF THIS TYPE IN THE B 727-200 KNOWN TO THE RPTR.