THE NOSE GEAR COLLAPSED ON AN SMA ON ROLLOUT AFTER NORMAL TOUCHDOWN.

Narrative

MAKING FINAL APCH ON RWY 34; PIERCE COUNTY; THUN FIELD (1S0). FULL FLAPS; AIRSPD ON SHORT FINAL 67 KIAS. ON TOUCHDOWN STALL WARNING HORN WAS GOING OFF JUST AS MAIN GEAR TOUCHED DOWN 57 KIAS. AS NOSE GEAR TOUCHED DOWN; ACFT BEGAN MOVING TO THE L OF CTRLINE. I APPLIED R RUDDER PEDAL; BUT THE ACFT DID NOT RESPOND. FURTHER APPLICATION OF R RUDDER AND BRAKE DID NOT GIVE ANY ACFT STEERING CTL. AS THE ACFT WAS ABOUT 30 FT FROM LEAVING RWY; BOTH BRAKES WERE APPLIED. THE ACFT LEFT THE RWY AT MID FIELD; BTWN RWY 34 AND TAXIWAY; CAME TO REST WITH NOSE GEAR COMPLETELY COLLAPSED; PROP WAS BENT; LOWER COWLING DAMAGE. NO INJURIES OCCURRED. UPON INSPECTION; I FEEL THE CAUSE WAS IMPROPER WELD PENETRATION OF UPPER L SUPPORT TUBING AT UPPER NOSE GEAR SLEEVE; TUBE SEPARATED FROM SLEEVE ALLOWING NOSE GEAR TO BE AT TOP TO SWING TO THE R ALLOWING WHEEL AND TIRE TO SWING L; CAUSING NO STEERING CTL; AND ACFT TO MOVE L. AT TIME OF LOSS OF CTL; ACFT WAS TRAVELING 40-45 KIAS. THE UPPER L SUPPORT BAR ON THIS ACFT HAS HAD A HISTORY OF SEPARATION AND BEEN REPAIRED SEVERAL TIMES. PROPER WELD PENETRATION BTWN UPPER CTL BAR AND NOSE WHEEL SUPPORT TUBE WOULD HAVE PREVENTED SEPARATION AND NOSE WHEEL COLLAPSE. WIND CONDITIONS: 290 DEGS AT 5 KTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: AN ATTEMPTED CALLBACK PROVED FUTILE AS THE RPTR IS OUT OF TOWN UNTIL MID NOV. THE QUESTION IN THIS ANALYST'S MIND: IS THIS FAILURE PECULIAR TO HIS ACFT OR TO ALL ACFT OF THIS TYPE?