IN A VELOCITY RG; AS THE NOSE GEAR WAS LOWERED TO THE RWY; A VIOLENT OSCILLATION OCCURRED AND THE NOSE GEAR BROKE OFF; CAUSED BY A CRACKED NOSE STRUT.

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AS I LOWERED THE NOSE TO THE RWY A VIOLENT OSCILLATION BROKE OUT IN NOSE GEAR. IT BROKE OFF AT THE FUSELAGE. FSDO COULD NOT BE REACHED TO GET PERMISSION TO MOVE ACFT. OSCILLATION HAD OCCURRED IN THE PAST AND REINFORCEMENT HAD BEEN ADDED TO THE NOSE GEAR BULKHEAD. NOSE GEAR AXLE; WHEEL; FORK AND STRUT HAD BEEN INSPECTED. A CRACK IN THE HEAT TREATED STRUT WAS NOT VISIBLE UNTIL IT BROKE COMPLETELY. HAVING A PAX IN THE FRONT SEAT APPARENTLY CHANGED THE CASTER ANGLE ENOUGH TO ALLOW SHIMMY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THIS NOSE GEAR HAD A SLIGHT NOTICEABLE VIBRATION THAT RESULTED IN THE BULKHEAD SUPPORTING THE LNDG GEAR STRUT TO CRACK. THE RPTR SAID THE BULKHEAD CRACKS WERE REPAIRED AND THE BULKHEAD REINFORCED. THE RPTR STATED THAT AFTER THE NOSE GEAR BROKE IT WAS DISCOVERED THE FACTORY THAT MADE THE CHROMALLOY STRUT HAD BENT THE STRUT INCORRECTLY CAUSING THE VIBRATION AND CRACK. THE RPTR SAID THE ERROR WAS ADMITTED BY THE FACTORY. THE RPTR STATED INSPECTION OF THE ENTIRE STRUT IS DIFFICULT ESPECIALLY WHERE IT JOINS THE BULKHEAD; THE AREA WHERE THE FAILURE OCCURRED. THE RPTR SAID THE MANUFACTURER HAS ALERTED HOME BUILDERS OF THIS KIT OF THE PROB WITH NEWER STRUTS.