SMA PLT LOST CTL OF THE SAME ACFT 2 DAYS IN A ROW. ACFT VEERED TO THE R AFTER NOSEWHEEL TOUCHDOWN. ACFT DEPARTED THE RWY.

Narrative

ACFT WAS IN A NORMAL LNDG POS; WITH 4 PAX PLUS BAGGAGE ON 1 HR FLT IN SMOOTH; CLR CONDITIONS. ACFT WAS CLRED TO LAND; RWY 10L AT BOISE BY BOISE TWR. NORMAL FLARE WAS INITIATED AND AT NOSEWHEEL TOUCHDOWN ACFT RADICALLY AND ABRUPTLY VEERED TO THE R. FULL BRAKES WERE APPLIED AND ACFT DEPARTED RWY AND DID AN ALMOST 360 DEG TURN IN THE DIRT AND CAME TO REST FACING THE RWY. THE PLANE WAS STILL RUNNING AND I WAS ALERTED TO TAXI TO THE TERMINAL AND TOLD TO CALL THE TWR (FROM A LAND LINE PHONE). THERE WERE NO INJURIES; NO DAMAGE TO THE ACFT NOR ANY DAMAGE TO THE RWY ENVIRONMENT. CLOSE INSPECTION OF THE ACFT DID NOT REVEAL ANYTHING BROKEN OR ANY DIRECT CONNECTION; SUCH AS BLOWN TIRE; BROKEN CABLES; ETC. SPECULATION WAS THAT NOSE GEAR MAY HAVE BEEN COCKED TO THE R DUE TO PAX PUSHING ON R RUDDER AT TOUCHDOWN. I KNOW THAT I DID NOT HAVE R RUDDER TRIMMED IN; NOR DID I STEP ON R BRAKE AT TOUCHDOWN. PLANE WAS FLOWN BACK TO HOME BASE WITH 2 LNDGS WITHOUT INCIDENT. NEW BRAKE PADS AND TIRES WERE INSTALLED; BUT NO WORK WAS DONE ON NOSE STRUT. ALSO; PLANE WAS FLOWN IN BACK-COUNTRY AIRSTRIPS AND THE OLEO STRUT WAS KEPT HIGHLY INFLATED. SUPPLEMENTAL INFO FROM ACN 408428: THOROUGH INSPECTION AND TESTING OF NOSE STRUT ASSEMBLY REVEALED A POSSIBLE PROB WITH THE NOSE STRUT BUNGEE SYS; BUT WAS NOT TOTALLY CONCLUSIVE. ACFT WAS FLOWN BACK TO HOME BASE WITH A FERRY PERMIT AND MAINT WAS PERFORMED. AT TOUCHDOWN; NO BRAKES WERE BEING APPLIED; TRIM CTLS WERE IN NEUTRAL POS AND ROLLOUT WAS ON THE CTRLINE. PLT FEELS THAT NOSE GEAR (STRUT) WAS STRIKING OUT OF CTRLINE; COMBINED WITH EXCESS AIR PRESSURE IN STRUT; CAUSED SIT WHERE RUDDER INPUTS WERE USELESS ON THE GND.