Small transport pilot reported the aircraft made a sharp uncommanded turn off the taxiway; resulting...

Attributes
ACN	1619666
Time
Date	201902
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Small Transport Low Wing 2 Turboprop Eng
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Nosewheel Steering
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 18000 Flight Crew Type 75
Events
Anomaly	Aircraft Equipment Problem Less Severe Ground Event / Encounter Ground Strike - Aircraft Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Taxiway

Narrative:

After landing; contacted ground and was given instructions. After taxiing for about 3000 feet I was getting ready to turn right into the FBO. The aircraft suddenly made a hard 90 degree left turn; exited the taxiway into the grass where the nose gear sheared off. The nose gear shearing off caused both props to strike the grass. After talking with the a&P who maintains the aircraft; he described the operation of the connection of rudder pedals to the nose gear. His best guess; without examination; is that the hollow tube may have been corroded and when retracting gear on takeoff the tube may have partially failed. Turning on the taxiways may have caused complete failure.

Original NASA ASRS Text

Title: Small transport pilot reported the aircraft made a sharp uncommanded turn off the taxiway; resulting in nose gear failure and prop strike.

Narrative: After landing; contacted Ground and was given instructions. After taxiing for about 3000 feet I was getting ready to turn right into the FBO. The aircraft suddenly made a hard 90 degree left turn; exited the taxiway into the grass where the nose gear sheared off. The nose gear shearing off caused both props to strike the grass. After talking with the A&P who maintains the aircraft; he described the operation of the connection of rudder pedals to the nose gear. His best guess; without examination; is that the hollow tube may have been corroded and when retracting gear on takeoff the tube may have partially failed. Turning on the taxiways may have caused complete failure.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.