On August 3, 2026, my Tesla Model Y was traveling at approximately 50 mph with Tesla Full Self-Driving (FSD) engaged. At approximately 4:12:47 PM CDT, FSD became unavailable and then became available again. At 4:12:51.628 PM CDT, FSD was recorded as ACTIVE_FSD again. Approximately 2.36 seconds after FSD was re-engaged, at 4:12:53.987 PM CDT, the vehicle's steering began a sudden and rapid rightward movement. I did not turn the steering wheel or intentionally provide a rightward steering input that initiated this maneuver. The recorded steering angle increased rapidly from approximately +11.4° to +20.7°, +33.3°, +83.3°, +137.9°, +154.7°, and ultimately approximately +282° within about 1.6 seconds. Importantly, FSD was still recorded as ACTIVE_FSD when the steering movement began. FSD changed to UNAVAILABLE at approximately 4:12:54.364 PM CDT, about 0.38 seconds after the steering movement had already started. The steering continued to escalate after FSD became unavailable.The vehicle subsequently experienced severe lateral acceleration of approximately 0.96 g, and crash detection activated at approximately 4:12:55.710 PM CDT. The accelerator was recorded at 0% during the developing steering event and increased only after crash detection. Hard braking and ABS activation occurred afterward.I do not have Tesla Dashcam footage, but I have retained Tesla's vehicle telemetry export containing FSD state, steering, steering-torque, accelerator, braking, vehicle-speed, stability-co