As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL, VALVE PRESSURIZATION SYSTEM WENT INTO EMERGENCY PRESSURIZATION. VALVE HAD BEEN REPLACED 2.7 HOURS EARLIER FOR SAME PROBLEM. REPLACED BOTH LEFT AND RIGHT VALVES PER BEECH. AIRCRAFT TOTAL TIME 652.2 HOURS. OTHER AIRCRAFT IN FLEET HAS TOTAL TIME OF 840.2 HOURS TO DATE WITH NO SIMILAR PROBLEMS.