As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE PRIMARY INSPECTION, FLAPPER VALVE TEST WAS PERFORMED IAW BEECH MODEL 90 MM. VALVE FAILED TEST AND WHEN REMOVED, IT WAS DISCOVERED THAT THE RUBBER DIAPHRAGM INSIDE THE VALVE HAD SEPARATED FROM ITS HINGE AND WAS CARRIED INTO THE BLEED AIR DISTRIBUTION SYSTEM. PART WAS REPLACED AND SYSTEM RETURNED TO NORMAL OPERATION. RECOMMEND VISUAL INSPECTION AT 600 HOURS RATHER THAN A FUNCTIONAL CHECK.