As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAIN TIRE WENT FLAT ON TAXI OUT. REMOVED LEFT TIRE AND WHEEL ASSY. FOUND 5 INCHES OF INBOARD BEAD SUPPORT AREA OF WHEEL MISSING. SUSPECTED CAUSE OF DEFECT DUE TO AGE AND IMPROPER PROCEDURE OF DISMOUNTING TIRE, I.E., USING SCREWDRIVERS TO BREAK TIRE BEAD.