As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A ROUTINE POST FLIGHT INSPECTION, TWO RIVETS ON THE MAIN CABIN ENTRY DOOR WERE NOTED MISSING ALONG THE LOWER AFT CORNER. UPON FURTHER INVESTIGATION, A SUBSTANTIAL CRACK WAS FOUND ON THE MAIN ENTRY DOOR FRAME CHANNEL. THIS CHANNEL SUPPORTS THE HINGE FOR THE MAIN CABIN DOOR. IT IS SUSPECTED THAT A WEAK DOOR DAMPER ASSEMBLY WAS PLACING UNDUE STRESS ON THE DOOR HINGE AND STRUCTURE AS IT WOULD SUDDENLY CATCH AND SLOW THE OPENING OF THE DOOR HALF WAY DOWN