Examination of a Fractured Beechcraft B200 King Air Cabin Door Hook Bolt

On September 9, 2024, a B200 King Air, experienced a pressurization loss climbing through FL233, causing oxygen masks to deploy and the flight to be diverted to the departure airport. Post incident inspection revealed that one of the cabin door hooks had failed leading to the door partially opening. The bolt was provided to the Textron Aviation M&P department, and a laboratory examination was performed with representatives of the NTSB, FAA, and SIA-Iceland in attendance. The laboratory examination of the failed bolt revealed evidence of corrosion and branching intergranular fracture. This presentation will provide an explanation of the examination methods and findings.