What happened
The aircraft experienced a rapid loss of fuel quantity in the number one fuel tank while climbing to cruise altitude. The incident was traced to a maintenance error where the water separator access door had been replaced with a fabricated metal plate prior to the flight. During the climb, this unauthorized plate separated from its mounting point.
The investigation
Examination of the wreckage revealed that the separated metal plate inflicted significant damage to one of the number one fuel inspection plates. This structural compromise allowed fuel to dump overboard, leading to the rapid depletion of the tank's contents during the critical climb phase.
Findings
The primary factor was the installation of a non-standard fabricated metal plate in place of the proper water separator access door. The failure of this component in flight directly caused the damage to the fuel system inspection area.