Southwest Mishap Investigation Focuses On Rivets

SACRAMENTO (CBS13) -- A federal investigation into the Southwest Airlines flight forced to make an emergency landing after part of the fuselage ripped open earlier this month is closely examining the rivets that kept the skin of the aircraft fastened together.

The National Transportation Safety Board released a photo showing the part of the fuselage that failed during Flight 812 from Phoenix to Sacramento on April 1, displaying a 9-inch by 59-inch rupture in the aluminum material.

The cabin rapidly depressurized and the flight made an emergency landing at an Arizona military base. No serious injuries were reported among the 118 occupants.

The NTSB says a number of tests still remain before they can issue any conclusions, but investigators have discovered that 42 of the 58 rivet holes connecting the two sections of the aircraft's skin at the fuselage's crown showed signs of fatigue fractures.

Inspections also revealed that there were small gaps between several of the rivets and rivet holes. Some of the rivets were found to be slightly offset to each other.

Boeing has issued service advisories of some 737 aircraft to inspect the fasteners in the area that failed on Flight 812.