PHOENIX – Federal records show cracks were found and repaired a year ago in the frame of the Southwest Airlines Boeing 737-300 that made an emergency landing at an Arizona military base after a hole was torn from the passenger cabin.
No one was seriously injured Friday as the aircraft carrying 118 people rapidly lost cabin pressure and made a harrowing but controlled descent from 34,500 feet, landing safely near Yuma, Ariz., 150 miles southwest of Phoenix.
But passengers recalled tense minutes after a hole ruptured overhead with a blast and they fumbled frantically for oxygen masks as the plane descended.
Federal investigators arrived in Yuma Saturday and said they were cutting a piece from the fuselage of the stricken plane to determine how the fuselage rupture occurred.
Southwest grounded 80 similar planes to carry out inspections.
An Associated Press review of Federal Aviation Administration records of maintenance problems for the 15-year-old plane showed that in March 2010 at least eight instances were found of cracking in the aircraft frame, which is part of the fuselage. The records showed that those cracks were repaired.
It's not uncommon for fuselage cracks to be found during inspections of planes that age, especially during scheduled heavy maintenance checks in which they are taken apart so that inspectors can see into areas not normally visible.
The National Transportation Safety Board worked to determine what caused part of the fuselage to rupture.
NTSB member Robert Sumwalt said investigators will study the cut-out fuselage piece for fracture patterns and examine the plane's black box and flight recorders.
Southwest officials said the Arizona plane had undergone all inspections required by the FAA. They said the plane was given a routine inspection Tuesday and underwent its last so-called heavy check, a more costly and extensive overhaul, in March 2010.