SEATTLE - Holes in airplanes drilled to hold rivets or bolts or any variety of fasteners are supposed to be round. But KING 5 has learned that some of the holes on that Southwest Airlines jet that blew a 5 foot long hole in its roof on April 1 out of Phoenix are not round, they are oval. The question, did they get that way because of of wear from the rivets themselves after tens of thousands of flights, or were they drilled incorrectly in the factory?
Boeing 737 fuselages are made in Wichita, Kansas in a facility that used to be owned by Boeing and is now owned by Spirit AeroSystems.
Boeing says airlines have inspected three quarters of the 190 older 737-300,400 and 500 series jets and has only found small subsurface cracks in five planes. The company says portions of those damaged panels have been removed and sent to Boeing for analysis. But there's no indication Boeing has found misshapen holes.
The NTSB said that the rupture that formed along a lower row of rivets in a lap joint along the upper or crown part of the fuselage of a Southwest Airlines 737 on April 1 was due to cracking of the fuselage skin along a rivet line. Concern over the shape of holes as it relates to this incident is something new. But hole size and shape is considered critical in aviation.