 The federal government on Tuesday will order emergency inspections on 175 Boeing 737 airliners, and is rethinking its approach to plane inspections after a Southwest Airlines jet tore open in mid-flight Friday night, ABC News has learned. Fatigue Cracks Found in Three Other Southwest Jets 
 
 Southwest said today that it has inspected some 90 percent of its 737-300s, which were removed from service after the weekend. So far, inspections have uncovered fatigue cracks in three planes, the airline said. 64 other planes have been inspected and returned to service, with a dozen other planes still requiring inspection. National Transportation Safety Board investigators found additional cracks on the same seam in the skin where it ripped open, NTSB board member Robert Sumwalt said. "Based on this incident and the additional findings, we expect further action from Boeing and the FAA for operators of the 737-300 fleet worldwide." A flight attendant was injured, but none of the 118 passengers was hurt. "It indicates that something is going on in that joint that should not be going on," Sumwalt said.
– The Federal Aviation Administration has ordered emergency inspections of 80 older Boeing 737s similar to the Southwest plane that suddenly cracked open last week during a flight. The order covers aircraft built with a specific process in the '80s and '90s and those that have more than 30,000 flight cycles, ABC News reports. Some 78 of the jets in question belong to Southwest Airlines—which has carried out its own inspections—and two are being used by Alaska Airlines. Inspectors must use an electro-magnetic process that detects cracks invisible to the naked eye. Neither the Federal Aviation Administration nor Boeing currently requires checks to be carried out on the section of aircraft that cracked open. The incident "could change the conversation regarding the risk of aging aircraft," and lead to tougher, more expensive inspections, the president of the Flight Safety Foundation tells USA Today.