Boeing, the FAA and the National Transportation Safety Board (NTSB) are investigating whether an incident involving an American Airlines Boeing 757 on October 26 is related to cracks found in the fuselage of a United Airlines Boeing 757 last month, reports The Wall Street Journal. In Tuesday's incident, which happened about half an hour into the American 757's flight from Miami to Boston, a hole about two feet long and a foot wide opened above the jet's front left cabin door and its cabin depressurized. The crew and 154 passengers on board donned oxygen masks and the aircraft descended to a lower altitude, then returned safely to Miami. The American 757 has been grounded for repairs and American has shipped the aircraft's flight data recorder and cockpit voice recorder to the NTSB's laboratory in Washington D.C. for analysis. The NTSB will also examine the ruptured portion of the fuselage.
Both the American 757 and the United 757 in which fuselage cracks were found in September had operated between 20,000 and 25,000 flights and aren't considered among the category of ageing aircraft which are prone to metal fatigue. The FAA requires older aircraft to undergo heightened scrutiny and more frequent structural inspections. According to The Wall Street Journal, Boeing is already working on a service bulletin (a safety-related advisory communication sent to all operators of an aircraft type) advising stepped-up inspections of certain areas of older 757s. Officials told the newspaper the American 757 incident bears resemblances to a July 2009 incident in which a Southwest Airlines Boeing 737 made an emergency landing at Charleston, West Virginia after developing a one-foot hole in the top of its fuselage just in front of its rear pressure bulkhead while the aircraft was at cruise altitude. In that incident, the oxygen masks deployed and the 737 was able to divert safely without any injuries to passengers or crew.