The National Transportation Safety Board said in a report this week that a UPS cargo plane that crashed in Louisville, Ky., last year, killing 15, had a structural flaw that the manufacturer Boeing had previously concluded would not affect flight safety. The New York Times: The N.T.S.B. has said that cracks in the assembly holding the left-side engine in place may have contributed to the November crash, though it has not officially cited a cause. The part had fractured in similar fashion on at least four other occasions, on three different airplanes, according to the report, which cited a service letter that Boeing issued in 2011 regarding the apparent flaw. In the service letter, which manufacturers issue to flag safety concerns or other problems to aircraft owners, Boeing said that fractures "would not result in a safety of flight condition," N.T.S.B. investigators wrote. The plane that crashed was an MD-11F jet, made by McDonnell Douglas, a company that Boeing acquired in the 1990s. It was taking off from Louisville and bound for Hawaii on Nov. 4 when a fire ignited on its left engine shortly after takeoff. The plane crashed into several buildings, including a petroleum recycling facility, on the outskirts of the Louisville Muhammad Ali International Airport. The three crew members on board and 11 people on the ground were killed in the crash; a 12th person on the ground died of injuries sustained during the episode.Read more of this story at Slashdot.