Metallurgical Findings From The Examination of a Turbine Engine Diffuser Case Rupture

On October 10, 2011 at about 3:04, eastern daylight time, a Delta Air Lines Boeing 757-200, powered by two Pratt & Whitney PW2037(M) turbofan engines, experienced a No. 1 (left) engine failure during takeoff roll at Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia. A post-event inspection found that the left engine was ruptured across the M-flange, where the diffuser case, nozzle guide vane support, and high-pressure turbine case were bolted together. The engine hardware was sent to the NTSB Materials Laboratory for metallurgical examination. The findings of the examination and probable cause of the case rupture will be discussed.