Super Galaxy McDonnell Douglas DC-10/KC-10 McDonnell Douglas MD-11 Accidents and incidents In 1973, a CF6-6 fan assembly disintegrated, resulting in the loss of cabin pressurization of National Airlines Flight 27 over New Mexico, United States. In 1979 a CF6-6 engine detached from the left wing of American Airlines Flight 191, severing hydraulic lines and causing the aircraft to crash. In 1989, a CF6-6 fan disk separated from the engine and damaged all three hydraulic systems. The flight, United Airlines Flight 232, continued with no hydraulic power until it crash-landed at the airport in Sioux City, Iowa. In 2000, the National Transportation Safety Board (NTSB) warned that the high-pressure compressor could crack. Following a series of high-pressure turbine failures on 6 September 1997, 7 June 2000 and 8 December 2002, and resulting in 767s being written off on 22 September 2000, on 2 June 2006, and on 28 October 2016, the Federal Aviation Administration issued an airworthiness directive mandating inspections for over 600 engines and the NTSB believed that this number should be increased to include all -80 series engines with more than 3000 cycles since new or since last inspection. In May 2010, The NTSB warned that the low-pressure turbine rotor disks could fail. Four uncontained failures of CF6-45/50 engines in the preceding two years prompted it to issue an "urgent" recommendation to increase inspections of the engines on U.S. aircraft : none of the four incidents of rotor disk imbalance and subsequent failure resulted in an accident, but parts of the engine did penetrate the engine housing in each case. Specifications See also References External links High-bypass turbofan engines CF6 1970s turbofan engines