LOT Polish Airlines Flight 5055 accident's cause was similar to that of LOT Polish Airlines Flight 007's crash seven years earlier. After the disaster of Flight 007, the Polish investigatory commission established that its engine shaft disintegration was the result of metal fatigue; improper alloy preparation resulting in a defective mechanism which was less resistant to fatigue; and a faulty design of the engine shaft. Detection of these faults was possible only after complete disassembly of the engine and detailed analysis of all its elements, and as such was beyond the capabilities of aircraft maintenance personnel. These concerns were addressed by the Polish Government's Special
Virtual airline (hobby) and The Pentagon had used PC-based flight simulators for training. Despite the initial concerns of the involvement of virtual airlines in these terrorist activities, largely little has come from these claims to date and no changes have been noted as occurring in their operation as a result. Virtual airline (hobby) A virtual airline (VA) is a dedicated hobby organization that uses flight simulation to model the operations of an airline. Virtual airlines generally have a presence on the Internet, similar to a real airline. Many hundreds of virtual airlines of significance are currently active, with tens of thousands of participants