National Transportation Safety Board Case Study

National Transportation Safety Board - Case Study Example The investigation into the accident by the NTSB revealed that the probable cause of the accident was the asymmetrical stall and the aircraft’s ensuing roll due to the uncommanded retraction of the lift wing outboard that led to the edge slats and the loss of the slat disagreement and stall warning indication systems (Aviation Safety Network, 2012). This occurrence resulted from maintenance-induced damage that led to the separation of the pylon assembly procedures and the number one engine, which eventually led to the pylon structure’s failure (Vatz, 2003). This accident was mainly a result of structural and mechanical factors. Investigations by the NTSB revealed that when the engine separated because of the asymmetrical stall and the aircraft’s ensuing roll, it disabled the control panel of the Captain. The Captain’s control panel contained both systems of slat disagreement (National Transportation Safety Board, 1979). The separation of the pylon assembly procedures and the number one engine, which ultimately resulted in the failure of the pylon structure, are all structural and mechanical aspects of aircraft. The severed hydraulic lines allowed the slats on the aircraft’s left wing to retract gradually and the stall speed on the aircraft’s left wing rose significantly (Vatz, 2003). When it slowed through 164 knots, left-wing aerodynamically stalled because of its clean configuration. This happened while the right wing continued to generate lift with its slats still in the position of takeoff. Since one wing was stalling and the other was producing lift, the aircraft ultimately rolled past a 90 degrees bank and crashed to the ground (Kilroy, 2012). While structural and mechanical factors were the main cause of the accident, investigations revealed that there were factors that contributed to the accident of American Airlines Flight 191 (Aviation Safety Network, 2012). Report by NTSB reveals that the vulnerability of the pylon attaches points design to maintenance damage contributed to the accident.  Ã‚