Unfortunately, the crew of Japan Airlines Flight reach the crew. Then, a supervisor jumped in The Swiss Cheese Model 907 were receiving con昀氀icting messages from and intended to instruct Flight 907 to climb, ATC and TCAS. Ultimately, the crew decided to but they accidentally addressed Flight 957, The Swiss Cheese Model of accident causation follow ATC’s instruction to begin descending, another 昀氀ight number that wasn’t involved in was developed by renowned psychologist unknowingly putting the plane on a collision this scenario at all! James T. Reason in the late 1990s.2 It’s a course with another aircra昀琀 nearby. If it weren’t popular model that provides one way to for a last second maneuver from the crew of Taken together, the event demonstrates visualize and explain the occurrence of Flight 907, a collision would have occurred, that a series of overlapping errors were systematic process failures, like observed in the and hundreds of lives would have been lost. 1 identi昀椀ed as contributing factors for the near story of Flight 907. mid-air collision. Aside from the con昀氀icting What happened here? instructions, there was little to no guidance Picture a slice of Swiss cheese. It’s covered with given to the crew on what to do if they received holes of varying diameters located randomly. At the time of the event, TCAS was functioning two opposing messages from ATC and TCAS. Each slice serves as a barrier (or control properly on each aircra昀琀 and, according measure) blocking the path from a known to their 昀氀ight plans, the two planes were When addressing accountability in situations hazard to an exposure that leads to failure or supposed to pass each other with more than like this, the question of responsibility loss (the accident trajectory). The more slices 2,000 feet of vertical separation - nearly twice becomes pivotal. In the context of the Japan of cheese between the hazard and the receiver the height of the Empire State Building. Airlines Flight 907 near miss, legal action was (individual), the less likely an adverse event will taken against the air tra昀케c controller, who occur. But like a slice of Swiss cheese, barriers Subsequent investigations into the event was undergoing training at the time, and their used to protect individuals from hazards have revealed that air tra昀케c controllers had supervisor, both facing charges of professional inherent 昀氀aws and systemic weaknesses (holes intended to instruct Flight 958 to descend negligence. Following an extensive trial in the cheese slices). System failure occurs but gave that instruction to Flight 907 by within the Tokyo District Court, the air tra昀케c when these holes momentarily align, allowing accident. A昀琀er detecting the error, ATC sent controller and supervisor were ultimately a hazard to pass through and reach a receiver, another message to Flight 907 to turn their deemed guilty and received sentences of 12 creating an exposure. plane to the right, but the message didn’t and 18 months of imprisonment, respectively.1 © CORITY SOFTWARE INC. 6