What May Have Happened

This part necessarily involves an element of informed speculation. In a manner that is entirely analogous to a criminal investigation, the Panel constructs feasible scenarios that are evaluated against evidence on the ground. For example, there is solid evidence that no interceptors were launched within the normal time-frame employed by NORAD and the FAA in the case of off-course aircraft. A scenario that explains this evidence, as well as other anomalies found to occur on September 11, is provided by Operation Pearl. In the context of an investigation that questions widely held beiefs, scenario construction is unavoidable.