Abstract: (Version 2: New supporting evidence is presented and footnoted.) The alleged flight performances of inexperienced terrorist pilots accused of operating complex flight control systems of four aircraft during the terrorist attacks of September 11, 2001, has surprised observers. Moreover, official information presented to demonstrate terrorist pilot control of the said aircraft has been either unverifiable or demonstrated to contain noteworthy anomalies. The flight paths of the September 11, 2001, attack aircraft bear characteristics common to the capabilities provided by precision automated flight control systems and related commercial aviation technology that emerged just prior to these attacks. The unreported use of augmented GPS-guided auto-pilot aircraft systems in order to perform the said aircraft attacks is hypothesized.