After arriving at FAA headquarters on September 12, Tony Ferrante, the manager of FAA investigations, spends several days working out the movements of the four hijacked planes. He is astonished at the precision with which they were flown towards their targets, later saying: “[I]t was almost as though it was choreographed.… It’s not as easy as it looks to do what they did at 500 miles an hour.” He concludes that either the hijackers were better pilots than originally thought, or they were aided by additional equipment such as radios to communicate among the four planes or handheld Global Positioning System (GPS) equipment. [Freni, 2003, pp. 74 and 76] 9/11 Commission investigators will in fact later speculate that the hijackers may have purchased GPS devices, “so they could determine the latitude and longitude of their intended targets.” According to a summary of a Commission interview, “Any autopilot changes made by the terrorist pilots to assist them in navigating to predetermined coordinates would simply have been to enter a specific location such as Newark or Reagan National” Airport. However, airline personnel will tell the 9/11 Commission investigators that “Entering changes to the autopilot is something that terrorist pilots probably would not have been trained or able to do.” Even a United Airlines senior pilot, who instructs on how to do this, says “he always has to pause before he makes such corrections to make sure to remember how to enter the change.” [9/11 Commission, 11/17/2003 ]