Template:8:14 a.m.-8:24 a.m. September 11, 2001: Air Traffic Controller

8:14 a.m.-8:24 a.m. September 11, 2001: Air Traffic Controller Repeatedly Tries to Contact Flight 11
After Flight 11 fails to respond to an instruction from air traffic control to climb to 35,000 feet, the controller handling it, Pete Zalewski, tries to regain contact with the aircraft. Over the following ten minutes, he makes numerous attempts but without success. (Zalewski says he makes 12 attempts; the 9/11 Commission says nine.) He tries reaching the pilot on the emergency frequency. Zalewski later recalls that initially, "“I was just thinking that it was, you know, maybe they—pilots weren’t paying attention, or there’s something wrong with the frequency.… And at first it was pretty much, you know, ‘American 11,’ you know, ‘are you paying attention? Are you listening?’ And there was still no response.”"

"“I went back to the previous sector to see if the pilot had accidentally flipped the switch back over on the—on the radio.”"

But as Zalewski is repeatedly unable to get any response from Flight 11, he recalls, “I even began to get more concerned.” However, Zalewski claims, it is not until he sees the plane’s transponder go off at around 8:21 that he suspects something is “seriously wrong,” and calls his supervisor for assistance. And it is not until about 8:25 that he realizes for sure that he is dealing with a hijacking. It is only then that Boston Center starts notifying its chain of command that Flight 11 has been hijacked