Allan Knox Profile: Allan Knox Events (2) 10:07 a.m. September 11, 2001: Air Traffic Control Suggests that No Distress Signal Indicating a Plane Has Crashed Was Noticed When Flight 93 Went Down 2001-09-11 9:53 a.m. September 11, 2001: Emergency Transmitter Goes Off, Indicating a Plane Crash in Michigan 2001-09-11