8:23 a.m.-8:25 a.m. September 11, 2001: American Airlines Operations Center Tries to Contact Flight 11, But Gets No Response

At 8:23 a.m., a flight dispatcher at the American Airlines operations center in Fort Worth, Texas sends an ACARS text message to Flight 11. ACARS, meaning Aircraft Communications and Reporting System, is an e-mail system enabling company personnel on the ground to rapidly communicate with those in the cockpit of an in-flight aircraft. The message says, “Good morning… ATC [air traffic control] looking for you on [radio frequency] 135.32.” No response is received from Flight 11. Two minutes later, an American Airlines air traffic control specialist at the operations center sends another ACARS message to Flight 11. This says, “Plz contact Boston Center ASAP… They have lost radio contact and your transponder signal.” Again, no response is received from the plane. Subsequent ACARS messages also receive no reply. [9/11 Commission, 8/26/2004, pp. 9-10 ]