The New York Times has assembled and posted more than two hours of military, air traffic, and airline radio communications—some of it never before heard in public—from the morning of September 11, 2001. It is depressing and fascinating.
Astonishingly, a complete archive of the available audio documenting the attacks from the perspective of air traffic controllers and other people responsible for tracking the four doomed flights has never been assembled. Investigators working for the 9/11 Commission labored to pull together all the recordings they could find, but the draft "audio monograph" of 114 recordings they culled in 2004 came too late—the Commission was disbanded before a pre-release legal review could be completed. While many of the recordings were played at commission hearings, the full document remained secret.
Until last year, when a former 9/11 Commission investigator named Miles Kara recovered the files from the National Archives, and, in concert with students at Rutgers Law School, finished cataloging and transcribing them. The transcripts will be published by the Rutgers Law Review, and the audio is being posted by the Times. It's an amazing trove, and it boggles the mind that not even the commission tasked with generating a complete accounting of that day never thought to pore over every moment of audio.
There are two notable, and fascinating omissions: Thirty minutes of audio from the cockpit of Flight 93, caught when someone keyed one of the pilots' microphones, and a "high-level conference call" joined by Dick Cheney, Donald Rumsfeld, and others.
The audio is endlessly perusable. When Betty Ong, a flight attendant on American Airlines flight 11—which hit the North Tower of the World Trade Center—called her airline's operations center to report the hijacking, she reported that no one could get into the cockpit or if the pilots were safe.