No distress call was made. Investigators have ruled out engine failure as a possible cause of the crash. Before takeoff, pilot Denver Mills told controllers he planned to fly to Stillwater, Okla., and then on to Oklahoma City, the tape shows. Later, an air traffic controller in Denver radioed that he could not reach the plane. The tapes do not give any indications of problems.
Voices are often absent or unintelligible.
The FAA released the tapes Tuesday under Freedom of Information Act requests. It did not release a transcript. The National Transportation Safety Board will not complete its preliminary report on the crash for another few months, spokesman Paul Schlamm said. The final report is expected late this year or in early 2002. Investigators plan to return this week to the site of the crash.