The purpose of this short article is to provide links to the CVR and FDR files for flight UA 93.
Flight Data Recorder (FDR)
Here is a link to the FDR readout as provided to the Commission, archived by NARA, and posted by History Commons on Scribd. The readout shows that UA93 started erratic maneuvers shortly after 9:58 and started climbing at 9:59, ultimately to 10,000 feet altitude by 10:02. The speed readout showed up and down variations beginning about 10:01.
At 10:02 the aircraft began its plunge to ground, accelerating from 300 knots to 500 knots at impact. NTSB determined the impact time to be 10:03:11. The Commission used NSTB-computed impact times for all four hijacked aircraft.
Cockpit Voice Recorder (CVR)
Here is a link to a time-stamped transcript in English and Arabic as provided to the Commission Staff by the FBI, archived by NARA, and posted by History Commons on Scribd.
The CVR correlates to the FDR in every respect. The words “Yes, put it in and pull it down” were spoken shortly after 10:01, followed by the words “down, down” at 10:02:18, and “pull it down” at 10:02:23. The recording ended at 10:03:10.9.
Transponder back on
During the plunge to ground the transponder became activated. That fact was noticed by Cleveland ATC and reported in near real time to Herndon Center. At 14:02:45 a reinforced (radar and beacon) return (84th RADES data point, corrected) showed the plane to be at 7800 feet. At 14:02:57 a beacon (transponder) only return (84th RADES data point, corrected) showed the plane to be at 6100 feet, an instantaneous descent rate of 8500 feet per minute, a rate that was increasing as the plane accelerated.
Convergence of evidence
The primary source evidence is conclusive as to the fate of UA 93. The hijackers flew it into the ground while under attack by the passengers and remaining crew. It impacted at 10:03:11.
Any other explanation is speculative and without merit.