T7 B3 Cvr Notes- Ntsb Fdr- 1 Pg Summary- Data Sources Fo Rua 93- Aa 77 Cvr-animation Playback Effort 312

Data Sources For UA93/AA77 CVR/Animation Playback Effort All modern FAR Part 121 passenger jets are required to carry... S a Flight Data Recorder (FDR) that records at least 25 hours of airplane data and... S a Cockpit Voice Recorder (CVR) that records at least 30 minutes of voice communications transmitted from or received in the airplane by radio, voice communications of flight crewmembers on the flight deck, voice communications of flight crewmembers on the flight deck using the airplane's interphone system, voice or audio signals identifying navigation or approach aids introduced into a headset or speaker, and voice communications of flight crewmembers using the passenger loudspeaker system, if there is such a system and if the fourth channel is available. FDRs were found in the wreckage of both UA93 and AA77, and full 25+ hour data sets were recovered. CVRs were found in the wreckage of UA93 and AA77. AA77's CVR was so damaged by thermal energy (fire) that its data were not recoverable. UA93's CVR was damaged but recoverable and a full 31 minute recording was transcribed. Neither CVRs nor FDRs were found for either of the WTC airplanes. FDR, RADAR, and ATC data were used to develop the UA93 animation. CVR data will be played back synchronously with the animation for the Commission. FDR, RADAR, and ATC data were used to develop the AA77 animation.