The cockpit voice recorder from Flight UA93
by Elias Davidsson
According to official sources, the only retrieved and readable Cockpit Voice Recorder (CVR)( from 9/11 belonged to flight UA93 which allegedly crashed on a field in Pennsylvania. The FBI controlled the analysis of that CVR and initially opposed to have even family members listen to it.1 Questions remain about the authenticity of this CVR: Transcripts of CVRs from other aircraft crashes around the world, that are publicly accessible on the internet, mention numerous engine and other ambient sounds from the cockpit in addition to conversation.2 The transcript of Flight UA93’s CVR does not mention any such sounds3 and particularly no crash sound at the end, as would be expected,4 suggesting that the transcript does not faithfully reflect what is heard in the recording. German author Gerhard Wisnewski made a pertinent observation that the released transcript differed significantly from authentic CVR transcripts by failing to mention the aircraft’s ID, the name of the person and the agency who issued the transcript and the date the transcript was issued.5 The released transcript cannot, therefore, be attributed to any transcriber. Furthermore serious discrepancies have been revealed between what family members heard when the CVR was first played to them by the FBI on 18 April 20026 and what the 9/11 Commission reported to have heard from the CVR recording at a later date. These discrepancies suggest that the CVR recording has either been manipulated7, that two versions had been made from one CVR or that the released documents had been fabricated.
1 Reuters News Service, ‘FBI refuses to release cockpit tape from hijacked flight’, Houston Chronicle, 20 December 2001. Available at http://www.chron.com/disp/story.mpl/special/terror/front/1181993.html
2 See EgyptAir 990 CVR Transcript: http://www.ntsb.gov/Events/EA990/docket/Ex_12A.pdf; SwissAir Flight 111 CVR Transcript: http://aviation-safety.net/inv….._sr111.php; TWA Flight 800 CVR Transcript: http://aviation-safety.net/inv….._tw800.php
4 Released CVR recordings from aircraft crashes are available at http://www.airdisaster.com/cvr/cvrwav.shtml