Newsgroups: *rec.music.classical.guitar* From: *William D Clinger The FDR recorder in all educated circles is accepted as fact! FDR's > do not lie! It has been analyzed by some of Americas best, and > brightest minds, and hundreds if not thousands of pilots , crash > investigators, and aviation experts have signed on to validate the > data. For Christ sakes Richard the animation and data is from the > NTSB itself. It ain't that simple. The NTSB animation is not primary evidence. It is a tool for visualizing what happened. To the extent that the animation was derived from the FDR data, it is redundant with FDR data. To the extent that the NTSB animation extends the FDR data, it represents someone's interpretation (theory) of what happened, presumably based on additional evidence not contained within the FDR data. Furthermore, some of the FDR data (certainly position and time, possibly altitude) require calibration adjustments to resolve systematic discrepancies between FDR and radar data. A certain amount of subjective human judgement goes into that. No one outside the government has physical access to the FDR itself [1]. The FDR data are available to the public only in the form of computer files [2]. There are actually two distinct computer files, an FDR file that requires special software to decode, and a more convenient summary called a CSV file. The CSV file should have been derivative of the FDR file, but the CSV file has been reported to contain one extra data point at its end [3,4]. If true, that means the government once had access to an FDR file that is more complete than the one that has been made public. Whether the government still has that file and how much more data it contained are unknown. At least three investigators have reported that the last data point contained within the FDR files puts the plane on the order of a mile away from the Pentagon, several seconds before impact [3,4]. The position, time, and altitude for that last data point depend on exactly how the data were calibrated, which is slightly subjective. It takes time to transfer digital data from fast volatile buffer memory to nonvolatile memory, so we would expect to lose the last few data points before a crash. The particular model of flight data recorder that was used on Flight 77 wasn't supposed to lose more than a second or so of data, but maybe it did. It was a bad crash. There are mysteries here. It ain't simple, and people who want all mysteries to be resolved in the final chapter are going to be disappointed. Will [1] http://flight77.info/docs/AAL77_fdr.pdf [2] http://www.aa77fdr.com/ [3] http://911files.info/rades/911files_workbooks/NTSB_RADES%20Comparative%20Analysis.pdf [4] http://aal77.com/ntsb/Final%20Analysis%20of%20NTSB%20Fight%20Data%20Recorder%20Freedom%20of%20Inform.pdf