NTSB Affirms Dubious Explanation For Pentagon "Black Box" Data File Time Stamp Discrepancy
NTSB Answer To Request For Correction Appeal
Within a Request for Correction appeal response, the NTSB affirms its prior position regarding a Flight Data Recorder (FDR) download file attributed to the FDR recovered from the crash scene of American Airlines flight 77, containing a creation time-stamp preceding the discovery of the said FDR by over four hours.
NTSB General Counsel Gary L. Halbert:
"Finally, you state that "the 'FDR' file 'American 77' contains a 'Modified' time and date stamp of 'Thursday, September 13, 2001, 11:45:38 PM,' indicating that edits and modifications to this file were completed 4 hours and 15 minutes before the FDR reportedly belonging to American Airlines flight 77 was actually recovered," and that, "[t]herefore, the use by the NTSB of information obtained from the 'FDR' file' American 77' ... is obviously in error." This also, as previously indicated, is not an error."
However, the "FDR" file "American 77" should contain a "modified" or "accessed" time that follows the FDR recovery date and time of Friday, September 14, 2001 at 4am. Instead, the date and time reflected within the file properties for "FDR" file "American 77" is "Thursday, September 13, 2001, 11:45:38 PM".
"Searchers on Friday found the flight data and cockpit voice recorders from the hijacked plane that flew into the Pentagon and exploded, Department of Defense officials said. The two "black boxes," crucial to uncovering details about the doomed flight's last moments, were recovered at about 4 a.m., said Army Lt. Col. George Rhynedance, a Pentagon spokesman."
Also contained within the NTSB notice is an apparent concession by the NTSB that they were not provided with information vital to performing data downloads from the FDRs contained by the aircraft involved in the terrorist attacks of September 11, 2001 - downloads that presumably were of immediate interest to authorities.
NTSB General Counsel Gary L. Halbert:
"You repeat that you have asserted that "DCA01MA064 and DCA01MA065 do not list FDR part and serial numbers required to facilitate the FDR the [sic] data readouts contained within each report," and state that '''FDR Part number and Serial Number' [are] required 'to facilitate data readout'." You argue that the "absence of [this information] demonstrates that information required to generate FDR downloads was not made available to the NTSB," and that you have "therefore determined that authentic FDR data downloads were not performed." As you were previously informed, however, in response to your public inquiry to the NTSB's Web Mailbox, FDR data read-out can be accomplished without part and serial numbers."
Within June 11 and June 16, 2008 NTSB Public Inquiry Web Mailbox replies are described the more complicated alternatives to using FDR part and serial number information contained within aircraft records that were apparently withheld from the NTSB by the FBI, the lead investigative agency of the September 11 attacks.
"Each recorder does have a unique serial number that is assigned by the manufacturer at the time it is made. In addition to the unique serial number there is a part number that associates the unit with a particular family of recorders. Every recorder has a dataplate affixed to the outside of the unit stating the serial number, part number, date of manufacturer, TSO certification, power requirements and weight. The part number will stay the same even though subtle changes may be made during the manufacturing lifecycle of the recorder. The manufacturer may change some components within the unit as long as the functionality and interchangeability of the unit remain the same. This is where the serial number becomes important. If a recorder with the same part number comes in we need to know what parts were used to make it and that is tracked by individual serial numbers of the recorder. The Safety Board will include the manufacturer, the part number and the serial number of the recorder in its formal reports (if known)."
"We usually work around the part numbers and or serial numbers. Most recorders have internal parts that are also serialized and the recorder manufacturer can trace a particular internal sub-part back to a finished unit. So we are usually able to reverse generate a part number and serial number for a recorder (if needed)."
Presumably, if the recovered AA 77 and UA 93 FDR's did not possess the memory configurations indicated within FAA and airline aircraft records, a mismatch could become apparent to NTSB investigators.
Of all major U.S. airline crashes within the U.S. investigated and published by the National Transportation Safety Board during the past 20 years, the 9/11 'black boxes' are virtually the only ones without listed serial numbers.