decodes the uncompressed parts of the raw Flight Data Recorder (FDR
commonly called "black box")
file for American Airlines Flight 77 (AAL77) included by the US
Transport Safety Board (NTSB) on CDROMs provided in response to FOIA
(Freedom of Information Act) requests for information regarding the
events of September 11th 2001.
The program allows you to selectively
uncompressed parts of the FDR
generate a Comma Separated Value (CSV) file containing the selected
information. The first line of the CSV file contains the parameter
and it can be opened by various programs including Microsoft Excel and
Microsoft Access. Up to 4 subframes of uncompressed data is generated
in the file each time the FDR is started up which I believe happens
when the engines are started. After that, data is stored in a
compressed form which this program can not decode (which is
why I call it a partial decoder). Most of the data in the FDR file is
The method which the program uses to recognise uncompressed
data is not fool proof so it attempts to decode some of the compressed
data as if it were uncompressed. This shows up as lines with unusual
The subframes appear in the output in my best estimate of the order
they were recorded. For more details see the entries for the
Position, Bit Offset and Flight Stream Number parameters in Notes on Parameters for the AAL77 FDR
Although the NTSB provided CSV files generated from the FDR file which
were also included on the CDROMs, I have created this program to decode
information not included in
the NTSB CSV files.
can download output files generated by the program from here.
As I am providing this program free of charge, it is provided as is.
I take no responsibility for what the program does or doesn't do.
However, you can email
feedback to me (Warren Stutt).
You can download and install
using Microsoft Internet Explorer from here
A Change Log detailing the changes in different versions is available here
There is a help page
on using the program. You
can also press F1 when the program is running to bring up the same help
In the interests of transparency in showing that the program is really
generating its output from the raw FDR file, you can download the C# source code
used Microsoft Visual C# 2005 Express Edition to create it. You can
look at the .cs
source files using any text editor, and you can download the
Visual C# 2008 Express Edition from Microsoft
it. Alternatively, you may be able to get a DVD with the Visual Studio
Express Editions from your local Microsoft sales office. I have not
actually checked that it does compile with the 2008 Edition.
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