decodes the raw Flight Data Recorder (FDR commonly called "black box")
file for United Airlines Flight 93 (UAL93) included by the US National
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.
program allows you to selectively decode 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
Although the NTSB provided CSV files generated from the FDR file which
were also included on the CDROMs, I have created this program so that
parameters can be selectively included in the CSV files resulting in
with fewer columns and also to decode some information not included in
the NTSB CSV files.
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.
will need to download a copy of the FDR file ual93.dlu.
can download a copy from here.
You can also
get an ISO image of the entire CDROM that
I received in response to my FOIA request which
includes the FDR file from here.
Click on the button to choose
location of the FDR file.
Each subframe appears on a separate line in the output file. Subframes
are recorded in the FDR once per second.
Put a tick in the Include Incomplete Subframes check box if you want to
also include incomplete subframes in the output. Incomplete subframes
will most likely have some valid information and some invalid
information. The invalid information will likely consist of unusual
values. If you do choose to include the incomplete subframes, you will
probably want to mark "Incomplete Subframe" as one of the included
parameters in your output file (More on this below). This will let you
which lines may contain invalid information.
Put a tick in the Split Output File in to files containing no more than
30000 rows check box if you want the output file split up in to files
that can be more easily worked with in Microsoft Excel. The first 30000
rows will have the file name chosen in the CSV File To Be Generated
dialog box mentioned below. The second 30000 rows will have the same
file name but with the number 2 inserted before the last full stop in
the file name. The third 30000 rows will have the number 3 inserted in
the file name and so on. The last file name will have the remaining
rows. The first line of each output file will contain the parameter
a tick in the Maximum One Line Per Subframe check box if you want
only one line to be output for each subframe. This is the default
option. If the check box is cleared more than one line will be output
per subframe for the acceleration and some other parameters since there
for these parameters recorded in each subframe. If the check box is
only the first line will be output for each subframe.
The first time the program is
started; all the parameters are listed in
Excluded Parameters list box. Only the parameters listed in the
list box are included in the output file. I have grouped some of the
parameters that have similar names together so each entry in the
Included Parameters list box can create more than one column in the
To move parameters form the Excluded Parameters list box to the
list box, first select a parameter by clicking on it. You can select
than one parameter by holding down the SHIFT or CTRL keys while
the parameters. Then click on the
button to move the parameters you selected across. You can move all the
parameters across at once by using the
Similarly parameters can be moved back from the Included Parameters
list box to
the Excluded Parameters list box by using the
Once you have selected the parameters you want included, click on the
button to choose
where you want the output file to be saved and to generate the file.
All the program options will be disabled (greyed out) until the file
has been completely generated. Close the Output Progress dialog box if
you want to cancel generating the output file.
When you exit the program, the options you selected will be saved in
file UAL93FDRDecoder.config.xml in the same folder as the program and
reloaded next time you start the program.