Aal77 Fdr Decoder Program, Decodes almost 4 more seconds Options

[wstutt]

I have created a new program to decode AAL77's raw FDR file.

I am making it available for download along with it's source code and some output files from the program.

You can read more about it here

It decodes almost 4 more seconds of data than what appears at the end of the NTSB CSV file.

I welcome suggestions for any more parameters you would like decoded or any other features you would like added.

I will also be discussing this on the J.R.E.F. "AA77 FDR Data, Explained" thread as well as here.

Warren.

mod edit: Although Pilots For 9/11 Truth do not have any reason to believe the above program is offered for any nefarious purpose, we felt the responsibility to add this disclaimer. Pilots For 9/11 Truth do not vouch for nor is responsible for any of the data provided above by Warren. Nor can we guarantee his program is free of malicious code. Download at your own risk.

This post has been edited by rob balsamo: Oct 22 2009, 05:38 PM

[JFK]

Warren, is it possible for you to add a few more parameters to your decoder program ?

I am looking for Uid's :

CODE

L_ACT_FQ
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
11          4           256         1           12    
    
R_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
12          4           256         1           12  

C_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
13          4           256         1           12          

S_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
14          4           256         1           12

From 757-3b_1.txt

Thanks in advance.

Edit to add :

I have taken the last 4 words in column 256 of the binary file and done some manual conversions...
Do these sound correct ?

CODE

110010010000 = 3216        Center

000000000000 = 0        Surge

110100011110 = 3358        Left

110111001010 = 3528        Right

For a total of 10102 Lbs ( ~1496.6 gallons ) of total fuel onboard at the last moment of the FDR data.

Or am I totally wrong in my method ?

Another edit to add - Or do I multiply the lbs. by 39.99 first like this :

CODE

110010010000 = ( 3216*39.99 )    = 128607.84 lbs.     or ~19053     gallons     Center

000000000000 = ( 0*39.99 )        = 0 lbs.            or ~0         gallons        Surge

110100011110 = ( 3358*39.99 )    = 134286.42 lbs.    or ~19894     gallons        Left

110111001010 = ( 3528*39.99 )    = 141084.72 lbs.    or ~20901     gallons        Right

Assuming 6.75 lbs = 1 gallon.

?
( actually those last numbers seem high for the explosion witnessed... 3 tri-axle fuel transports full. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/blink.gif)

Granted that this is likely gasoline, but still... http://www.youtube.com/watch?v=TVHSaA30WBs )

[wstutt]

Warren, is it possible for you to add a few more parameters to your decoder program ?

I am looking for Uid's :

CODE

L_ACT_FQ
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
11          4           256         1           12    
    
R_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
12          4           256         1           12  

C_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
13          4           256         1           12          

S_ACTUAL
Frame(s)    Subframe(s) Word        Start Bit   End Bit    
14          4           256         1           12

From 757-3b_1.txt

Thanks in advance.

Edit to add :

I have taken the last 4 words in column 256 of the binary file and done some manual conversions...
Do these sound correct ?

CODE

110010010000 = 3216        Center

000000000000 = 0        Surge

110100011110 = 3358        Left

110111001010 = 3528        Right

For a total of 10102 Lbs ( ~1496.6 gallons ) of total fuel onboard at the last moment of the FDR data.

Or am I totally wrong in my method ?

Another edit to add - Or do I multiply the lbs. by 39.99 first like this :

CODE

110010010000 = ( 3216*39.99 )    = 128607.84 lbs.     or ~19053     gallons     Center

000000000000 = ( 0*39.99 )        = 0 lbs.            or ~0         gallons        Surge

110100011110 = ( 3358*39.99 )    = 134286.42 lbs.    or ~19894     gallons        Left

110111001010 = ( 3528*39.99 )    = 141084.72 lbs.    or ~20901     gallons        Right

Assuming 6.75 lbs = 1 gallon.

?
( actually those last numbers seem high for the explosion witnessed... 3 tri-axle fuel transports full. (IMG:http://pilotsfor911truth.org/forum/style_emoticons/default/blink.gif)

Granted that this is likely gasoline, but still... http://www.youtube.com/watch?v=TVHSaA30WBs )

Hi JFK,

Sorry it has taken me so long to reply.

You do need to multiply be 39.99 to get values in lbs. as in your last edit.

These values are not recorded in every frame (Frame(s) is not ALL) which means they are only recorded in 1 frame out of each 16 frames in a superframe. They are also not recorded in every subframe of that frame (Subframe(s) is not 1234) which means they are only recorded in 1 subframe out of the 4 subframes in the frame. So overall, each of these values is only recorded in 1 out of every 16 * 4 = 64 subframes.

To find which subframes contain the values, you first need to identify the superframe cycle numbers. These occur in bits 9 to 12 of word 256 of subframe 3. Subframe 3 has a value of 10 for bits 11 and 12 of word 1 (the leftmost 2 bits on each line in the file). For each of these lines the superframe cycle number is calculated by adding 1 to the 4 bit unsigned integer formed from bits 9 to 12 of word 256 i.e. the leftmost 4 bits of the last word on those lines. Subframe 3 occurs every 4th line and you should find the superframe cycle numbers count in binary from 0000 to 1111 then back to 0000 again. The last complete line in the file, line 151354 is subframe 3 with a superframe cycle number of 0011 binary + 1 = 4.

All the Frame(s) numbers in 757-3b_1.TXT need to have 1 added to them to produce the correct superframe cycle numbers as used by D226A101-3G.pdf. So if we take L_ACT_FQ as an example we are looking for a superframe cycle number of 11 + 1 = 12. The last line in the file where this occurs is line 151322. The next line in the file after Subframe 3 is Subframe 4 within the same frame and it is this line which contains the fuel quantity raw value in word 256, in this example that would be the last word in line 151323 which is 100000000000 in binary. That then needs to be multiplied by 39.99 as you did above to get lbs. If you move 4 lines down the file to line 151327, the last word in that line will be the raw value for superframe cycle number 13 or R_ACTUAL. If you again move down 4 lines to line 151331, the last word in that line will be the raw value for superframe cycle number 14 or C_ACTUAL. If you yet again move down 4 lines to line 151335, the last word in that line will be the raw value for superframe cycle number 15 or S_ACTUAL. All these last set of 4 fuel quantities have a raw value of 100000000000 in binary or 81899.52 lbs.

When I decoded the fuel quantities, the quantities for each tank cycled between 4 different values, which obviously shouldn't happen, so I have left them out of the decoder program for now.

Warren.