Hallo leute hier mal eine erste stellungnahme zu den dataframe layouts und somit cockpit tür...hoffe euer english ist fit :-)
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Those who make this claim are confusing the Data Frame Layout (DFL) number with Aircraft Type. 757-3b is the proper Data Frame Layout required for N644AA as listed here in the NTSB pdf for N644AA.
http://www.ntsb.gov/doclib/foia/9_11/AAL77_fdr.pdf (Archiv-Version vom 10.10.2012)(bottom of page 2)
United 93 was also a 757-200 aircraft, but used 757-4 Data Frame Layout.
http://www.ntsb.gov/doclib/foia/9_11/UAL93FDR.pdf (Archiv-Version vom 03.05.2013)(also bottom of page 2)
DFL 757-3b (AA77, a 757-200) has the FLT DECK DOOR parameter which is why you see it listed under the parameters in the NTSB pdf and recorded in the data.
DFL 757-4 (UA93, a 757-200) does not list a FLT DECK DOOR parameter, which is why it is not listed in the NTSB pdf nor recorded.
Data Frame Layout (DFL) number does not correspond to specific aircraft type and are not interchangeable. The -2, -3b, -4 suffix are just revision numbers of the generic Data Frame Layout from Boeing. -3b is a specific revision for American Airlines and then was modified and custom made by American Airlines into 757-3b_1.txt specifically tailored for their 757-200 aircraft and needs specific to American Airlines. 757-4 is a revision number made for United Airlines specifically for their 757-200 Aircraft. United Airlines then custom made their own DFL from the generic Boeing 757-4 DFL into 757UALmap.xls, specifically tailor made for their 757-200 aircraft.
People who make the argument that the 757-2 DFL belongs to a 757-200 series aircraft are using a leap in logic just because they see a 2 after each number designation. They have absolutely nothing to do with each other. Using the same logic, DFL 757-4 should belong to a 757-400 aircraft... but such an aircraft does not exist. DFL 757-4 was made for United Airlines 757-200 series aircraft.
The Regs required only 18 parameter groups to be recorded on the FDR in 2001. This was a minimum requirement. Airliners record many more parameters specific to their needs.
American Airlines has 1100 parameters specified in their custom made data frame layout. Flight Deck Door is one of them.. See Attached below....
Read more here on common arguments with regard to the Flight Deck Door...
http://pilotsfor911truth.org/forum/index.p...&p=10779630