Flight Data Recorder

A flight data recorder, colloquially called a black box (although this term, within the context of aircraft, can refer to other things; see Flight recorder), also called a "Digital Expandable Flight Data Acquisition and Recording System" (DEFDARS) is a device used to record diagnostic information for aircraft so that this can be read after accidents. This is sometimes done after consolidation of data by a separate device alternatively called a "flight data acquisition unit", "flight data interface unit", or "flight data acquisition card".

There are complaints of the data format varying according according to manufacturers and users (the latter group apparently having the tendency to frequently make undocumented modifications). However, there is a general standard format, in which the data is divided into 4-second "frames", those into 1-second "subframes", and those into 12-bit "words" that hold different data parameters (sometimes across multiple frames each). Sources differ on whether or not information on the layout of these parameters is stored in the data recorder itself or only in external documentation.

Flight data recorder files seem to be stored with the conventional extension .fdr. Judging from what is available online, it is standard practice to convert the "raw" files to CSV before analysis.

Specifications

 * The webpage where the standard document "ARINC Characteristic 717-10, Flight Data Acquisition and Recording System" can be purchased for 262 USD
 * A United States government document apparently summarizing the previous specification

Links

 * A good overview of the subject written by the French government (text is in Engligh)
 * ICAO Annex 6, part 1, which contains several sections on flight data recorders, including lists of mandatory parameters
 * Examples and a "decoder" program
 * A United States government "handbook" for reading data from FDRs