@oldoberon, 31 Mar 2015 at 09:37 --
There are a variety of recorder models and manufacturers.
The FDR in the AF 447 accident was a Honeywell 4700. The spec:
http://www51.honeywell.com/aero/comm...28SSFDR%29.pdf
"The SSFDR's crash survivable memory unit (CSMU) provides for complete data recovery when subjected to the crash conditions stipulated in ED-55 and ED-56a: Impact Shock 3400G, 6.5 milliseconds . . . "
The BEA final report on AF 447 states that "For the FDR, only the protected unit (CSMU or memory module) was present. The CVR was complete."
The EUROCAE and RTCA documents (e.g., ED-55) that have the detailed requirements are on pay-per-view sites.
A few popular press articles (not specs):
BBC NEWS | Special Reports | Flight recorders: clues to air crashes
AutoSpeed - Inside the Black Box