Finn47;
Those sample rates are reasonable and for the circumstances referred to by the AAIB would be of course accurate but these sample rates would not necessarily apply to all DFDRs. Sample rates depend upon the software installed, the size of the data frame and the design of the LFL, or Logical Frame Layout. FOQA QAR's are typically far richer in both the number of parameters recorded and the sample rates achieved. The data is typically on the ARINC 429/717 data busses (plus a few others) and being digital can be picked off at any rate - the data sampled and the rates achieved are a matter of equipment installed, storage medium and programming. In some military MFOQA applications, (thinking specifically of the C-17), approximately 40,000 parameters may be available. On our 320's, just under 2000 parameters are available whereas typical DFDRs will capture around 600 parameters. As usual, cost drives that is captured by each type of recorder.