Many, many weeks. Digital FDR's storage capacity is nearly limitless considering the nature of the data stored. Not only can months of info be stored, new aircraft have a quick download port so the data can be retrieved in seconds without crawling around the arse end of the aircraft. Most engine warranties and safety programs (FOQA) require the constant download of FDR info. So...what did you do? If it was really interesting take a look at your contract and make sure that FDR data is not allowed for enforcement action. From your aircraft experience you look like a mesaba guy. I know your contract administrator and she has first hand experience dealing with this sort of thing with another carrier.