List of unrecovered and unusable flight recorders

Flight data recorders (FDRs) and cockpit voice recorders (CVRs) in commercial aircraft continuously record information and can provide key evidence in determining the causes of an aircraft loss. The greatest depth from which a flight recorder has been recovered is 16000 ft, for the CVR of South African Airways Flight 295. Most flight recorders are equipped with underwater locator beacons to assist searchers in recovering them from offshore crash sites, however these beacons run off a battery and eventually stop transmitting. For various reasons, a flight recorder cannot always be recovered, and many recorders that are recovered are too damaged to provide any data.