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Watchlist 2010

Data recorders

Added to Watchlist on August 16, 2010


Data critical to understanding how and why transportation accidents happen are frequently lost, damaged, or not required to be collected.


Following any accident, investigators have a long list of questions, starting with "what happened," and "why." A prime source for information is the onboard recorders—the voice data recorder (VDR) on a vessel, a locomotive's Locomotive event recorder (LER), or an aircraft's Flight data recorder/cockpit voice recorder (FDR/CVR). These devices contain valuable information such as engine and equipment settings, navigation details, voice recordings, and computer data that can help pinpoint what happened. Recorders, however, can be lost or damaged in accidents, or not even required by law to be on board.

In the marine industry, although a small number of Canadian passenger vessels have been voluntarily fitted with voyage data recorders, none of the ferries operating domestically—which carry tens of millions of passengers annually—are legally required to carry them.

Lost locomotive data in the rail industry has impeded investigation efforts in six fatal railway accidents in the last 18 years.Footnote 1 And although new crashworthy recorders are slowly being phased in as older locomotives reach the end of their service life, given the 20-30 year lifespan of locomotives, successful replacement of all recorders may be decades away.

Although the aviation industry has enjoyed the benefits of voice and data recordings for approximately 50 years, critical information has been lost by being overwritten or by a loss of power to the recorders.

Without a secure, retrievable information record, the search for hard evidence becomes more difficult. This can translate into longer investigations, which in turn can cause delays that place public safety at risk. With objective data, however, it is easier to pinpoint safety deficiencies which, when corrected, will make the system safer.



In the air mode, the TSB has made recommendationsFootnote 6 that the duration of all cockpit voice recordings be extended to two hours (from the currently mandated 30 minutes). Although there has been some industry movement toward this, a final regulatory change in Canada has yet to be made.


The TSB has previously emphasized the benefits of vessels carrying voyage data recordersFootnote 2 and, following the fatal 2006 sinking of a passenger ferry in British Columbia, the TSB recommended that all large passenger vesselsFootnote 3 be required to carry VDRs (or a simplified version).Footnote 4 To date, however, this has not happened.


The TSB has also emphasized the survivability of recorded data on trains, and made multiple calls for improved crashworthiness standards to better preserve data.Footnote 5 Older recorders, however, may remain in service for decades.