Timeline for How does a CVR / FDR determine when to stop recording?
Current License: CC BY-SA 3.0
9 events
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| Nov 21, 2018 at 23:05 | comment | added | Vikki | @JanHudec: I know of at least one case (a near-MAC in the 60s or 70s; I'll add a link when I get home and can look it up) where the flightcrew of one of the planes involved pulled the CVR's breaker a few minutes after the fact, which significantly aided the NTSB's investigation; OTOH, this was back when they only recorded 30 minutes (usually plus one or two more to be on the safe side), rather than 120, so preserving the recording would have been significantly more time-critical than it would nowadays. | |
| Apr 1, 2015 at 14:22 | history | edited | Jan Hudec | CC BY-SA 3.0 |
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| Apr 1, 2015 at 12:12 | comment | added | raptortech97 | @JanHudec oh, thanks! That makes sense. And the FDR will probably still have the data, which is something at least. | |
| Apr 1, 2015 at 12:03 | comment | added | Jan Hudec | @raptortech97: They don't. They should do it after landing. So if it's more than 2 hours, the recording won't be there anyway (it may be in the QAR though, they usually have more data). | |
| Apr 1, 2015 at 10:57 | comment | added | raptortech97 | What if there's a TCAS activation, so they stop the recorders, and then later in the flight they crash? | |
| Apr 1, 2015 at 9:56 | comment | added | RedGrittyBrick | Agreed. Maybe the businesses involved just don't voluntarily make improvements over what regulations require (set in the days of magnetic tape recording). I don't understand what significant obstacles there could be other than institutional inertia and maybe certification costs. | |
| Apr 1, 2015 at 9:44 | comment | added | Jan Hudec | @RedGrittyBrick: I wonder why the new types don't store longer recording. Quick calculation tells me the raw 4-channel sound would be around 1¼Gb/h which does not sound like that much (yes, it should probably not use the most integrated chips as resilience is more important, and it is probably stored in multiple copies but I would still expect a bit more to fit in the box). | |
| Apr 1, 2015 at 9:24 | comment | added | RedGrittyBrick | "the last two hours before the crash is most important" - Almost always, but probably not in the case of MH370. | |
| Apr 1, 2015 at 8:10 | history | answered | Jan Hudec | CC BY-SA 3.0 |