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Are there any correctives or countermeasures against the rare irony, that objects essential to a flight accident (eg recovered flight data recorder and cockpit voice recorders) are damaged or destroyed on a subsequent flight carrying them? The worst case is if this freight flight crashes.

Context: As in many other Air Crash Investigation episodes, Season 14 Episode 4 (available on Youtube) concerns Copa Airlines Flight 201. Due to a lack of facilities in Panama or Colombia, the recovered FDR and CVR and other parts (including the cockpit instruments) had to be transported to the NTSB's labs in Washington, DC, USA. I presume that for want of expediency, they were freighted by air?

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    $\begingroup$ This is a bit like asking "What happens if you win the lottery while being struck by lightning?" $\endgroup$ – Calphool Feb 25 '15 at 2:09
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    $\begingroup$ Plane crashes are very rare. The chance of critical investigation components being lost in a plane crash is very low. Also, even the black boxes aren't necessarily critical - investigations have been completed without them. $\endgroup$ – raptortech97 Feb 25 '15 at 2:14
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    $\begingroup$ Well, it's so extremely unlikely to happen, there's probably absolutely no contingency for it. We'll lose the ability to determine with certainty what happened on the first plane, and we'd revert to the type of investigation that happens on most VFR flights. $\endgroup$ – Calphool Feb 25 '15 at 2:15
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    $\begingroup$ Umm, if the black box can survive one crash, why would you think that it couldn't survive a second? They are built just for survivability.... $\endgroup$ – Lnafziger Feb 25 '15 at 2:21
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    $\begingroup$ @UnrecognizedFallingObject One recorded item is the time, and another (on aircraft where the information is available) is latitude and longitude. Especially if either recorder has the latter, it shouldn't be too hard to sort out which one is which. The real worst case would be if the plane carrying the investigation team crashes -- you can do an investigation without the FDR, but losing a lot of trained investigators and all they've learned but didn't write down yet would be far worse for the investigation. $\endgroup$ – cpast Feb 25 '15 at 4:08
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If the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) need to be transported by airfreight, to expedite extraction of the recorded data and analysis of the accident, the probability of the aircraft used to ferry the devices crashing is rather low, as aircraft accidents do not happen as frequently compared to the total of movements per day/week/month/year.

Nevertheless, in the event of the aircraft used to ferry the devices crashing, the FDR and CVR are built to survive crashes and impact, so the probability of the first pair of FDR and CVR being still usable for data extraction after a second crash is quite high.

Since the FDR and CVR record not only data but also timestamps along with the data, the distinction between the FDR/CVR from the first crash and the FDR/CVR from the second crash is not a problem. Upon data extraction, the investigating party would recognize which flight parameters belong to which flight. Additionally, if the FDR and CVR on both flights were identical models, the serial number of each device would help identification.

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  • $\begingroup$ If the FDR and CVR are so robust that they can survive (multiple) plane crashes, why isn't the whole plane made out of that stuff? $\endgroup$ – dotancohen Apr 15 '15 at 17:51
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    $\begingroup$ Cost! Weight! Maintenance! @dotancohen $\endgroup$ – SentryRaven Apr 15 '15 at 18:16
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    $\begingroup$ @dotancohen Because if it was, then you would guarantee no survivors, ever, in a decelerative crash. In most crashes, everyone dies or everyone survives. In the other (very very rare) cases where some survive, they generally survive because the aircraft crumples, bends and breaks apart which absorbs a lot of the crash energy. Build the plane so that it remains intact (forget about weight, cost and engineering feasibility) and you guarantee to kill everyone with the G forces which result. In summary, building the plane out of something that won't break, would reduce survival rates. $\endgroup$ – Simon Jul 7 '15 at 18:44
  • $\begingroup$ @Simon: Actually (judging from having read a great deal of NTSB reports), most fatalities in crashes where some of the occupants die and some survive appear to result either from postcrash (or, occasionally, precrash) fire, or from what the NTSB terms "violation of occupiable space" (i.e., pieces of aircraft or other debris intruding on the occupants), so making the plane less crumply would actually help with crash survivability there; Gs alone are usually only the primary killer when everyone dies anyway (at typical uncontrolled impact speeds, planes tend to shatter rather than crumpling). $\endgroup$ – Sean Nov 21 '18 at 23:27

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