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I was more than sure that FDR (as good as any other electronic device including magnetic strip, i.e. HDD), after sitting for a few days under the sea or ocean, must unconditionally be transported wet (i.e. inside some water container) to simply not let magnetic strips to get dry. The answers to this related question confirm this.

Yet, I have just saw a reconstruction and investigation of Ethiopian Airlines Flight 409 crash and noticed that:

  • FDR (found and extracted first) was transported dry, enclosed in an empty box,
  • CVR (found and extracted few days later) was transported in a box filled with water.

Is this just a "bug" in movie or can FDRs be transported dry after extracting them from sea / ocean?

fooot
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trejder
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  • I don't believe the issue is the tape "drying out". First it was dry to begin with, second most FDR's use solid state recording devices, not tapes anymore. The bigger issue is corrosion, they need to be carefully washed before they dry so the salt water doesn't destroy the internal parts. – Ron Beyer Dec 28 '17 at 00:21
  • @RonBeyer I'm asking about year 2010 crash. I don't believe that SSD-like solutions were used in FDRs, CVRs seven years ago, but I may be wrong. – trejder Dec 29 '17 at 11:45
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    @all I don't understand your decision. I'm asking, why in particular case FDR was not transported in water and you mark my question as duplicate pointing to an answer that says that is must be carried in the water. How original answer is supposed to answer my question? – trejder Dec 29 '17 at 11:46
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    Completely agree with the OP, this is asking about why in a specific case standard practice wasn't used. – Notts90 Jan 04 '18 at 12:58
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    @trejder: They were, in fact, already in use sixteen-and-a-half years ago. – Vikki May 01 '18 at 00:33
  • @Sean What are we talking about here? You pointed out to a Wiki article's section which says that in AA77 crash a FDR with magnetic tape was used. Which supports my claim that SSDs were not used at that time. What was already in use 16,5+ years ago? – trejder Oct 08 '18 at 08:04
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    @trejder: Quoth the article in question - "On the other hand, all the data from the flight data recorder, which used a solid-state drive, was recovered." My emphasis. – Vikki Oct 09 '18 at 02:47
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    Update: solid-state FDRs have been around since at least 1992 (look under the "Flight Data Recorder" section), while solid-state CVRs have been around since at least 1993 (quoth the second-linked report: "It was the first solid-state CVR that the Safety Board has had the opportunity to read out for an investigation.") – Vikki Dec 09 '18 at 04:36

1 Answers1

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As posted on Avherald, Lebanon's CAA released the final report in January 2012, detailing the investigation and its findings. The link on Avherald is broken, the current site for the CAA can be found here. The front page still links to a page on the report, where it can be downloaded.

Section 1.11 describes the recovery and contents of the flight recorders, and describes both recorders as being "immediately packed in water.".

See this fragment:

The DFDR was recovered from the Mediterranean Sea by the Lebanese Navy divers and turned over to the IIC in presence of members from the IC on 7 February, 2010. The DFDR was immediately packed in water to prevent/delay the onset of corrosion and transported to the BEA laboratory in Paris France under the custody of the IIC accompanied by a Lebanese and an Ethiopian IC members.

And this one:

A thorough hand search of the sea bed was then carried out the Lebanese Navy divers who finally succeeded in retrieving the CSMU and handing it over to the D/ICC in the presence of members from the IC on 16 February. The CSMU was immediately packed in water to prevent/delay the onset of corrosion and transported under the custody of the D/IIC and an Ethiopian member of the IC to the BEA laboratory in Paris France, for readout on 16 February, 2010.

While this could be inaccurate, it's much more likely that the reconstruction missed this point.

trejder
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fooot
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