Australia Issues Postmortem on Seabed Search

flaperon-flotation

The search isn’t officially over yet–the crew of the Fugro Equator still has a Christmas and New Year’s at sea to look forward to, as well as most of the month of January–but it looks like Australia is throwing in the towel on the current seabed search as it issues its First Principles Review looking at what it learned during the last three years and where it thinks the plane’s main wreckage still might be.

The upshot of the report is quite similar to the postmortem posted here in September entitled Commentary on Neil Gordon Interview. In short, the First Principles report argues that the debris most likely is located in a small (25,000 sq km) area to the northeast of the 120,000 sq km search area, and that if it isn’t there, the ATSB has no idea where it is.

Personally, I’d like to see them go ahead and search that area, but as I read the tea leaves Malaysian and China will not allow it. They’re done. (They’ve heard the “we’re absolutely certain it’s in this area but oops it’s not so we promise it’s in the next area” line before.)

So what did the report contain that was new?

What we didn’t learn, to my great dismay, was anything about the biofouling or anything more about the mechanical breakage of the debris, and what it could have told us about how the plane came apart. Patrick De Deckker’s findings might be buried forever.

There were, however, some interesting revelations:

  • For the first time, the ATSB went into some detail explaining just how much of the seabed it might have missed because the seabed terrain was too steep or rough. They reckon this to amount to about one percent of the total.
  • Search team members agreed that “the distance required to be searched from the arc could be reduced to 25 NM from the 7th arc.” At one time officials believed that the plane could have gone as far as 100 nm, so excluding that possibility greatly reduces the search zone size.
  • For the first time, the ATSB has said that the quantity of debris collected in the western Indian Ocean by itself is useful in reducing the search area: “From the number and size of items found to date from MH370 there was definitely a surface debris field, so the fact that the sea surface search detected no wreckage argues quite strongly that the site where the aircraft entered the water was not between latitudes 32°S4 and 25°S along the 7th arc.”

For me, the most exciting part of the report is the section provided by the CSIRO discussing how the debris might have drifted. The piece de resistance is a photograph provided by the French showing how the actual Réunion flaperon floated when put in the test tank (above). There are two stable states, both of which require heavily-encrusted parts of the flaperon to stick out well clear of the water. This is clearly impossible–barnacles can not live high and dry.

In the past, during discussions of this topic on this forum, people have said, “but wave action might flip the flaperon over so the whole thing might stay wet.” I’ve pooh-poohed this, saying that the flaperon looked quite heavy, and riding low in the water it would be no meant feat for a wave to flip it over. But lo and behold, the report contains a fifteen second video of a replica flaperon being tossed around in a choppy sea by 20 knot winds, and by god if it isn’t flipping over all the time. And therefore I acknowledge that it’s easy to imagine a flaperon getting continually flipped over, so that no barnacle would stay out of the water for more than a few seconds. However, what I cannot imagine is that a state of 20 knot winds is going to persist for 15 months. At some point, the wind is going to die down, and all the barnacles on the high side are going to die. Then the wind will pick up, the flaperon will get flipped over, and the barnacles on the other side will die. The only barnacles that would be able to survive such flip-flopping would the those in the band between the two exposed “poles.”

This is a really obvious problem that the French addressed in their own original secret report (though as I’ve written they couldn’t reconcile it). I find it a little surprising that CSIRO didn’t engage in the topic at all. I wish they’d let me write the questions for their FAQ!

As it stands, I feel that the photograph above provides a huge clue as to what happened to MH370.

UPDATE 12/20/16: To clarify this “huge clue,” here are some pictures of the trailing edge, which according to the French tank test should have been sticking out of the water (right-click to expand). (You can see a video of a replica floating in this way here.)