Search crews in the remote southern Indian Ocean have completed a task so vast and technically ambitious that it once seemed impossible: to scan a three-mile-deep, 120,000 sq km swathe of seabed using a side-scan sonar “towfish” in hopes of finding the wreckage of missing Malayia Airlines 777 MH370. After considerable delay due to mechanical problems and bad weather, the final square miles were scanned on October 11 by the research vessel Fugro Equator. The $180 million project turned up no trace of the missing plane, though searchers did find several long-sunken sailing ships.
The Fugro Equator will next use an AUV, or autonomous sub, to scan selected areas where the rugged seabed topography was too rough for adequate imaging by the towfish. “The total combined area of the spots that will be surveyed with the AUV is very limited, but still required to ensure that no area has been missed,” says Fugro spokesman Rob Luijneburg.
The Australian National Transport Board (ATSB), which is overseeing the search, expects this fill-in work to be completed by the end of February.
The fact that that the Pennsylvania-sized towfish scan had been completed was first noticed by Richard Cole, a space scientist at University College London who has been meticulously logging the search ships’ movements via online tracking services and then posting charts of their progress on Twitter. “At the completion of Equator’s last swing in mid-October the target of 120,000 square kilometers had been achieved, at least as far as my calculations show,” Cole wrote me last week. Both Fugro and the ATSB subsequently confirmed Cole’s observation.
The 120,000 sq km area has special significance in the effort to find MH370, because ministers from the four countries responsible for the search have made it clear that if nothing turns up within it, the search will be suspended. Unless new evidence emerges, the mystery will be left unsolved.
Plans to search the seabed were first mooted during the summer of 2014, after officials realized that metadata recorded by satellite-communications provider Inmarsat contained clues indicating roughly where the plane had gone. At first, investigators were confident that the wreckage would be found within a 60,000 sq km area stretching along the 7th ping arc from which the plane is known to have sent its final automatic transmission. When nothing was found, ministers from the four governments responsible for the search declared that the search zone would be doubled in size.
In December, 2015, officials declared that the search would be completed by June, 2016. In July of 2016, Malaysia’s transport minister indicated that it would be finished by October; weeks later, a meeting of the four ministers pushed the completion back to December. Last week, the Australian Safety Transport Board announded that “searching the entire 120,000 square kilometre search area will be completed by around January/February 2017.”
In an email to me, ATSB communications officer Dan O’Malley said his organization will issue a report on the seabed search once the full scan is completed. Under ICAO guidelines, Malaysia will only be obligated to release a comprehensive final report on the investigation once it has been formally terminated; so far, Malaysia has only talked of suspending the search, not ending it.
The bulk of the work has been carried out by ships pulling a sidescan sonar device on a long cable. This so-called “towfish” uses reflected sound waves to create an image of the sea floor. By sweeping up and down the search zone in much the same way that a lawnmower goes back and forth across a lawn, searchers have been able to build up a comprehensive image of the search area’s bottom.
But, just as a landscaper might have to use a weedwhacker to clean up areas around rocks or stumps, searchers will have to fill in gaps in the scan where underwater mountains, volanoes and escarpments have prevented the towfish from getting a close enough look.
“A total area for search by the AUV is difficult to give because it concerns a number of relatively small spots that all are relatively difficult to reach and in difficult terrain,” Luijnenburg says.
The fill-in work will be carried out by an Autonomous Underwater Vehicle deployed from the Fugro Equator. The Kongsberg Hugin 100 is capable of diving to depths of up to 15,000 feet and can maintain a speed of 4 knots for up to 24 hours before being retrieved by the mothership. Whereas the side-scan sonar of the towfish has a resolution of 70 cm, the AUV’s sonar has a resolution of 10 cm, and so can image the seabed in much greater detail, as well as taking photographs when necessary.
Meanwhile, as the AUV work progresses, a Chinese vessel will deploy an Remotely Operated Vehicle (ROV) to take photographs of targets previously identified as being of interest. The ATSB has stated that none of these targets are “category one” targets, namely those likely to have come from MH370, however. Says Cole, “In the absence of category one targets there must be a list of targets from the sonar search that look the most interesting, so the question is how far down that list they are going to go.”
While the fill-in work must be carried out in order for the work to be declared 100 percent done, little prospect remains that the missing plane will be found in the southern Indian Ocean.
NOTE: This story was updated 10/26/2016 to include comments from Fugro spokesman Rob Luijnenburg.
@JS
Yes, I wrote that. I still strongly believe the Inmarsat data is valid, both BTO and BFO (subject to a realistic understanding of oscillator physics).
Equipment resets, such as happened at 18:xx, can produce anomalies. I was merely suggesting how one could have occurred. I am satisfied that the most likely interpretation of the data is the mainstream interpretation.
@All
Australian newsfeed 2Nov16-1453 DS EST hrs
http://www.news.com.au/world/new-mh370-analysis-suggests-no-one-at-controls-during-crash/news-story/c3032e2dbc8d0fdcfeefebb0afdfe5e1
Cheers Tom l
New Operational Update, https://www.atsb.gov.au/mh370-pages/updates/operational-update/
Still maintains 110,000 km searched.
Mentions there will be a report “in coming months” on the current 3 day review.
@All
Trying to look up new sources. Plus a few points.
1. If one of those states in that coalition group for that area Mal-Thai etc
knows what happened they should all know.
2. Have the French released any info yet? I might have missed it. I know
they were pretty pissed off with Malaysia.
3. These links ( with more to come) do provide an insight to what the can do with the Sat Tech.
Just because you are sitting in a internet coffee joint downtown somewhere
they have got you covered and send in the’ Boys’ or a drone.
Satttrack Blog
Comment by Lee Graham very interesting!
http://sattrackcam.blogspot.com.au/2014/03/satellites-and-malaysian-airlines.html
http://sattrackcam.blogspot.com.au/2015/11/flight-mh17-satellite-data-and.html
http://sattrackcam.blogspot.com.au/search/label/Mentor
Sorry a lot of reading but difficult to precis.
Cheers Tom L
@Sk999
>Figures 10 and 11 of the new ATSB report suggest that the favored starting locations for the flaperon and other debris are the yellow and white zones.
Surely, as written the report rules out all the zones in figure 10 except yellow, purple and black. If implemented this would extend the search area to 30S.
The report sticks with the gold standard width of +/-40nm. To thicken the north part of the current search area to this figure, and extend to 30S would need an additional area of 110000sq.km., just less than that achieved to date. That doesn’t sound practical, even if it based on statistically significant grounds. I guess the meeting now in progress has to address that issue.
@All
IMO also quite important is the conclusion the flaperon and outboard flap section seperated on impact, not in flight or during descend (due to flutter). IMO this suggests a not very high impact speed considering the relatively undamaged state the flaperon and outboard flap section are in.
I’ve taken a closer look at the outboard flap stiffeners that are damaged figure 15, 16, 17, 18 and it makes me doubt the outboard flap was fully retracted on impact.
As well the upper as the lower shown stiffener show damage.
IMO that upper-stiffener (figure 18) could not have been hit and bend that way by the support track if the outboard flap seperated upwards on impact fully retrackted.
This upper stiffener-edge is also bend backwards which is telling IMO.
IMO this can only mean the outboard flap was partly deployed at maybe ~10 degrees with the support track-end behind this upper stiffener.
On impact the flap would have been pushed upwards and towards the end of this support track which then hit this upper stiffener bending it backwards.
Further upward movement of the outboard flap then caused the support track to hit the lower stiffener denting it before seperating completely.
@Richard Cole
You said “Surely, as written the report rules out all the zones in figure 10 except yellow, purple and black. If implemented this would extend the search area to 30S.”
but the report says “drifters from the red and yellow areas have begun to make landfall on the African coastline” after 8 mths and I took that to mean the red, white and yellow areas, so presumed that areas south to ~34S in the diagram are ruled out, leaving only the purple and black areas which have been searched already. Thoughts?
@AM2
You are correct that the caption for figure 11 states that, but the text states “A significant number of red drifters have already reached the coast of Madagascar and mainland Africa… This suggests a reduced likelihood of debris originating from the northernmost areas shown in Figure 10 (red and white coloured regions).”
Examination of figure 11 shows a lot more white than yellow markers west of Madagascar. I don’t think we can resolve this from the report, but agreed that whether the yellow area is consistent with the drift data is a key point.
Some other points on the new Report.
Change of heart:
The mention that there can be engine restarts suggests these could consume fuel otherwise available to the APU, which I have raised with them and on this forum. Yet they still suppose a log-on 2 minutes after fuel exhaustion, indicating that they believe the APU will have fuel for this.
They then go on to state, “In the simulator, when the fuel tank is empty, zero fuel is available to all systems fed from the tank. However, in a real aircraft, various aircraft attitudes may result in unusable fuel (usually below engine/APU inlets) becoming available to the fuel inlets for the APU/engines. If this resulted in APU start-up, it would re-energise the AC buses and some hydraulic systems. This could affect the trajectory of the aircraft. Similarly, the left and right engines may also briefly restart, affecting the trajectory”. I cannot reconcile an APU start up, needed for the log-on being consistent with, “If this resulted in APU start-up…” I hope the review does. I presume they do not mean a second APU autostart.
Observations:
In passing, the highest BFO (Case B) descent rate would be increased were the ambient air colder than the previous 9M-MRO logs-on they use as a datum for OXCO drift, ie the cabin was extremely cold through depressurisation after engine bleed air was turned off.
The flaperon had contacted the outer flap during aircraft break up. They do not say whether in the air or on hitting the water (Ge Rijn: at least that I can find). I think flutter is ruled out but not in-flight break up outside the envelope; wing breakage for example. If its separation was on hitting the sea in other than a dive, its near-neutral position together with both it and flap being housed would mean it was not deflected as an aileron, which (as distinct from the left flaperon) it would have been under RAT power had there been bank. Non-deflection would be odd since the outer flap, in apparently being broken upwards-at-the-rear (the cracked inner rib) and with the width of the rear section lost being wider at its outer end, suggest the right wing would be low – that flaperon being deployed downwards.
Weaknesses:
Alluded to are some new simulation runs which support the possibility of the high final BFO descent rate. There is a statement that some of these have descents which might go outside the simulator data base (“should be treated with caution”) and some were outside the flight envelope, presumably with the outcome likewise being uncertain. They apparently have made some allowance for these unknowns but have not said on what basis.
Also they do to me suppose that the aircraft was un-piloted, without stating that as an assumption. That there was no controlled ditching does not prove that.
Outcome
Great that there is sufficient confidence in the new drift and other data to hope to overcome the constraints previously imposed for extending the search.
@AM2
My own conclusion is that the aircraft most likely came down within the area already searched, the pink(purple)/black area, but has somehow been overlooked.
RE : new report
Something that hit me while reading the new information on drift calculations :
– There is only 2 flaperons on a B777
– It’s quite unlikely that both would break exactly in the same fashion
– It’s quite possible that the 2nd flaperon, either didn’t detach or broke in a way that made it sink.
– So there is only one piece of debris with the exact floatability characteristics being studied.
The fact that no flaperon have been found somewhere isn’t proof that this area wasn’t reachable by the flaperon. It’s just that there was only one flaperon to find, and it has been found!
The only things that could be learned from studying the flaperon are :
– Is reunion island reachable from this starting point?
– Is the speed required to reach reunion island from this starting point compatible with the time frame it was found?
Re impact analysis :
I would tend to agree with the ATSB conclusion that the flap wasn’t fully extended.
Something that can also be noted (as alluded by @Ge Rijn) is that the vertical impact forces where close to nil! Otherwise the lower stiffener would have broken off.
The stiffeners all seems to have been impacted by some object coming from forward.
So the only range of impact scenarios remaining (if we exclude airborne separation) are :
– Ditching with very small vertical speed and the leading edge impacting first
to
– Vertical dive also with leading edge impacting first
The failure of the trailing edge, as well as the general state of the pieces recovered seems to me to be excluding a vertical dive.
We’re then left with low intensity impact or inflight break up.
The main purpose of the new ATSB report seems to be to support the ATSB’s initiaL assumption that the aircraft was flying without human control after the turn south.
Firstly, the ATSB report considers the effect on the recorded 00:19 BFO’s of possible warm-up drift of the oven-controlled crystal oscillator (OCXO).
However, it ostensibly fails to address Inmarsat’s observation in the Journal of Navigation:
Then it considers end-of-flight simulations which assume absence of pilot inputs.
Finally the report analyses damage to the inboard section of the right outboard flap and the flaperon an concludes that the flaps were retracted at impact. According to news.com.au:
However, that ignores the possibility that a highjacker would not have known that flaps cannot be extended after fuel exhaustion to engines and APU.
Closing comments here, please add your thoughts to the most recent post. Thank you.