Malaysian Airlines MH370 contact lost

[mm43]

Originally Posted by MountainBear

According to the article below the only ping that originated in the aircraft was the final "partial ping". All the other pings were initiated by the ground station.

That statement happens to be correct. I have found that depending on the volume of satellite Aero traffic, the GES will delay the interrogation packet, and the GES software will reset the next time.

I have also found that the Malaysian fleet have been, or are using the FANS SAT ADSC system, which ensures that the open source ACARS code is actually encoded, and therefore privileged info such as the RR data remains that way. When using FANS, each AES to GES transaction includes a basic lat, long, alt report.

The only RR reports were sent on take-off and top of climb, and were routed via VHF ACARS.

[OPENDOOR]

From the Washington Post article; Malaysia Airlines didn't buy computer upgrade that could have given data on missing flight.

Many major airlines use the full package of Swift options. The detail it provides is mandated under international aviation guidelines for airlines that ply the busy North Atlantic corridor between the United States and Europe. There are no such requirements elsewhere in the world, the industry official said.

But MAS say;

"The need for SWIFT has never been mandated and all our aircraft have what is called the Aero H SATCOM communications systems,” Malaysia Airlines said in a statement. “This installation is sufficient to meet all of MAS’s operational requirements and at the same time meets all international requirements that enable us to fly international airways.”

So are MAS, semantically, incorrect in that they would need the full Swift package if they flew the Europe/USA route?

[bono]

Deep-sea search tools ready for deployment

Deep-sea search tools ready for deployment
Phoenix Towed Pinger Locator 25


Bluefin-21 autonomous underwater vehicle


'Abyss' type deep-sea submarine


The side scan sonar imagery collected by the Bluefin Robotics deep-sea search submersible is capable of capturing great detail

Source:
MH370 crash: Deep-sea search tools ready for deployment - Nation | The Star Online

[500N]

.
Australia's Prime Minister with a representative of every nation involved in the search from RAAF Base Pearce.

As I said before, not often you'll see this lot together and smiling !


Edited
New resized photo

[deanm]

Bono - great pictures.

Could you provide some detail around the last photo (side-scan image(s): what are we seeing, from how far away & what kind of resolution i.e. metres/centimetres per pixel?

[awblain]

etudiant

In US terms, the current guidance is roughly this:
We think an aircraft has crashed about 1100 miles off the coast of California.
Please find the debris. We don't know that there are any afloat, but some may wash ashore, so check the West Coast and the sea bed.

It's a bit more pessimistic than that. Rather, the current detail is "it's somewhere in a 500-mile swath N-S that extends from 1000-2500 miles away". So, keep your eyes open too Hawaii, and watch your beaches Oregon and Mexico.

The Intelsat information is excellent. However, the search guidance seems to be being set by a mix of political grandstanding, and an irrational reaction to satellite photos of freight containers and whitecaps. Tony Abbott says that the search will go on indefinitely: it might need longer than that.

It now seems reasonable to assume that all the satellite information that's going to be available is available, at least to governments, if not to the public, although I find it hard to believe that no-one has some ocean radar satellite data that they can't catch the track of MH370 on. Could its contrail really not be stacked to appear on weather photos taken after dawn over the ocean either? Just a single location enroute would make the search box much much smaller.

If the sonar data recorder detection effort fails, and given the several hundred thousand square kilometer positional uncertainty - that seems likely - it will be a long haul of hoping imaging sonar surveys can locate the wreckage somewhere on the favorably-shaped abyssal plain.

That sonar image in 500N's post shows wreckage, so it's ~100m across with few-cm resolution. If the same can be done with a 5-km swath, and meter resolution, then the wreckage might be found after sailing ~20,000km, which seems to be a bit of a challenge. A spot survey of likely locations based on a coarser survey would seem to be more realistic. Whatever method found the Titanic would seem to be a template, but the location of the Titanic was known to within a few hundred square kilometers: that's about a thousand times better odds for the searchers.

[bono]

Bluefin Sonar Technical Specs

deanm


Could you provide some detail around the last photo (side-scan image(s): what are we seeing, from how far away & what kind of resolution i.e. metres/centimetres per pixel?

The PDF at http://goo.gl/oN0wp6 has some useful technical info. Else try www.bluefinrobotics.com.

[glad rag]

Nice flat sea bed there...... same as "latest" idea where it went down..the linked article is quite interesting indeed..





Ref.. http://newsinfo.inquirer.net/590562/...-with-1-trench

[Daermon ATC]

First of all, my apologies if my question is just plain wrong or absurd, I'm no pilot just a lowly atco.


Broadly speaking the two concievable scenarios are either some sort of combined mechanical failure or intentional misdirection of the plane. In the former scenario a constant magnetic heading has been proposed as an explanation of why the plane should have ended close to Australia.

If the latter scenario is correct the method could be the same but it also allows for a conscious and able person piloting the plane. In that case the logic for crashing the plane in the southern indic ocean would be to severely difficult any recovery efforts.

The last two search areas have been calculated from a series of automatic signals with several assumptions about constant direction, speed and altitude, I believe.

However, if there was somebody piloting the plane who knew about these signals and could not disconnect them like the ACARS and the transponder then these assumptions might not be correct.

For example, if after about 5 hours of flight the pilot would simply turn 180 degrees, fly that track for half an hour, turn 180 degrees and repeat untill fuel exhausted... wouldn't the relative angle to the satellite still be about the same?

My point here is that if somebody intentionally made that plane disappear then he might have taken further steps to avoid this plane ever to be found.

[Pontius Navigator]

Originally Posted by Daermon ATC

For example, if after about 5 hours of flight the pilot would simply turn 180 degrees, fly that track for half an hour, turn 180 degrees and repeat untill fuel exhausted... wouldn't the relative angle to the satellite still be about the same?

The relative angle would be the same. The point is, AFAIK, it wasn't.

According to Inmarsat the aircraft exhibited a consistent track away from the satellite. The Doppler would have been negative, the time delay would increase.

In your scenario, while the Doppler shift may also have been negative the time delay and angle would have remained constant.

[NigelOnDraft]

I think it fairly safe to assume nobody, including Inmarsat, quite understood the implications (or even presence of) the "pings" and the subsequent analysis. A scenario where somebody aimed to "fool" the process is, IMHO, unlikely.

[Shadoko]

In your scenario, while the Doppler shift may also have been negative the time delay and angle would have remained constant.

It's seem there are only "delta" values, not negative ones: if negative was possible, the path towards the sat (from "disappearance" to west of Malacca Straits) have to be also negative.

For example, if after about 5 hours of flight the pilot would simply turn 180 degrees, fly that track for half an hour, turn 180 degrees and repeat untill fuel exhausted... wouldn't the relative angle to the satellite still be about the same?

The sat data give a speed (Doppler) but also a distance (in and out signal). So, with your guess, the last "arc" couldn't be 40° but a smaller value.

All this from I have understood...I

[onetrack]

AMSA has reported that the four promising orange objects sighted yesterday are fishing objects, and have nothing to do with any aircraft.
The search goes on. The weather today was scattered low cloud with a few isolated showers - the next 5-6 days are promising to be excellent weather, with minimal cloud and fine conditions.

ADV Ocean Shield has left Garden Island port this evening to do a test run with the pinger locator.
If the test run produces satisfactory results, she will leave later tonight for the search zone.

[500N]

Further to my photo above, people might be interested to know that 550 people are involved in the Search from RAAF Base Pearce near Perth in Western Australia.

You can then add the AMSA staff in Canberra and support people at Garden Island Naval Base and on ships.

I reckon you'd be looking at 1000 people or maybe more.

[awblain]

There are two pieces of information -

i) the Doppler shift, revealing the instantaneous speed along the line between the satellite and aircraft during the "ping". Various three-dimensional velocities are consistent with this line-of-sight speed.

ii) the round-trip timing of the "ping", giving the distance between the aircraft and satellite during the "ping". A whole arc of positions on the Earth's surface are consistent with this distance.

If the aircraft turned around, then the rate of change in the timing distance would have reversed, and so would the sign of the Doppler signal, becoming higher in frequency instead of lower as compared with the broadcast frequency from the aircraft.

That the Doppler shift didn't change sign all the way to 0811, based on the Straits Times' excel figure, means that the aircraft probably crashed still heading away from the satellite.

However, after 0811 it could have turned, as there was no subsequent satellite data to check that.

[bsfish2003]

Search areas

I suspect that, which ever areas they searched in the southern Indian Ocean, they would find debris similar to that which is currently being found.

[Lonewolf_50]

Chronus

I find it surprising that the US Navy has not tasked an aircraft carrier to assist. The avialbility of such vessels would greatly assist by substantially increasing time over the search area conducted by carrier based aircraft.

Not effective application of that asset.
I am not at all surprised that the US has NOT assigned a CV/CVN to this effort. Further that point, with the large degree of uncertainty involved in any localization effort, there is no reason to steam a national asset of that particular capability out into the middle of nowhere.
None.

awblain

The visual search for items three weeks after the crash seems to be a waste of time, and even if anything is found, it will be less helpful after all the drifting it's done in terms of locating the data recorders than the Inmarsat data.

Not a waste of time. As you and others have noted, all of this stuff is related to probabilities, not certainties. It is called "search" for a reason. People DON'T know where it is, and the probability areas based on such information as is available are large, not small. Put a different way, the areas of uncertainty are large. Is one searching in a circle/oval with a radius of about 20 nm, 200 nm, or 2000 nm?

The drift can be calculated to provide some pretty good best estimates of a vary good localization area. There have been a lot of posts that show the various ocean research buoys that are tracked to learn of current and drift in oceans all over the world.

[awblain]

Lonewolf,

It's been about 550 hours since the disappearance. How accurate a tracked-back position is even a large number of drifting fragments now going to provide realistically?

To try to be positive, currents have been traced by buoys; however, each floating object will interact with wind and waves in a different way, and it's quite possible that debris has travelled over 1000 miles from where it went into the sea.

Given the uncertainty in the crash location is currently a box that is up to 500 x 2000 miles in extent, I agree with you that almost any more information would be better than nothing, and if it's providing useful training for the crews doing the search, and no searchers get hurt, then it's probably harmless; however, it seems to me to be reaching the point that potential returns from finding flotsam using anything other than a beach are diminishing.

Again, to try to be positive, the discovery of a sure-fire-from-MH370 item out in the ocean would provide a firm limit to the easternmost position of the crash, and given that the uncertainty about range beyond the 0811 satellite contact also remains large, it would still probably constrain the N-S position, but it's not getting any more accurate with time.

Is there anything else to do? I suspect that looking hard for a contrail using stacked weather satellite data after dawn as the flight neared its end might be a way to go at this stage, because at some point, criss-crossing the ocean looking for surface debris is definitely going to stop being useful.

[Ian W]

Lonewolf,
I think you are missing a point. Just the discovery of a windb lown seat cushion or galley items that were indisputibly from MH370 would settle a whole lot of arguments. It would show that the aircraft had crashed in the southern ocean and was not in one of the 'stans. There would be some closure (not complete) for the families, Israel could relax more, etc., etc., Then the vagaries of drift would be investigated by an entirely different team of experts and a new type of search would start.

[tdracer]

Quote:
I find it surprising that the US Navy has not tasked an aircraft carrier to assist. The avialbility of such vessels would greatly assist by substantially increasing time over the search area conducted by carrier based aircraft.
Not effective application of that asset.
I am not at all surprised that the US has NOT assigned a CV/CVN to this effort. Further that point, with the large degree of uncertainty involved in any localization effort, there is no reason to steam a national asset of that particular capability out into the middle of nowhere.
None.

According to a discussion on the radio while I was driving in this morning, the US had volunteered to assist in the search shortly after the aircraft went missing, but were politely declined since the Malaysians figured they could handle it.
Now that Australia is heading up the search, the US has been requested to provide any and all assistance possible.

Also saw this on Reuters the morning:

The Ocean Shield, an offshore support vessel that will be carrying the ping-detecting device, was supposed leave Perth on Sunday, but its departure was rescheduled for Monday, officials said. The ship will also be carrying an unmanned underwater vehicle.
But the ping detector’s utility, in the absence of more specific information about the location of the wreckage, is questionable. The device will be towed behind the ship at no more than about five knots, or about six miles per hour, and needs to be within about a mile of the black boxes to pick up the signal reliably, making for a slow and painstaking process. The new search area, which was established on Friday, is roughly the size of Poland.