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Ocean Microphones May Have Recorded Lost Malaysian Jet's Crash (livescience.com)
89 points by sagitariusrex 23 days ago | hide | past | web | favorite | 40 comments


“Unfortunately, the acoustics generated by the impact of MH370 on the ocean surface would not propagate along the “deep sound channel” (DSC) the way an underwater acoustic event does, so the impact likely was not detected by CTBTO sensors.” - suggests this is unlikely, although not detailed explanation

They probably don't have the money or influence to get a search crew out there and are hoping this report will encourage some other treasure hunting group to check it out and confirm/reject their theory.

"But just how long the Boeing 777 jet could have stayed airborne would depend on its actual flight path, its altitude and how many of its four engines were operating."

Don't the 777s have 2 engines?

Yeah, that jumped out at me too. I don't know how you get that fact wrong.

3 including the APU

The APU on a 777 provides truly negligible trust; the exaust from the APU is on the left side, not centered, so if it were providing meaningful thrust it would inducing a yaw moment.

I think the point is that it draws fuel which reduces the endurance by a small amount

I'm pretty sure the generally accepted meaning of an 'engine' in the context of powered flight is 'a thing that provides thrust' and not 'anything that consumes fuel'

The APU is for electric power on the ground, it is not used in flight.

...except in emergency situations. Starting the APU was one of the first things they did during the “Miracle on the Hudson” incident IIRC. It’s conceivable that some in-air emergency happening prior to the loss of communication would have required starting it as a checklist item.

EDIT: I just wanted to add that aside from electrical power, it provides bleed air necessary to start the engines, run de-icing (also run A/C packs, operate toilets, etc.) —Hence its usefulness in an emergency situation.

I think we have agree to rule out that any of the problems affecting this situation resemble an emergency.

It can only be flagrant sabotage, or a blunder compounded by savage incompetance.

Either they fucked up so bad that they didn't just shoot themselves in the foot, but instead blew their whole leg off. Possible with hypoxia scenarios.

Or someone sealed the fate of that flight in cold blood. This version narrative includes the premise of suicide, including single-handed, lone wolf pilot suicide, although other nefarious possibilities fall under this umbrella.

The predominant fact of the outcome is that they flew so far off course, and without any distress signals, that their ultimate fate passed into history as a near total enigma which essentially requires strenuous effort or fantastic misfortune.

In some unusual scenarios the APU may be used during flight. If one of the engine's generators fails the APU might be used to help provide power, and below some altitude the APU in the 777 can provide additional bleed air.

In the 777 the left and right hydraulic systems are powered by the left and right engines, but the center hydraulic system has electric and pressurized air driven pumps that I believe can be run off the APU: http://www.flight-mechanic.com/wp-content/uploads/2017/11/12...

If MH370 lost engine power, maybe it was using the APU to keep the control surfaces active? Who knows. In that sort of situation the 777 would be a glider though.

4 including the Ram Air Turbine (RAT)

The RAT is not an engine and doesn’t deploy unless all other engines have shutdown in flight, and it induces drag because it’s a kind of ‘wind turbine’ that drops into the airstream and generates electrical power (and maybe hydraulic pressure)

You got that backwards; it “powers” hydraulics, and in some (uncommon) cases, supplies electrical power to other systems.

The RAT is an expensive windmill, not an engine.

Yes, they do.

I'm surprised that no mention was made of the U.S. Navy's network of hydrophones (SOSUS) and whatever took its place in the late 1990s. SOSUS was quite successful at detecting a number of Russian submarines since the 1950s with every new generation thereof. In any event, I can only imagine that there would be U.S. government resources (military and otherwise) that could have provided some surveillance information on what happened to the Malaysian 777 airliner.

I wonder how much information, if any, is withheld by military organizations in various countries. I presume a particular country doesn’t want to give away their latest radar capabilities or what have you by disclosing tracking information whether it’s through satellite systems or through sub-ocean sonar.

You don't have to disclose capabilities in a press release honestly unless you really, really need to convince people that you're not falsifying the information or trying to mislead people - there is almost no incentive I can think of to mislead people on a general civilian search mission though. A government could simply point some lowly persons to the general area without any explanation of its methods, put almost no official support in funding the search, and it could relieve a great deal of pain and suffering should it lead to findings. The issue may come down to all the scrutiny that could happen were the information lead to the discovery of the plane and (presumably) its passengers. I'm not aware of any government issuing statements like this though in any capacity honestly. It is probably better to assume that our governments, while powerful, are not without their limitations whether it's bureaucracy, technicalities, or simple funding limits.

> it could relieve a great deal of pain and suffering

I confess I don't understand this. The families know how their loved ones died, when, and sort of where (in the ocean). How does knowing the precise location help any?

I think the rituals around death aren't complete without a story. It's the reason why before they tore down the eastern span of the Bay Bridge that let the families of people that died on the bridge visit the spot where they died.

I understand wanting to know more details. But having gone through rituals around death of someone close myself, it doesn't ease any of the pain.

I've also wondered about those families attending the execution of the person who murdered their loved one. I doubt it eases their pain and suffering in the slightest.

It’s almost like feelings are a very subjective matter and not the same for everyone. Not everyone thinks the same way as you do.

> I wonder how much information, if any, is withheld by military organizations in various countries.

Ooh, I can answer that. All of it, unless forced to disclose by political factors. There is no upside to the military to releasing anything, ever.

HN is a geekfest, and I'm a geek too. I could not, and still cannot, comprehend how resistant to the "helpfulness instinct" a military man is. I, by my very nature, cannot resist helping people whereever i can, and offering whatever information I might judge useful whenever I can. The military [1] is the exact opposite of that. It's hard to get your head around.

I have zero doubt that one or more militaries in the area, especially Singapore, know exactly where MH370 went, or at least what direction it eventually took off in. Every radar in the world is recording 24/7. They have no incentive whatsoever to divulge what they undoubtably know. We'll find out in a few decades, probably.

[1] and many large corporations.

> I have zero doubt that one or more militaries in the area, especially Singapore, know exactly where MH370 went, or at least what direction it eventually took off in.

There were so many cranks producing ideas where MH370 went, they could have just used one of those as a front by "backing" a theory that happens to be nearby the point where they have to search, gently nudging the search closer to where it really is and score tons of points for being first in a huge international search effort.

What I was trying to get across in my comment is that the military, in general, does not care in the slightest about those "points". They will not release anything unless specifically and explicitly forced to and needless to say they have not been. They are quite happy to watch other governments, or even their own government, waste millions of dollars looking in the wrong place. Correcting them is not in their mission statement and, frankly, not even part of their thinking.

The whole area is one of the most densely packed geopolitical zones in the world. It beggars belief that multiple parties did not observe, in detail, the whole thing. It was not a stealth aircraft. Fucking Australia probably saw it. I am quite certain Singapore did.

Like I said, we'll probably hear all about it in a few decades.

> or even their own government

I guess it depends on the relationship between government and military, but how common is it for the government to ask all its appropriate organizations (intelligence services, military, weather service, semi-military maritime research orgs) if they have anything about it and for all those organizations to lie?

Why would they risk it? Even if the risk was a 0.001% chance, the cost of losing that bet is infinitely higher than keeping their mouths shut. There is no upside for a military to disclose that information. It's all risk, with no benefit. Militaries aren't people, they're political organizations with lots of secrets that need keeping.

You probably said it better than me. There is no upside, only downside, and applying our own "reasonable human" intuitive standards to such organisations is totally inappropriate.

> All of it, unless forced to disclose by political factors.

Here's a list of DoD press releases: https://dod.defense.gov/News/Releases/

It lists around 500 just in the last year. I don't quite see how "Navy to Christen Guided-Missile Destroyer Frank E. Petersen Jr." would fall under "forced disclosure due to political factors".

I know it's fun to daydream of that perfect organisation constantly updating its "threat actor assessments" and how your speech was really what made the difference in going to Force Protection Condition Medium.

But seriously: the DoD has dozens of press staffers and the phone numbers of people that could pass on a tip under the radar. They have ongoing as well as incident-specific efforts to coordinate with civilian efforts. They regularly pass along environmental measurement data collected from ships, airplanes, and satellites to support research, weather forecasting, or disaster preparedness.

SOSUS (according to the public maps) is very focused on the Pacific and Atlantic oceans and a lot around Russian territorial waters. The network is probably a bit denser than represented on the map but there's not much need for it in the Indian Ocean.


(according to the public maps) is a good disclaimer to add. If you believe those maps, they are basically disregarding the Persian Gulf for example, to a degree that I find wildly inconsistent with the volume and intensity of US diplomatic, political and military intervention in the area. I strongly suspect they've got the whole area mic'd, but under a new program that's "deployment-specific" and more secret. But if they were to offer their observations to the search effort, they would be exposing the existence and possibly the locations of any hydrophones.

I'm not so sure SOSUS is largely an anti-submarine tool and the main countries the US would worry about tracking with subs are Russia and China.

Part of the problem is the area is like the ultimate backwater.

>But the ocean is a noisy place, and Kadri said the underwater sounds might have also been caused by underwater earthquakes...

Seismic is rough. Even large earthquake events are localized with large error because of constant noise - seismic event arrivals are hard to pinpoint precisely in time. On top of that, once we have arrival times from a bunch of seismometers(microphones) localization is an inversion problem, dependent on velocity models for a rather heterogeneous earth which further reduces location precision. Even worse, I doubt a crashing jet produces a large magnitude (loud) seismic event, so picking out its arrival in noisy mic data is even harder than it can be for shallow earthquakes.

I'd guess a radius on the order of thousands of miles at best, but it's all contingent on how loud the event was and how noisy the mics that picked it up are.

For the curious, & because I did the math for myself:

1k mile radius is 3.14 million square miles. The oceans are 140 million square miles.

How frequent are these gravity events during a time period when an airliner isn’t crashing?

Previous analysis of CTBTO hydrophone data (augmented with IMOS, Australian SOSUS clone) back in 2014: https://www.nature.com/news/sound-clue-in-hunt-for-mh370-1.1...

With all those satellites in the air, they should able to trace it.

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