'Contact lost' with Malaysia Airlines plane

Shouldn't someone at this point have gone "this is definitely a plane black box signal" and thus determined either another plane went missing in the past few hours or this is MH370? Considering the media interest and frankly the nature of who is involved, multiple countries, multiple Navy teams, multiple ships. Surely the signal can be sent to a dozen people within basically minutes to be verified?

Though I can also see the mishandling of the situation making them more cautious about relaying incorrect information this seems pretty black and white. You're either picking up a signal from several thousand feet in the area you think the plane crashed, transmitting on the black box emergency beacon frequency..... or........ Atlantis broadcasts at the same frequency?
 
There is nothing being broadcast by Radio on an emergency signal. It's an ultrasonic pulse that can be picked up by acoustic locating equipment. Once they have the ping they will be able to determine distance and direction and they will be able to follow it until they find the source.

I could be a Russian sub... :)
 
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Tefal said:
you know planes are tube shaped?

ever noticed most pressure vessels are too?


try and think why depressurizing the cargo hold but keeping the cabin pressurized might be a massive engineering challenge
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I can't see an engineering problem. On airliners there are pressurised sections like the cabin and non pressurised sections separated by bulkheads such as the undercarriage. Some aircraft such as Antonov An-12 have an unpressurised cargo hold.
 
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MOOGLEYS said:
There is nothing being broadcast by Radio on an emergency signal. It's an ultrasonic pulse that can be picked up by acoustic locating equipment. Once they have the ping they will be able to determine distance and direction and they will be able to follow it until they find the source.

I could be a Russian sub... :)
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Surely a pulse has a frequency and you would say it is being transmitted/broadcast.

Either way, if it's a signal on the black box frequency which I'm would presume everyone agreed to use for emergency signals so as not to confuse such signals with other sources, then surely it either is at the right frequency and is the black box, or it's not. I'm just surprised they haven't confirmed more widely that they've found the the signal.

I would have thought there was several press rooms full of reporters and the second it leaked on Chinese tv or whatever it was, that everyone would be flooding every other group involved with questions on it.

week's of looking for a plane, desperation, media intrigue, conspiracy theories, mishandling, dozens of countries involved.... may have found the plane and it all goes quiet. Seems completely bizarre.
 
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It's a ping at 35Khz if I remember. It is transmitted as an audio signal not a Radio wave. Same as a speaker emitting a sound. It is emitted every second until the battery runs out. They are guaranteed to last 30 days but generally go on for a lot longer.

The black box is nothing to do with the Sonar Locator beacon they are two different devices joined together. The black box is also not a radio transmitter just a recording device in a protective box.
 
ThundyCat said:
Well the Titanic was over two miles down and they sent unmanned submersibles into the wreck....so hopefully they will be able to do the same with MH370.
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Bismarck is 16,000 feet down an amazingly landed the right way up complete and slid 1.2 miles down an underwater Volcano. Epic Documentry where James Cameron dives to it, incredible to see how relatively intact it is.
 
Housey said:
Bismarck is 16,000 feet down an amazingly landed the right way up complete and slid 1.2 miles down an underwater Volcano. Epic Documentry where James Cameron dives to it, incredible to see how relatively intact it is.
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It's even more epic how intact it is considering how many shells it took before they scuttled it. German engineering at it's best.. :)
 
MOOGLEYS said:
It's a ping at 35Khz if I remember. It is transmitted as an audio signal not a Radio wave. Same as a speaker emitting a sound. It is emitted every second until the battery runs out. They are guaranteed to last 30 days but generally go on for a lot longer.

The black box is nothing to do with the Sonar Locator beacon they are two different devices joined together. The black box is also not a radio transmitter just a recording device in a protective box.
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its also orange not black oddly lol
 
Energize said:
I can't see an engineering problem. On airliners there are pressurised sections like the cabin and non pressurised sections separated by bulkheads such as the undercarriage. Some aircraft such as Antonov An-12 have an unpressurised cargo hold.
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vertical bulk heads are easy as the cylinder maintains strength and there is very little surface area a long horizontal bulk head cutting the cylinder in half is a major issue.

it would add massive weight, and expense and make the plane uneconomical.


think what the psi of a pressurized cabin is and how much area the floor is, that will have to be an icnredably strong floor
 
rubberduck said:
I always assumed they were called a 'black box' because it contained some complex jiggery-pokery that the layperson would not be able to understand.
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So do most people :) They are just a very robust external drives. There is a recording device which is now solid state and a power supply. Then bolted to the outside is the Sonar Locator Beacon.

There is lots of story's on why they are called "Black Boxes" but as boring as it is they are called it because they used to be black.
 
Energize said:
I can't see an engineering problem. On airliners there are pressurised sections like the cabin and non pressurised sections separated by bulkheads such as the undercarriage. Some aircraft such as Antonov An-12 have an unpressurised cargo hold.
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It's not economical to do on modern passenger planes. A simple cigar shape shape with bulkheads is easy to build and lightweight. The same reason airships are the same shape.

Adding different areas of pressurisation means parts need to be strengthened and reinforced which adds weight and takes up space.

Edit - As Tefal said above...
 
MOOGLEYS said:
So do most people :) They are just a very robust external drives. There is a recording device which is now solid state and a power supply. Then bolted to the outside is the Sonar Locator Beacon.

There is lots of story's on why they are called "Black Boxes" but as boring as it is they are called it because they used to be black.
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What did they use prior to SSDs? Presumably magnetic storage right?
 
MOOGLEYS said:
Originally they were magnetic foil which heads scratched info onto alloy foil. Then magnetic wire then magnetic tape before going digital with solid state.
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So why can they only record for 2 hours before having to overwrite old data? I assume with decent audio compression + modern storage capability, capturing data for many many hours should not be a problem.

Is it because the box technology was 'standardised' many years ago when data storage was much more limited?
 
The 777 was introduced in 1995 so although fairly new in aviation terms it's recording technologies are quite old. It is up to the individual operators if they upgrade or implement mods to these systems. Generally most will leave it as it is if it still complies to regulation as it is seen as unnecessary spending.

Newer Aircraft have more advanced systems and better recording systems.
 
rubberduck said:
So why can they only record for 2 hours before having to overwrite old data? I assume with decent audio compression + modern storage capability, capturing data for many many hours should not be a problem.

Is it because the box technology was 'standardised' many years ago when data storage was much more limited?
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An audio CD stores over an hour of music without any compression and that's ancient technology, so there seems to be no technological reason for it.

It's almost as though the black box design were deliberately sabotaged to have such a low recording capacity lol.
 
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The problem is compressing a constant flow of data in real time can be unreliable and requires more processing. The system becomes more complicated and the rate of failure increases.

Tbh I'm pretty sure the 777 DFDR can record approx 25 hours of data I think people are confusing the FDR with the CVR (Cockpit Voice Recorder). Although housed now in one unit they operate independently of each other.
 
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