[svsantosh]

Originally Posted by SnS_12

China says, black boxes of the Boeing 737-800 jet damaged

May be it was 'Made in China?'

[aquavivarium]

Originally Posted by tazmaan

Another Boeing 737 crashes in China with 133 passengers.

No clarity yet if its was the 737 Max


https://timesofindia.indiatimes.com/...w/90350699.cms

Pics clearly show missing tail section, and probably thats the only way it can nose dive like this.

Missing tail section due to structural failure is almost impossible even on ageing airplanes.

Also since Data recorder and CVR are in tail section, will be difficult to locate.

Things have been tough for Boeing recently, it will be very interesting to know how the tail got seperated and we might see very strict inspections and groundings of 737 worldwide if a design/built failure is found.

Still flying is one of the safest means of transportation , I have seen aircraft built in factory and the kind of redundancy incorporated is not found anywhere except in aerospace.

[SnS_12]

Originally Posted by V.Narayan

It is quite likely China, as its largest customer has asked Boeing not to divulge details publicly till the Chinese Govt has decided what they wish to share to the public at large.

Boeing stand to not comment on the CAAC statement and rather saying that they would continue to support the crash investigation further adds to the suspicion or maybe they just don't want to jump the gun yet.

Another interesting development is that China Eastern, which grounded its entire fleet of 223 737-800 planes after the March crash, resumed those commercial flights on Sunday, effectively ruling out any immediate new safety concern over Boeing’s previous and still most widely used model.

Since, the preliminary crash report issued by CAAC has no concrete finding for the reason of the crash then why fly these model planes again?

[aquavivarium]

Originally Posted by SnS_12

Boeing stand to not comment on the CAAC statement and rather saying that they would continue to support the crash investigation further adds to the suspicion or maybe they just don't want to jump the gun yet.

Another interesting development is that China Eastern, which grounded its entire fleet of 223 737-800 planes after the March crash, resumed those commercial flights on Sunday, effectively ruling out any immediate new safety concern over Boeing’s previous and still most widely used model.

Since, the preliminary crash report issued by CAAC has no concrete finding for the reason of the crash then why fly these model planes again?

Precisely because of NIL concrete evidence, millions of hours of safety record can't override one case. That will be killing the industry.

[Freespirit27]

Originally Posted by Rodie09

I always wonder that in this day and age of seamless connectivity, why the black boxes have to be physically onboard the planes? Or at least as a back up there should be something sent to remote location/cloud as much as possible.

A very valid thought, but unlike most populated and manned areas of the world there are still areas where networks are patchy or non existent. Moreover industry standards cater for all kinds of users including military private etc where transmitted data to cloud or servers may not be desirable or prohibited. Civil airline like the MH370 case shows aircraft can still disappear despite all the tech. Moreover any amount of networking will not be foolproof. Typically the black boxes preserve data, untampered, for analysis once the owner agrees to provide it for analysis or rules mandate it, like the accident investigations. There may even be legal implications to prevent owners from tampering logs or corrupting data.
All said, you never know in the connected world how much of data is still getting milked during service and repairs. OLA has revealed some startling data for a simple two-wheeler, imagine what a aeronautical company might be able to extract without owner knowledge

[dsr001]

Just remembered that Malaysian Airlines MH370 wreckage was not found, crash in 2014. I feel it might have entered a similar nosedive. And if that happens over sea, most wreckage cannot be found. That also was a Boeing plane (777) and most passengers were Chinese, like this China Eastern MU5735.

[vinya_jag]

Originally Posted by Rodie09

I always wonder that in this day and age of seamless connectivity, why the black boxes have to be physically onboard the planes? Or at least as a back up there should be something sent to remote location/cloud as much as possible.

Originally Posted by fhdowntheline

I think the problem is with the data volume as well. Recording approximately 120 min of voice/noise and transmitting it real-time could be a challenge.

Originally Posted by sandeepmohan

Using a basic example of the ever popular mp3 format, even if you push it up to 320 kbps, which is usually seen in higher quality audio recordings (We do not need it in this case), 2 hours worth of a recording should work out to <300mb of data transmission. Lets make that 2x, worse case. Using modern data transmission systems, that's a spec in term so size.

Considering Musk's StarLink moves terabytes of data quite easily, it should be possible to do this.

Agree to the Audio example, that a stream of Audio data, even with a lot of duplication, to ensure loss free transmission, doesn’t take a lot of data, and it is absolutely necessary to send cockpit audio data back to base, real time. I’m sure this is already being done.

But, the black box must be storing tons of other data. Video grabs from all the cameras at 30frames per second, temperature data from a few hundred sensors all along the body and the engines, wind data, wing movements, and their response times to pilot inputs, Autopilot decision making process, Cabin pressure, outside temperature, inside temperature etc etc.

Everyone does it. Only Critical or Error logs are stored and transmitted for real time alerting, but all other lower level logging is only present on the device. I’m guessing that those countless decision making computers dump all their data onto the Black box, which would in itself have to be cleaned once in a while.

There possibly would be some data to know what caused it, but the black box would only confirm. It could also be to buy time, before jumping to conclusions.

Having said this, I’m sure the investigators already know a lot about the crash, even without the black box, unless there was total loss of communication minutes before any alarms were raised.

[fhdowntheline]

Originally Posted by dsr001

Just remembered that Malaysian Airlines MH370 wreckage was not found, crash in 2014. I feel it might have entered a similar nosedive. And if that happens over sea, most wreckage cannot be found. That also was a Boeing plane (777) and most passengers were Chinese, like this China Eastern MU5735.

If the plane went into a steep dive, the wings and tail would have broken up on impact and floated somewhere in some time (like the Air France 447 tail).

[dsr001]

Originally Posted by fhdowntheline

If the plane went into a steep dive, the wings and tail would have broken up on impact and floated somewhere in some time (like the Air France 447 tail).

Hi.

AF 447 was not in a steep dive at all.
It couldn't recover from its stall. As per investigators, it resembled the normal orientation at the time of touchdown in the sea, just that was falling down at a reasonable velocity.
https://en.m.wikipedia.org/wiki/Air_France_Flight_447
Thus AF 447 wreckage was sure to be found sooner or later; same for the mortal remains.

MH370 on the other hand, could have gone into a steep, vertical descent, disappearing from radar views very quickly and entering the sea like a vertically dropped knife

[sandeepmohan]

Originally Posted by SnS_12

Some one had posted on Quora the below response he received some 7 years back when he had written to FAA and NTSB

I'd say we had the ability to stream and do it all even 7 years ago. Its a matter of cost and who pays the bill. YouTube pushes >500 terabytes of data a day. I doubt if there are as many aircraft as humans on the ground to stream that much data to some remote Cloud service provider.

Anyway, I make this sound easy. Could be other logistical hurdles (definitely not capacity) and data security being a hurdle.

[Jeroen]

Just a few thoughts on the various comments on why in this day and age, we still rely on onboard data recorders and don’t use some sort of data stream from the plane to the cloud. (Simplified). The total volume of data, all planes 24/7 is vast as already mentioned.

The other factor, there are simply no reliable streaming technologies that will insure 100% data integrity on a moving plane. You will need to use satellite technology, mobile networks won’t do. Current satellite technology does require specific orientation of the antenna towards the satellite. When a plane is in cruise, flying pretty stable not a problem. When a plane banks normally it might already disrupt the transmission. Inmarsat for instance is particular sensitive.

In the case of this particular crash, with a very rapid descent, it is unlikely that a data link, based on satellite, would have been able to continue the data stream. The plane was going down fast, most likely oscillating and moving about multiple axis.

There are no seamless handovers between satellite systems either (as in Mobile telephony system), so you might have some disruption switching from one to the next. Not sure if we have a true global communication satellite coverage system in place. Although in theory and going by their PR there is, my own experience with satellite phones is they just don’t work everywhere. E.g. 100% coverage of the earth 24/7? There are also several places/countries that actively block satellite communication. So there are quite a few technological and regulatory challenges to overcome.

So it will be a while before aviation authorities would be certifying a data stream service for onboard data recording.

So having a very robust recorder on board, in fact there are multiple, is still the most reliable way of getting data out of a crashed plane.

Jeroen

[mazda4life]

Originally Posted by svsantosh

May be it was 'Made in China?'

Usually it’s manufactured by Honeywell which is a major oem supplier for both Boeing and Airbus.

[Jeroen]

China Eastern Black Box Points to Intentional Nosedive
Flight data suggests someone in cockpit pushed Boeing 737-800 into near-vertical descent, according to a preliminary U.S. assessment

https://www.wsj.com/articles/china-e...ve-11652805097

Or

https://www.theguardian.com/world/20...says-us-report

Jeroen

[SR-71]

Quoting The Guardian...

Analysis by US officials of the black box flight recorders found amid the wreckage suggests deliberate input from the cockpit forced the Boeing 737-800 plane into its catastrophic dive.

The Wall Street Journal quoted an unnamed source who said: “The plane did what it was told to do by someone in the cockpit.”

The China Eastern plane was cruising at a steady altitude and speed before it suddenly descended more than 20,000ft in just over a minute, and crashing near the city of Wuzhou in Guangxi province.

This is so weird and scary. On one hand the MAX wouldn't listen to valid cockpit inputs (the Ethiopian crash) due to inherent design flaws and crash the plane. On the other hand its older cousin refuses to identify dangerous cockpit inputs and blindly does what the pilot is asking it to do. One would think inputs leading to near vertical descent is clearly identifiable as no-go parameter for fly-by-wire systems, allowing them to ignore such inputs and level out the flight, maybe even send out an SoS to ground control. But again I am no pilot, so can't comment with authority.

[vharihar]

Originally Posted by SR-71

One would think inputs leading to near vertical descent is clearly identifiable as no-go parameter for fly-by-wire systems, allowing them to ignore such inputs and level out the flight, maybe even send out an SoS to ground control. But again I am no pilot, so can't comment with authority.

Not really. There always must be a way for manual override, so I think what the aircraft did is right. If it behaved the way you suggest, then that'd mean there'd be no way to manually override a faulty avionic system, when the aircraft systems *think* that all is well, but in reality all isn't well (say due to faulty sensors, etc)