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2nd black box of crashed China Eastern plane recovered: state media

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I have a sneaky suspicion that what will be reported by the Chinese authorities will be something along the lines of 'the sole cause of this tragedy was poorly made American aircraft.'

I was thinking it will be blamed on Uyghur "terrorism".

0 ( +1 / -1 )

Some sites report that a missing piece of the airplane was found on farmland, so maybe it was a midair breakup

The plane appeared to be in one piece as it dived. There is a video of it crashing. At the speeds and attitude it was in it would not surprise me at all if something came off during the dive. The plane leveled off briefly from the initial long dive. Perhaps something was overstressed and came off then? We don't know yet.

1 ( +1 / -0 )

Why do they still use black boxes in this day and age? If the engines and other parts of the aircraft can communicate with their manufacturers in real time, why not collect all the information that way?

Bandwidth. Engines only send a happy message every half hour. Flight data recorders have dozens of channels recording everything. On top of that you have a cockpit voice recorder. Considering all the airplanes in the sky at any given time it is just too much for the available satellite bandwidth to handle if you are thinking all of it should be recorded in real time by ground stations. There is also the very real possibility that whatever disabled the aircraft disabled their ability to transmit. On board recorders would still be able to capture what happened while that vital information would be lost if there was sole reliance on external comms to transmit the data.

2 ( +2 / -0 )

The plane reportedly recovered from the initial dive and was level or almost so briefly before re-entering a vertical dive. One has to wonder if there was a struggle in the cockpit and a suicidal pilot or co-pilot to blame?

3 ( +3 / -0 )

Although the cockpit voice data recorder is inevitably located in close proximity to the cockpit,

No. it is in the tail of the aircraft where it is more likely to survive a crash.

3 ( +3 / -0 )

Unless something breaks, for the aircraft to go into a steep dive means that the control stick has to be pushed fully forward, either by the flight crew or the autopilot, forcing the elevators fully down and the tail to go up. Once the aircraft has reached the vertical position and the elevators are still fully down, does the aircraft stay in a vertical dive or does it loop back under itself. What I mean is, once vertical, in order to stay that way does the stick have to be pulled back in order to maintain the vertical dive?

I'm not a civil aircraft expert, but I was a flight control software developer in non-civil aviation craft decades ago.

It isn't a simple question. There are too many considerations. The static stability of each aircraft is modified by different flight control deflections, airspeed, wind, angle of attack, thrust, drag, etc. An improperly transferred the fuel load can causing the CG to change. Lots of details. If any flight control element broke off, all sorts of bad things can happen. The age and maintenance of the aircraft matters too - especially the cycle-count for pressurized aircraft (how many times the aircraft becomes pressurized) and being extensively used in corrosive environments. I think the short hop flights between Hawaiian islands is one of the worse airframe environment for longevity. Remember the B73 that blew out the top quarter of the fuselage and landed with passengers enjoying the sun-roof view? https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243

Intuitively, I'd guess - just a guess - that once an jetliner is beyond vertical headed towards the ground, then the pilot would need to roll the aircraft into a typical "up" and pull back. Huge negative Gs aren't really something that airliners are designed to handle, at least not as much as normal (positive) Gs. Certified pilots will memorize these things and have practiced them both in real aircraft (smaller trainers) and in 6-d-o-f simulators for the aircraft they are being certified to operate. I'd guess about 2.5Gs is the positive suggested limit and -1G is the negative. The aircraft can handle much more.

During an actual emergency, pilots have to check lots of inputs, figure out what is likely, work through procedures, and perhaps move onto the next likely issue if the last one was incorrect. All while aimed at the ground and perhaps spinning/rolling.

The physics engines for current flight simulation software are pretty good. You can get/download one of those, hop into a B738 and try to reproduce the incident. Some simulator options:

FlightGear

X-Plane

YS Flight Simulator

0 ( +0 / -0 )

So, a few clarifications.

Black boxes are still used in the days where aircraft engines maintain satellite telemetry links to the manufacturer because they still provide the most detailed and reliable records.

Although the cockpit voice data recorder is inevitably located in close proximity to the cockpit, the engine data recorder is not, in part because by separating the two recorders, odds of them both being destroyed or disabled drop significant.

And airplanes who's flight controls are in the pitch down positions that aren't specifically designed to perform extreme aerobatics or being flown by very experienced pilots in a controlled fashion don't loop, because once they pitch down enough, they pick up enough speed to disrupt the aerodynamics.

0 ( +1 / -1 )

Can someone who is either a pilot or understands flight controls answer a question for me please:

Unless something breaks, for the aircraft to go into a steep dive means that the control stick has to be pushed fully forward, either by the flight crew or the autopilot, forcing the elevators fully down and the tail to go up. Once the aircraft has reached the vertical position and the elevators are still fully down, does the aircraft stay in a vertical dive or does it loop back under itself. What I mean is, once vertical, in order to stay that way does the stick have to be pulled back in order to maintain the vertical dive?

TIA.

-1 ( +1 / -2 )

If the engines and other parts of the aircraft can communicate with their manufacturers in real time, why not collect all the information that way?

What if that link goes non operational due to whatever brings the plane down?

Having onboard recordings of two sources, flight data and voice recorder, records info till the final moment of all flights. A comms link could stop minutes before the final moment, losing much information. Or are you recommending duplication of thousands of aircraft flight information? recording them and storage would be another huge cost for passengers to cover with ticket prices.

The current system works. If it is not broken....

3 ( +3 / -0 )

The way the plane dropped out of the sky but still in one piece (not blown up by a bomb etc) is most like the silk air crash which was eventually deemed to be a pilot suicide. Wonder if that was the case here too.

-1 ( +2 / -3 )

The plane was equipped with two flight recorders: one in the rear passenger cabin tracking flight data, and the other a cockpit voice recorder.

Poorly written. Planes have two flight recorders that are both located in the rear of the aircraft. One records flight data parameters and the other records everything said in the cockpit.

4 ( +4 / -0 )

Diligent efforts by those searching to find a second, yet major of the puzzle. May the families of those lost souls find some solace in this thorough and, so far, transparent investigation that’s being pursued.

4 ( +5 / -1 )

Why do they still use black boxes in this day and age? If the engines and other parts of the aircraft can communicate with their manufacturers in real time, why not collect all the information that way?

-7 ( +1 / -8 )

Under ICAO regulations the nation that built the mishap aircraft is supposed to lead the mishap investigation.

That's not my understanding. I thought it was generally the nation/state where the accident occurred (State of Occurrence) that has prime responsibility for conducting the investigation.

http://www.emsa.europa.eu/retro/Docs/marine_casualties/annex_13.pdf

2 ( +4 / -2 )

I have a sneaky suspicion that what will be reported by the Chinese authorities will be something along the lines of 'the sole cause of this tragedy was poorly made American aircraft.'

-5 ( +3 / -8 )

Good news. People who lost loved ones deserve answers.

The Chinese have not yet allowed investigators from the NTSB and Boeing to enter China. Under ICAO regulations the nation that built the mishap aircraft is supposed to lead the mishap investigation. There is a fear the Chinese may have already downloaded information from the first black box with the voice recordings and the US investigators if they ever arrive will never be sure they have all the information before them.

4 ( +8 / -4 )

Good news. People who lost loved ones deserve answers.

5 ( +8 / -3 )

I hope it wasn't made in China.

-12 ( +3 / -15 )

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