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smartplane
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 7:44 pm

So many posts on here now, but....

Did I imagine that the stick force pushing forward increases every time a 6 second burst occurs?

Could the break in pulling back as per FDR, be because a crew member had to exert so much physical force, one of them had to get out of their seat to push rather than pull?

Were the crew forces exerted so physically great, that mechanical damage / failure occurred shortly before impact?
 
airnorth
Posts: 469
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 8:02 pm

MSPNWA wrote:
litz wrote:
Some of these shallow water impact craters are amazingly deep, go look at the writeups on the recovery of the Valujet everglades crash ... pieces of that airplane ended up way, way underneath the bottom of the swamp (after going through several feet of water). High speeds will do that. Front end pushes the water out of the way, back end augers into the soft ground and just keeps going. Then the water rushes back in and covers everything up.


There's a fundamental difference between splashing into a shallow swamp and hitting an ocean 100 feet deep. You can get an idea of this at home. Throw a half-empty beverage can down into a puddle. Then throw it into a large bucket of water.

Physics tells us the plane would disintegrate on impact and cause minor, if any, displacement of the ocean floor. And the initial video of the wreckage (assuming authenticity of the video of course) confirms the science behind it. 28 feet is not plausible due to the impact alone. Even the most violent surface impacts are only about this deep or less.There needs to be an explanation given to us of how it was 28 feet below the water.

What are the differences and the physics involved in both of those scenarios you describe?
 
Boeingphan
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 8:18 pm

MSPNWA is spot on with the physics involved. I realize you can sift through mud/silt but the reality is 28' is significant. To think they dug 3 stories down in one location and "found" the CVR is remarkable. I live in a walk out 2 story house and to think from my upper floor ceiling to the basement walk out is roughly 30'. That's really mind blowing that they had the wherewithal to dig right there for a small piece. I'm not claiming any conspiracy theory I just think there its utterly amazing luck.
 
fadecfault
Posts: 164
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 8:30 pm

StTim wrote:
But this wasn't a runaway trim in the way that the pilots are trained for. For that the trim switches are ineffective. Here the trim actions were intermittent and stopped by trim adjustments. So it wasn't the trained for runaway trim.


Cite your source stating just because trim switches stop the movement of stab trim it is not runaway trim situation.
An actual Boeing flight ops manual.
 
fsabo
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 8:38 pm

Boeingphan wrote:
MSPNWA is spot on with the physics involved. I realize you can sift through mud/silt but the reality is 28' is significant. To think they dug 3 stories down in one location and "found" the CVR is remarkable. I live in a walk out 2 story house and to think from my upper floor ceiling to the basement walk out is roughly 30'. That's really mind blowing that they had the wherewithal to dig right there for a small piece. I'm not claiming any conspiracy theory I just think there its utterly amazing luck.


I would take those 8m with a large grain of salt. Digging in a murky underwater environment is hardly like digging an 8m deep hole on solid dry gound and finding an object at the bottom. Howver deep a hole they managed to dig, the CVR probably rolled down to the bottom of it in extremely murky conditions.
 
fadecfault
Posts: 164
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 8:38 pm

smartplane wrote:
So many posts on here now, but....

Did I imagine that the stick force pushing forward increases every time a 6 second burst occurs?

Could the break in pulling back as per FDR, be because a crew member had to exert so much physical force, one of them had to get out of their seat to push rather than pull?

Were the crew forces exerted so physically great, that mechanical damage / failure occurred shortly before impact?


It is not a stick pusher design and does not push forward. It will resist pulling backwards but it's not clear exactly how much force.
The FDR data from the 3 elevator position sensors need to be seen to really figure out what happened.
 
iamlucky13
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 9:18 pm

MSPNWA wrote:
litz wrote:
Some of these shallow water impact craters are amazingly deep, go look at the writeups on the recovery of the Valujet everglades crash ... pieces of that airplane ended up way, way underneath the bottom of the swamp (after going through several feet of water). High speeds will do that. Front end pushes the water out of the way, back end augers into the soft ground and just keeps going. Then the water rushes back in and covers everything up.


There's a fundamental difference between splashing into a shallow swamp and hitting an ocean 100 feet deep. You can get an idea of this at home. Throw a half-empty beverage can down into a puddle. Then throw it into a large bucket of water.

Physics tells us the plane would disintegrate on impact and cause minor, if any, displacement of the ocean floor. And the initial video of the wreckage (assuming authenticity of the video of course) confirms the science behind it. 28 feet is not plausible due to the impact alone. Even the most violent surface impacts are only about this deep or less.There needs to be an explanation given to us of how it was 28 feet below the water.


Any statement that begins "physics tells us" without recourse to any calculations or other evidence is dubious at the absolute best.

A wildly disproportionate comparison (a 0.15 kg object moving ~20 m/s vs. 75,000 kg object moving 200 m/s) doesn't help any. One event has 50 million times as much energy as the other. The propagation of the pressure pulse cited by litz is a real effect relevant to everything from how a depth charge can have a realistic chance of sinking a submarine to why your kitchen faucet could explode if you shut it off too fast if water hammer not been taken into account in its design.

That said, if you pour silt in the bottom of your bucket, I suspect you could actually replicate this in sub-scale. As a first approximation, make the depth above the silt about 3/4 the length of the beverage can (comparable to the actual water depth compared to the 737 Max 8 length), chuck it in there good and hard, and see if the sediment is disturbed. I didn't take the time to analyze the similitude, and this suggestion probably significantly under-emphasizes the importance of the velocity, but I suspect you'll still be able to throw it hard enough to kick up some sediment.

An additional test you could try is to stick a marble to the bottom of the can in a way such that it will dislodge on impact. See if it ends up buried in the silt.

For that matter, if you try a variety of different soil particle sizes and densities, you will find examples where an object of moderate density will sink into the sediment even if set gently on top of the sediment, no impact or initial velocity required.
 
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YSAPW
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 9:22 pm

On a relative different note: with today’s technology, specially cloud storage, how difficult would it be to create some sort of “video black box”. I wouldn’t exactly know the technical aspects of the item holding the physical memory “disk” (and wiring, an connections, etc.); but every couple of flights or so, the data would be automatically erasing itself – or being transferred to the cloud. That’s put in layman terms, but you get the idea. I know that if it has not been done yet, it is of course because of “X good reason”. But wouldn’t It also help a lot, in such scenarios, to actually see what was happening inside the cockpit?
 
MSPNWA
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 9:33 pm

iamlucky13 wrote:
Any statement that begins "physics tells us" without recourse to any calculations or other evidence is dubious at the absolute best.

A wildly disproportionate comparison (a 0.15 kg object moving ~20 m/s vs. 75,000 kg object moving 200 m/s) doesn't help any. One event has 50 million times as much energy as the other. The propagation of the pressure pulse cited by litz is a real effect relevant to everything from how a depth charge can have a realistic chance of sinking a submarine to why your kitchen faucet could explode if you shut it off too fast if water hammer not been taken into account in its design.

That said, if you pour silt in the bottom of your bucket, I suspect you could actually replicate this in sub-scale. As a first approximation, make the depth above the silt about 3/4 the length of the beverage can (comparable to the actual water depth compared to the 737 Max 8 length), chuck it in there good and hard, and see if the sediment is disturbed. I didn't take the time to analyze the similitude, and this suggestion probably significantly under-emphasizes the importance of the velocity, but I suspect you'll still be able to throw it hard enough to kick up some sediment.

An additional test you could try is to stick a marble to the bottom of the can in a way such that it will dislodge on impact. See if it ends up buried in the silt.

For that matter, if you try a variety of different soil particle sizes and densities, you will find examples where an object of moderate density will sink into the sediment even if set gently on top of the sediment, no impact or initial velocity required.


And any rebuttal that doesn't explain how another theory is more plausible is best ignored. If you're going to pick at details of an elementary example of how the ValuJet crash is not a good comparison, let's see some real science.

Please do. Replicate the crash. Explain to us how this crash had the energy required to push through 100 feet of water and create a crater at least 28 feet deep (a crater I know I never read about on the news).
 
marcelh
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 9:39 pm

MSPNWA wrote:
litz wrote:
Some of these shallow water impact craters are amazingly deep, go look at the writeups on the recovery of the Valujet everglades crash ... pieces of that airplane ended up way, way underneath the bottom of the swamp (after going through several feet of water). High speeds will do that. Front end pushes the water out of the way, back end augers into the soft ground and just keeps going. Then the water rushes back in and covers everything up.


There's a fundamental difference between splashing into a shallow swamp and hitting an ocean 100 feet deep. You can get an idea of this at home. Throw a half-empty beverage can down into a puddle. Then throw it into a large bucket of water.

Physics tells us the plane would disintegrate on impact and cause minor, if any, displacement of the ocean floor. And the initial video of the wreckage (assuming authenticity of the video of course) confirms the science behind it. 28 feet is not plausible due to the impact alone. Even the most violent surface impacts are only about this deep or less.There needs to be an explanation given to us of how it was 28 feet below the water.


Would you asked the same questions when it was a 737MAX operated by an US airline?
 
iamlucky13
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 10:22 pm

MSPNWA wrote:
And any rebuttal that doesn't explain how another theory is more plausible is best ignored. If you're going to pick at details of an elementary example of how the ValuJet crash is not a good comparison, let's see some real science.

Please do. Replicate the crash. Explain to us how this crash had the energy required to push through 100 feet of water and create a crater at least 28 feet deep (a crater I know I never read about on the news).


I offered you some real science you are (I presume) capable of performing yourself, as an extension of your own example.

Valujet is only useful as a rough example, but it does demonstrate the precedence for aircraft parts being buried deeply in soft sediment.

The scenario Litz posed did not include a permanent crater 28 feet deep. It suggested the pressure wave generated by the impact could temporarily displace soft enough sediment to such a depth, allowing any aircraft parts sinking into the displaced area to then be buried.

This is not the only plausible scenario. Applying even low forces to the right type of saturated soil can allow an object to sink into the soil with ease. Liquefaction is on the of the prime examples. Quicksand is a less common example.

While I am amused by your demand that I replicate the crash in order to gain your credulity, I decline to do so. Thanks for the laugh, however.

I offered some lesser demonstrations that could be attempted with little effort as alternatives. I already noted one of the major shortcomings of the examples. If I had enough time, I could quantity that shortcoming better, but at the present I do not have the time.
 
MaksFly
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 10:37 pm

I am always a fan of conspiracies but gees, FFS...

Fake CVR that was planted?

I suppose you never went diving? Or stood on the beach with your feet in the sand and saw how currents kept pushing more sand on top of your feet?

We are not talking about super deep water here. This was near the shore and you have lots of currents. Top it off this is a major shipping lane so every passing boat disturbs the area even more. Having it that covered with silt and sand after more than a month is completely plausible. Much more plausible than it was faked.

For crying out loud, if there was a cover up, it would be far easier to never find it in the first place, or have it immediately found in 1,000 pieces, on fire, and then have the UPS/Fedex truck crash and explode. lol.
 
dakota123
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 11:15 pm

Just spitballing, but the water following impact is going to have a lot of entrained air, and the CVR is following other debris so the surface tension would have been broken. I agree 8 m is a head scratcher, but doesn't seem completely implausible.
 
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SheikhDjibouti
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 11:19 pm

MSPNWA wrote:
Physics tells us the plane would disintegrate on impact and cause minor, if any, displacement of the ocean floor.
28 feet is not plausible due to the impact alone.
I agree you have raised valid points there.
MSPNWA wrote:
There needs to be an explanation given to us of how it was 28 feet below the water.
No, that's just you. I'm one of many people here who are perfectly happy.

iamlucky13 wrote:
For that matter, if you try a variety of different soil particle sizes and densities, you will find examples where an object of moderate density will sink into the sediment even if set gently on top of the sediment, no impact or initial velocity required.
Bingo, we have a winner! :checkmark: :hyper:
It really could be as simple as that.

It was only 7 days ago that smartplane came up with reason why diving in this area was problematic
smartplane wrote:
But this is a relatively fast flowing tidal body of water, in an area where they can't place anchors due to power and telecommunications cables on the seabed. Very few navies operate vessels capable of remaining on station without anchors.
Unwittingly, along with arguing for why the CVR might never be found, smartplane gave us the reason why it could be buried so deep (slowly sinking into a body of mud, constantly agitated by fast flowing tidal currents.).
And, best of all, we also have the means to reveal the CVR; use an airlift pump to quickly shift hundreds of tons of that mud up into the "fast flowing tidal waters", and watch all that mud simply disappear downstream.

Or, drop a heavily weighted diver right down into the mud, and let him stir up the mud with a broom handle until he hits something solid. Or if a broom handle isn't high tech enough, equip him with an underwater metal detector for less than $300.

There are so many easy solutions it's embarrassing.

I'm fairly certain I've said all this before, but for some reason there are people here who don't want to accept it.
 
airtechy
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Mon Jan 14, 2019 11:41 pm

If i recall, most of the wreckage of the Swissair MD11 that went down in Peggy's Cove was retrieved by dredging. Also, I'm not sure that the CVR was found at the bottom of the mud and silt. The article is not clear.

Having starting my 50 year flying career in a Cessna 150, I was not privileged enough to initially have electric trim...you had to use the "arm strong" method. That came in the 80's with a yoke mounted switch on a Cessna 310..a great help when lowering flaps! Also, along with the electric trim came a caution from my instructor that if it stuck on you could be in serious trouble ... and how to disable it. The 310 was at first a yoke switch driving a trim motor, but the autopilot (if turned on) had an input that could control climb and descent rate and hold altitude.

Now, obviously the engineers have found a new use for that trim motor...stall prevention and maybe other "improvements" that we don't know about. What we do know is that there is a lot of electronics whose calculations are summed into that motor ... electronics that can and does fail. If not the electronics then the sensors or all the cabling associated with it. For that reason, every plane I know of has a means to disable the motor itself, because identifying all the possible failure modes "upstream" is not practical. An intermittent short would probably give the same symptoms as the Lion Air flight.

That's why I find it interesting that there was "no procedure", because for all the possible failures that could cause a trim malfunction the procedure would end with the last statement being "disable the automatic trim with the cutout switches". And there are two switches in case one fails.

I'll leave it to the courts and lawyers to decide who is responsible for the accident, but clearly there was a means provided to stop a erratic/runaway trim and it seems clear from the FDR that these pilots failed to use that "means". Seems like it should almost be a "memory item".
 
salttee
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:00 am

airtechy wrote:
If i recall, most of the wreckage of the Swissair MD11 that went down in Peggy's Cove was retrieved by dredging. Also, I'm not sure that the CVR was found at the bottom of the mud and silt. The article is not clear.

Having starting my 50 year flying career in a Cessna 150, I was not privileged enough to initially have electric trim...you had to use the "arm strong" method. That came in the 80's with a yoke mounted switch on a Cessna 310..a great help when lowering flaps! Also, along with the electric trim came a caution from my instructor that if it stuck on you could be in serious trouble ... and how to disable it. The 310 was at first a yoke switch driving a trim motor, but the autopilot (if turned on) had an input that could control climb and descent rate and hold altitude.

Now, obviously the engineers have found a new use for that trim motor...stall prevention and maybe other "improvements" that we don't know about. What we do know is that there is a lot of electronics whose calculations are summed into that motor ... electronics that can and does fail. If not the electronics then the sensors or all the cabling associated with it. For that reason, every plane I know of has a means to disable the motor itself, because identifying all the possible failure modes "upstream" is not practical. An intermittent short would probably give the same symptoms as the Lion Air flight.

That's why I find it interesting that there was "no procedure", because for all the possible failures that could cause a trim malfunction the procedure would end with the last statement being "disable the automatic trim with the cutout switches". And there are two switches in case one fails.

I'll leave it to the courts and lawyers to decide who is responsible for the accident, but clearly there was a means provided to stop a erratic/runaway trim and it seems clear from the FDR that these pilots failed to use that "means". Seems like it should almost be a "memory item".

Very well said.
Thank you.
 
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PixelFlight
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:07 am

United787 wrote:
Here is what I don't understand. I know when there is a high impact crash into terrain, debris can be buried deep in the ground (e.g. AA 4184). But, when a plane hits the water, I would think that the initial impact with the water would break up the plane into thousands of smaller pieces and then those smaller pieces would slow considerably having travelled through 30 meters of water before hitting the ocean floor...

The fact that an aircraft is aerodynamic, with a relative small section compared to his length, probably explain how it penetrate 30 meter of water with still enough energy to dig into 8 meter of mud.

A possible scenario is that the forward cone will implode on contact with the water surface and make a sharper shape that push the water away of the fuselage. Once that the surrounding water has accelerate away, the rest of the fuselage mass will loss far less energy going down by the same path.

A very naive and highly approximate approach, without any verification (this can be completely wrong):
The energy of the about 40 tonne aircraft at the speed of 205 m/s (400 knots according to post #489) = 1/2 * 40e3 * 205**2 = ~840 MJ. Let's assume a 4 m diameter (roughly a 737 fuselage) 30 m height cylinder of water of 1000 kg/m3, this is about Pi * 4 * 30 * 1000 = ~377 tonne of water to displace. If the imploding fuselage end up in a ideal shape of a 40 m long cone with a 4 m base diameter, then the required displacement of the water going away from the axis of the cylinder will be only 2 m while the fuselage travel 40 m into the water = 1/20 ratio (even if it hit the floor after 30 m). So the speed of the water will be 205/20 = ~10 m/s. The energy to displace 377 tonne of water to 10 m/s = 1/2 * 377e3 * 10**2 = ~19MJ. Compare this to the ~840MJ, this is only about less than 3% of the total energy of the aircraft. Of course a real estimation will not be that easy and the % of energy loss into the water will be much higher, but the margin is high too.

On the other hand, if the front of the aircraft disintegrate on the water surface impact, then the water will fill the cabin, requiring a far less water displacement.
 
sealevel
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:51 am

Seeing that Flightglobal reporting the CVR has been recovered....
 
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FlyXLsa
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:51 am

SheikhDjibouti wrote:
Or, drop a heavily weighted diver right down into the mud, and let him stir up the mud with a broom handle until he hits something solid. Or if a broom handle isn't high tech enough, equip him with an underwater metal detector for less than $300.

There are so many easy solutions it's embarrassing.

I'm fairly certain I've said all this before, but for some reason there are people here who don't want to accept it.


There's nothing "EASY" about diving a debris filled, low viz, muddy bottom open ocean with significant currents.
There's one dead "EXPERIENCED" Indonesian diver from the first search to prove this.
Further, your prescribed search method above clearly shows you have no clue what you are talking about.
 
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SheikhDjibouti
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 1:04 am

FlyXLsa wrote:
SheikhDjibouti wrote:
Or, drop a heavily weighted diver right down into the mud, and let him stir up the mud with a broom handle until he hits something solid. Or if a broom handle isn't high tech enough, equip him with an underwater metal detector for less than $300.

There are so many easy solutions it's embarrassing.


There's nothing "EASY" about diving a debris filled, low viz, muddy bottom open ocean with significant currents.
There's one dead "EXPERIENCED" Indonesian diver from the first search to prove this.
Further, your prescribed search method above clearly shows you have no clue what you are talking about.

I've got to hand it to you, your comprehensive & detailed explanation has blown my ideas right out of the water.... :rotfl: .
Thank goodness you turned up and explained it all so beautifully.
 
SimpleFlying
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 1:53 am

This is a news in Indonesian correcting the statement about 28 feet under the mud. The CVR is only 20 cm under the mud. (It is 20 cm under the mud. The mud top is 30 m below the surface of the sea)

https://m.kumparan.com/@kumparannews/tni-al-siapkan-penghargaan-untuk-4-penyelam-penemu-cvr-lion-air-jt-610-1547457767331330871?utm_source=msnid&utm_medium=Aggregator

Below is the paragraph stating the correction (Indonesian):

"'Tadi ternyata ada koreksi, dari awal yang 8 meter dibawah lumpur tadi, ternyata hanya 20 cm. Jadi 20 cm di bawah lumpur,' ucapnya."

And below is the Google Translate:

"'It turned out that there was a correction, from the beginning 8 meters below the mud, it turned out to be only 20 cm. So it was 20 cm below the mud,' he said."
 
sgrow787
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:19 am

fadecfault wrote:
It is not a stick pusher design and does not push forward. It will resist pulling backwards but it's not clear exactly how much force.
The FDR data from the 3 elevator position sensors need to be seen to really figure out what happened.


Peter Lemme posted FDR data/graph showing column force data between 0 and 50 lbs for a few minutes, then the last 15 seconds 75-100 lbs:

https://www.satcom.guru/2018/11/first-look-at-jt610-flight-data.html
 
N212R
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:20 am

The Keystone Kops could have written a more convincing script.
Last edited by N212R on Tue Jan 15, 2019 2:22 am, edited 1 time in total.
 
salttee
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:21 am

SheikhDjibouti wrote:
FlyXLsa wrote:
SheikhDjibouti wrote:
Or, drop a heavily weighted diver right down into the mud, and let him stir up the mud with a broom handle until he hits something solid. Or if a broom handle isn't high tech enough, equip him with an underwater metal detector for less than $300.

There are so many easy solutions it's embarrassing.


There's nothing "EASY" about diving a debris filled, low viz, muddy bottom open ocean with significant currents.
There's one dead "EXPERIENCED" Indonesian diver from the first search to prove this.
Further, your prescribed search method above clearly shows you have no clue what you are talking about.

I've got to hand it to you, your comprehensive & detailed explanation has blown my ideas right out of the water.... :rotfl: .
Thank goodness you turned up and explained it all so beautifully.
It's obvious that you're not a diver and so it is true that you "have no clue what you are talking about." Why do you even bother to argue the point? Do you really think FlyXLsa is obligated to give you a dissertation on what it's like to dive at 90 feet in poor (or no) visibility with current? I know that you don't know it, but 90 feet is a deep aka dangerous dive in all but the very best conditions. So factor that into your armchair calculations.
 
sgrow787
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:27 am

SimpleFlying wrote:
This is a news in Indonesian correcting the statement about 28 feet under the mud. The CVR is only 20 cm under the mud. (It is 20 cm under the mud. The mud top is 30 m below the surface of the sea)


I'm not surprised. Growing up around creeks and rivers, jumping or swinging into from 30 ft is enough to make one realize just how hard water can be when hit with any kind of velocity.

So yes, 28cm came to mind on my way to work this morning. That's about a foot. 20cm is 8 inches. That's good enough for me..
 
PlanesNTrains
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:27 am

N212R wrote:
The Keystone Kops could have written a more convincing script.


I can’t remember but did you predict that they would not find the CVR? Now that they found it, what are you predicting the outcome will be? I know you’re convinced that something nefarious is going on so I just would like to get your ultimate prediction now.
 
N212R
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:35 am

PlanesNTrains wrote:
I can’t remember but did you predict that they would not find the CVR? Now that they found it, what are you predicting the outcome will be? I know you’re convinced that something nefarious is going on so I just would like to get your ultimate prediction now.


The data will be found to be non-exploitable.

Thank you for asking.
 
PlanesNTrains
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:51 am

N212R wrote:
PlanesNTrains wrote:
I can’t remember but did you predict that they would not find the CVR? Now that they found it, what are you predicting the outcome will be? I know you’re convinced that something nefarious is going on so I just would like to get your ultimate prediction now.


The data will be found to be non-exploitable.

Thank you for asking.


Thanks for the honest reply.
 
Flaps
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 3:53 am

litz wrote:
this:

trav777 wrote:
These were Lion Air "pilots". "Flying" a jet that should have returned to base on the previous leg. This plane should not have been in the air at all. Nothing is wrong with MCAS, the lack of redundancy in the AoA sensor chain is the defect here.

But, reading the reports of pilot activity...I'm sorry. I've flown. If the plane is going haywire and you do something and it goes straight and level, YOU DON'T TOUCH A THING AFTER THAT and you return to the runway. I cannot even fathom a professional pilot in a jet that is trying to push you into the ground and you go flaps 1 and it levels out and you....disengage flaps!??!? Then it tries to kill you again and you go flaps1 and it stops and you....AGAIN disengage flaps? This is insane.


I just can't fathom the logic that lead to this. Maybe we'll find out from the CVR now.


AS 261....Not an apples to apples comparison but the AS crew although gaining a reasonable semblance of control several times, kept on fiddling with the stabilizer until they broke it and ended up on their backs. I've always wondered if that outcome would have been different if they had just stopped messing with it once they had gained a reasonable measure of control. That was a very similar instance to this one with regard to the flaps.
 
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caoimhin
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 5:02 am

I had been looking forward to this thread all day. I want to commend everyone for their civil, grounded, and productive dialogue.
 
salttee
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 5:05 am

caoimhin wrote:
I had been looking forward to this thread all day. I want to commend everyone for their civil, grounded, and productive dialogue.

This is the lull before the storm.

If the storm ever really comes. We are holding our breath waiting on the contents of the CVR. Other than that there really isn't much to be said about the sad story of JT610. Unless you have something to add.
 
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qf789
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 5:49 am

Please stay on topic, what a particular poster said about MH370 sometime ago is irrelevant and please keep it civil
 
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caoimhin
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 6:45 am

salttee wrote:
caoimhin wrote:
I had been looking forward to this thread all day. I want to commend everyone for their civil, grounded, and productive dialogue.

This is the lull before the storm.

If the storm ever really comes. We are holding our breath waiting on the contents of the CVR. Other than that there really isn't much to be said about the sad story of JT610. Unless you have something to add.


Mate you’re doing everything but hold your breath waiting on the CVR contents. And, frankly, I don’t know that I disagree with you. But my man, let’s be clear that there are, at this point, competing theories that have equal merit to your own.
 
dynamo12
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 6:49 am

airtechy wrote:
If i recall, most of the wreckage of the Swissair MD11 that went down in Peggy's Cove was retrieved by dredging. Also, I'm not sure that the CVR was found at the bottom of the mud and silt. The article is not clear.

Having starting my 50 year flying career in a Cessna 150, I was not privileged enough to initially have electric trim...you had to use the "arm strong" method. That came in the 80's with a yoke mounted switch on a Cessna 310..a great help when lowering flaps! Also, along with the electric trim came a caution from my instructor that if it stuck on you could be in serious trouble ... and how to disable it. The 310 was at first a yoke switch driving a trim motor, but the autopilot (if turned on) had an input that could control climb and descent rate and hold altitude.

Now, obviously the engineers have found a new use for that trim motor...stall prevention and maybe other "improvements" that we don't know about. What we do know is that there is a lot of electronics whose calculations are summed into that motor ... electronics that can and does fail. If not the electronics then the sensors or all the cabling associated with it. For that reason, every plane I know of has a means to disable the motor itself, because identifying all the possible failure modes "upstream" is not practical. An intermittent short would probably give the same symptoms as the Lion Air flight.

That's why I find it interesting that there was "no procedure", because for all the possible failures that could cause a trim malfunction the procedure would end with the last statement being "disable the automatic trim with the cutout switches". And there are two switches in case one fails.

I'll leave it to the courts and lawyers to decide who is responsible for the accident, but clearly there was a means provided to stop a erratic/runaway trim and it seems clear from the FDR that these pilots failed to use that "means". Seems like it should almost be a "memory item".


I couldn't have said it better. A memory item for issues which may result in severe damage to the aircraft if not addressed promptly. And of course this was already a memory item.
 
salttee
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 7:16 am

caoimhin wrote:
salttee wrote:
caoimhin wrote:
I had been looking forward to this thread all day. I want to commend everyone for their civil, grounded, and productive dialogue.

This is the lull before the storm.

If the storm ever really comes. We are holding our breath waiting on the contents of the CVR. Other than that there really isn't much to be said about the sad story of JT610. Unless you have something to add.


Mate you’re doing everything but hold your breath waiting on the CVR contents. And, frankly, I don’t know that I disagree with you. But my man, let’s be clear that there are, at this point, competing theories that have equal merit to your own.

Well yes, but that circular argument has gone around in the same circle too many times already. In fact, the only reason I returned to the discussion a week ago was that the people who hold a similar view to mine had tired of the constant reiteration of the other view so there was a vacancy so to speak.

I became very involved with the MH-370 story, and learned more than I ever wanted to know about Malaysian and Indonesian politics and ethics. In some ways this is deja vu all over again. Some of the same people even.
 
Noshow
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 7:46 am

There is no point in opening a wide conspiracy theory right now. They searched and they found it. That's good news and now we need to find out what happened to prevent it from happening again.
 
SimpleFlying
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 9:20 am

Based on my experience with Indonesia, it is true that you can't discount cover-up / conspiracies. But also based on my experience with Indonesia, this JT610 issue in my opinion is not big enough for Indonesian political/corporate establishment to put the effort in staging a cover up.

In other words, I don't see any big enough reason for a cover-up.
 
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SomebodyInTLS
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 10:25 am

SimpleFlying wrote:
This is a news in Indonesian correcting the statement about 28 feet under the mud. The CVR is only 20 cm under the mud.


That sounds like someone mistook 8in for 8m
 
fadecfault
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 10:51 am

sgrow787 wrote:
fadecfault wrote:
It is not a stick pusher design and does not push forward. It will resist pulling backwards but it's not clear exactly how much force.
The FDR data from the 3 elevator position sensors need to be seen to really figure out what happened.


Peter Lemme posted FDR data/graph showing column force data between 0 and 50 lbs for a few minutes, then the last 15 seconds 75-100 lbs:

https://www.satcom.guru/2018/11/first-look-at-jt610-flight-data.html


The FDR data shows how much force the f/o and ca pulled on the control column. It does not show how much restrictive force the EFS placed on the controls and it does not show the elevator position.
 
EChid
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:18 pm

trav777 wrote:
Fatal flight repeatedly got to straight and level and did not return

You lose legitimacy in my mind everytime you posit that they had no intention of returning and should have returned, and that that's what American pilots would have done etc. etc.

They had clearly stated their intention to return to the airport, but were trying to stabilize the plane before they could safely start negotiating a turn back to the airport. They never got it sufficiently stabilized for any length of time, certainly not long enough to feel confident that turning the plane was feasible. These facts are well known, and have been for some time.
 
EChid
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 12:26 pm

MaksFly wrote:
I am always a fan of conspiracies but gees, FFS...

Fake CVR that was planted?

For crying out loud, if there was a cover up, it would be far easier to never find it in the first place, or have it immediately found in 1,000 pieces, on fire, and then have the UPS/Fedex truck crash and explode. lol.

If you're referring to my post, I was joking. It was a prod at our little band of conspiracy theorists.

That said, I think a few of them have taken the idea and run with it...
 
Boeingphan
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 1:10 pm

And I stand correct when I critiqued the depths at which it was found. 28' of mud is unrealistic and for anyone to think they'd have stirred 28' of mud over a km of area is crazy.
 
Redd
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:05 pm

salttee wrote:
SheikhDjibouti wrote:
FlyXLsa wrote:

There's nothing "EASY" about diving a debris filled, low viz, muddy bottom open ocean with significant currents.
There's one dead "EXPERIENCED" Indonesian diver from the first search to prove this.
Further, your prescribed search method above clearly shows you have no clue what you are talking about.

I've got to hand it to you, your comprehensive & detailed explanation has blown my ideas right out of the water.... :rotfl: .
Thank goodness you turned up and explained it all so beautifully.
It's obvious that you're not a diver and so it is true that you "have no clue what you are talking about." Why do you even bother to argue the point? Do you really think FlyXLsa is obligated to give you a dissertation on what it's like to dive at 90 feet in poor (or no) visibility with current? I know that you don't know it, but 90 feet is a deep aka dangerous dive in all but the very best conditions. So factor that into your armchair calculations.


Agree with saltee & FlyXLsa. The idea of being lowered down into the mud 90 feet under water with a broom handle to sift through mud is completely and utterly absurd and shows a complete lack of understanding of diving.
 
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FlyXLsa
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:06 pm

Much respect for the Indonesian dive team that lost a "buddy" earlier in the search. I've been diving for fossilized shark teeth where a muddy river bottom met the ocean and can assure you stirring up that mud destroys visibility very quickly. Diving among metal debris is dangerous for obvious reasons. That they succeeded where the MPV Everest failed with superior technology makes this a good day for the Indonesian Navy.
 
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SheikhDjibouti
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:28 pm

FlyXLsa wrote:
There's nothing "EASY" about diving a debris filled, low viz, muddy bottom open ocean with significant currents.
There's one dead "EXPERIENCED" Indonesian diver from the first search to prove this.
Further, your prescribed search method above clearly shows you have no clue what you are talking about.

SheikhDjibouti wrote:
I've got to hand it to you, your comprehensive & detailed explanation has blown my ideas right out of the water.... :rotfl:

salttee wrote:
It's obvious that you're not a diver and so it is true that you "have no clue what you are talking about." Why do you even bother to argue the point? Do you really think FlyXLsa is obligated to give you a dissertation on what it's like to dive at 90 feet in poor (or no) visibility with current? I know that you don't know it, but 90 feet is a deep aka dangerous dive in all but the very best conditions. So factor that into your armchair calculations.

Ok, I'm going to break with a.net tradition and admit I am wrong.

I should have said;
"There are so many easy solutions, excluding any comments I made about diving"
(Note; that still leaves plenty of options, excluding Boeingplan's made up assumption that the mud would have to be cleared "over a km of area"; KRI reported their search area was confined to just 5 x 5m, which is somewhat less)

Meanwhile, it's good to have not just one, but two diving experts on board, neither of whom has identified their own qualifications, whilst both of whom are absolutely sure they know mine.

But given the dire warnings from you both, it's a wonder that the sport of recreational diving is so prevalent. I'll have to ask my brother-in-law about that; he's an instructor.

Under most entry-level programs (SEI, SDI, PADI, BSAC, SSAC, NAUI, SSI, and PDIC), divers can complete a certification with as few as four open water dives. This complies with the minimum requirements of ISO 24801-2 Autonomous diver. Such a qualification allows divers to rent equipment, receive air fills, and dive without supervision to depths typically restricted to 18 meters (60 feet) with an equally qualified buddy in conditions similar to, or easier than those in which they were trained.

I totally accept that diving in poor visibility and with current is beyond the capabilities of mere students, but despite your professed diving knowledge, you have grossly over stated the risk of diving to 90 feet.
Both NOAA & PADI recognise 130feet as a reasonable limit for recreational (amateur) diving.
PADI defines technical diving as "diving other than conventional commercial or recreational diving that takes divers beyond recreational diving limits (130 feet/40m)
Of course it has a risk; and so does flying an aircraft.

So, 90 feet is well within the range of weekend divers with limited experience. But I wasn't expecting amateur divers on this gig - that would have been stupid, and you would have been well within your rights to call me out on that.

As for limited visibilty; this is a bigger issue, and obviously takes things beyond the realms of normal sport diving.
Wikipedia wrote:
Technical dives in waters where the diver's vision is severely impeded by low-visibility conditions, caused by turbidity or silt out and low light conditions due to depth or enclosure, require greater competence. The combination of low visibility and strong current can make dives in these conditions extremely hazardous, particularly in an overhead environment, and greater skill and reliable and familiar equipment are needed to manage this risk.
That all seems quite straightforward to me, and not necessarily worth such the song and dance you make of it. Just proper training and equipment and acknowledgement of the risks.

When I said there were "easy" solutions, it's a bit like telling someone there are easy solutions if you want to get from New York to Dublin.
You can swim, paddle a canoe, take a berth on a slightly larger vessel, or you might find it best to book a flight on one of the many aircraft that ply this route every day. The solution is easy. Flying the aircraft itself isn't necessarily "easy" , but that is not what I'm saying.

Can you see where you've both gone wrong now? (apart from the small matter of rudeness and resorting to personal attacks)

You make a big deal of telling me I don't know what I am talking about.
Have you ever been top-man for a diver repairing equipment at the bottom of a sewage tank?
It was a long time ago, and the tank was nowhere near 90' deep. But it did feature 8 meters of …. shall we call it "mud" ?
Image


Footnote; whilst writing this, I see FlyXLsa has belatedly confirmed his qualifications to talk on this matter (shallow depth sport diving).
That's good to know and I respect that.
 
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FlyXLsa
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 2:41 pm

Apologies if I was rude. Not my intent. Respect for your updated position.
 
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neutrino
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 3:13 pm

FlyXLsa wrote:
Much respect for the Indonesian dive team that lost a "buddy" earlier in the search. I've been diving for fossilized shark teeth where a muddy river bottom met the ocean and can assure you stirring up that mud destroys visibility very quickly. Diving among metal debris is dangerous for obvious reasons. That they succeeded where the MPV Everest failed with superior technology makes this a good day for the Indonesian Navy.

Not to take anything away from the Indo Navy divers but were they pinpointed the relatively tiny 5x5M area by the MPV Everest?
If so, all involved in the whole search & recovery efforts deserved the credit. In football terms, the striker hit the winning goal but their goalie, defenders, midfielders and the coach staff make the team. They are all heroes; striker and everyone else.
 
jetmatt777
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 4:15 pm

EChid wrote:
trav777 wrote:
Fatal flight repeatedly got to straight and level and did not return

You lose legitimacy in my mind everytime you posit that they had no intention of returning and should have returned, and that that's what American pilots would have done etc. etc.

They had clearly stated their intention to return to the airport, but were trying to stabilize the plane before they could safely start negotiating a turn back to the airport. They never got it sufficiently stabilized for any length of time, certainly not long enough to feel confident that turning the plane was feasible. These facts are well known, and have been for some time.


Exactly! Aviate. Navigate. Communicate. Keep the damn thing in the air before you start turning. I feel terrible for the crew who the cards were stacked against them. It’s easy to say from the ground what should have been done differently. Let’s let the investigation conclude before we all hang the pilots. They’ve died once already, let’s see what the experts have to say.
 
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FlyXLsa
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 4:19 pm

I saw a picture of the CVR on twitter with the Pinger sitting next to it so I'm not sure if the Everest Crew was instrumental in narrowing the search area or not? I didn't mean to downplay their contribution to the search effort. It would be nice if Lion Air got SOMETHING for the $2.5+ Million they paid out!
 
StTim
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Jan 15, 2019 4:55 pm

Apparently the pinger was still issuing weak pings. May have helped when they got close.

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