737-8 max plane goes down (2018) - new not Max crash Indonesia

cptaidan88 said:
Lets just say Boeing will be very hopeful that no mechanical issues are found.
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The Chinese investigation authority will be just as keen for it not to be a pilot or maintenance issue, so a healthy tension should ensure an accurate conclusion to the investigation.
Looking at the flight log, it went from 29000 feet to zero in just 3 minutes which doesn't sound like pilot error. Much more likely it was a mechanical failure or the pilot did it deliberately.
https://www.flightradar24.com/data/flights/mu5735#2b367bc1
A normal rate of descent is 2000-3000 feet per minute. This was more like 10000 feet per minute which is even more than an emergency descent rate that would be used in the event of the loss of cabin pressure. That increased to nearly 20,000 feet per minute in the 20 seconds before impact. It suggests the pilot was not controlling the aircraft because even a controlled descent with both engines failed would be a much less steep descent than that.
 
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Vertical dive from 30,000 feet. Hellish few seconds.
 
The only thing that can really cause a nosedive like this is the horizontal stabiliser. There's not many things that can cause the stabiliser to go full nose-down... complete hydraulics failure (highly unlikely - although has happened in the past), software failure or deliberate input from the pilot.
 
There is a video purporting to be of the final few seconds. It is on the Independent's site. It certainly fits with the vertical dive theory.... Damn.

Quote from Flightradar; "The rate of altitude loss increased even more, but after 45 seconds there appears to be a reversal, with a sharp gain in altitude before the descent begins again. The data appears to stop 96 seconds after the descent commenced."
 
Nick_1985 said:
Flown over 100 times. Still squirt a little piss out at the slightest sign of turbulence. How anybody enjoys flying is beyond me.
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I know it's the safest form of travel but I was always terrified of turbulence, so I decided to stop flying and take a train/boat instead. More expensive and more time consuming but for me stress free.
 
Cheesy said:
The only thing that can really cause a nosedive like this is the horizontal stabiliser. There's not many things that can cause the stabiliser to go full nose-down... complete hydraulics failure (highly unlikely - although has happened in the past), software failure or deliberate input from the pilot.
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The 737NG is not a FBW aircraft so a software failure couldn't have caused this.
 
Does it matter that the 737NG is not technically FBW? It uses an FCC, and inputs and feedback are both modified and mediated by the computer(s, there are at least two) in accordance with the various pilot aid / safety mechanisms.

Speed Trim and Mach Trim possibly appear relevant.

www.satcom.guru

Stabilizer Trim

LionAir JT610 plunged into the sea from what may have been the result of runaway stabilizer trim. The details are not released, but the FA...
www.satcom.guru www.satcom.guru
 
Summerbuzz said:
Does it matter that the 737NG is not technically FBW? It uses an FCC, and inputs and feedback are both modified and mediated by the computer(s, there are at least two) in accordance with the various pilot aid / safety mechanisms.

Speed Trim and Mach Trim possibly appear relevant.

www.satcom.guru

Stabilizer Trim

LionAir JT610 plunged into the sea from what may have been the result of runaway stabilizer trim. The details are not released, but the FA...
www.satcom.guru www.satcom.guru
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You've posted a link to some 737 MAX information. The 737NG is very different.
 
west didsblue said:
You've posted a link to some 737 MAX information. The 737NG is very different.
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LNI610 was a MAX - but the technical details and discussion in the article relate heavily to the 737NG.
This discussion is purely commentary, is based on incomplete information, does not profess to be accurate because of unknown information or because of misunderstanding, and does not contain any information known to be specifically applicable to the 737 Max, nor to Lion Air JT610. In fact, there is nothing here that describes why the issue is limited to 737 Max. I welcome any comments or suggestions, corrections and criticism.

..............................




The information discussed is applicable in part to Boeing 707, Boeing 737 Classic (-300, -400, -500), and Boeing 737 Next Generation (NG) (-600, -700, -800, -900).
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Hence headings like,

Boeing 737NG Pitch Controls​

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Summerbuzz said:
LNI610 was a MAX - but the technical details and discussion in the article relate heavily to the 737NG.

Hence headings like,
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The FCC on the 737NG controls a relatively minor number of functions, all of which have back ups. Primary flight controls are 100% non-FBW. There is no way a FCC software fault could have caused this without a number of other factors being involved.
https://www.737ng.co.uk/B_NG-Flight_Controls.pdf
The primary function of the FCC is the autopilot and flight director which can be disconnected if there's a problem. It is also involved with Mach trim. A failure could not cause a pilot to lose control.
 
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west didsblue said:
The FCC on the 737NG controls a relatively minor number of functions, all of which have back ups. Primary flight controls are 100% non-FBW. There is no way a FCC software fault could have caused this without a number of other factors being involved.
https://www.737ng.co.uk/B_NG-Flight_Controls.pdf
The primary function of the FCC is the autopilot and flight director which can be disconnected if there's a problem. It is also involved with Mach trim. A failure could not cause a pilot to lose control.
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Runaway trim certainly is a relevant topic. Whilst there are several unrelated possible causes, I don't see how we are close to ruling out any part played by the FCC / Stall computers.
 
Summerbuzz said:
Runaway trim certainly is a relevant topic. Whilst there are several unrelated possible causes, I don't see how we are close to ruling out any part played by the FCC / Stall computers.
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I didn't say they weren't involved.
Someone else said this could have been caused by a software fault. A software fault on its own on the 737NG could not have caused this. A failure of the FCC could have been a contributory factor.
 
Didn't realise that bluemoon had so many qualified aircraft crash investigators , should have know better as it also has so many pandemic and military strategy experts
 
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