Air India AI 171 Crash in Ahmedabad (5 Viewers)

[shiphone]

it seems you are quite young or too young?
no need for more discussion (from me) but for the final report...TBO, the fact seems to be very clear already.

 

[Bhartiya Sainik]

it seems you are quite young or too young?

I don't pass personal comments, slangs bcoz i'm IT engineer in 40s, also religious minded.
In my profile itself i've mentioned humbly 'low IQ', 'mid-aged' & profile pic is of iconic EMC2 Symmetrix VMAX storage, the best one at its time. 'Too young' people don't know this.
Now i wonder if this is someone's Eye problem or IQ problem or both.

no need for more discussion (from me) but for the final report...TBO, the fact seems to be very clear already.

You are still most welcome to discuss neutrally, politely, with publicly verifiable stuff, that's what brings gavity, credibility, trust.
Mary Schiavo exposed that out of all pilot blaming cases, 75-80% were tech issues.
+ Boeing whistle blowers.
I'm still considering all angles being a techie.

 

[Psacha123]

View: https://x.com/shivaroor/status/1946404273224348129?s=46

 

[Bhartiya Sainik]

View: https://x.com/CaptShaktiLumba/status/1944397999750406329

Theoretically, TCB can also have electronic/electrical issues.

This aspect i mentioned in my last post that there are layers -
- mechanical switch layer
- electronic circuit layer below
- connectors & wiring layer
- S/w layer

> EEC's TCMA function shut down engines (fuel valves) of ANA 787 just before landing. This doesn't move guarded fuel switch.
> Load-relief function can operate flaps. This doesn't move notched flaps lever.
> Electrical Management's Load shedding function can deprioritise & auto-shut some fuel pumps, hydraullic pumps, etc under certain conditions. IDK yet if this will turn hydraulic, AC-pack knobs, etc in overhead panel.

So apart from S/w layer glitch,
the electronic circuit, connector, wiring layers can also have glitch, or maintenance issues.

Earlier, there was STAB POS XDCR message for Stabillier Position Transducer, which was troubleshooted.
STAB trim switch is in control column & thumb operated,
but red color guarded toggle switch for STAB on-cutoff are beside the fuel switches.



So where exactly was the issue?
- Transducer
- wiring
- connector
- switch
- something in TCB box?
From the message it appears that the Transducer is faulty, but a bad connector or wiring on either end MIGHT also produce this error.
An Electronics &/or Electrical engineer can tell best.

What exactly was troubleshooted?
Was something replaced like Stab Transducer, connector, wiring, Stab trim switch, stab on-off switch beside the fuel switches?

These 2 switches of Stab & fuel clearly seen to be 2 units with fixing screws. But still, can there be a short circuit in TCB box in or around Stab on-off switch, which also affected the Fuel switches?

 

[Bhartiya Sainik]

@Interested
check this video at @3:56 just after T/o
Do you hear clicking sound? Do you think it is similar to Fuel switches? IDK what is it.


View: https://youtu.be/2wvPZG_0lOI?si=qS4Sj4QvY-kjfuc5&t=235

@Interested
Check this at @6:27 again just after T/o.


View: https://youtu.be/j7q6wAudDDI?si=nO1EM70tPutHh6St&t=386

the 'click' sound of above video is the 'gear-up switch LOCK RELEASE' ...you can see after this click one of the crew starts to touch the swith to retractable landing gear... this switch is always locked on the ground.

> After searching i found that the tiny black color LOCK OVRD button beside the gear handle is pushed to release the gear lock when in down position, but it is auto-released upon T/o. This means that this button is pressed only when gear cannot be pulled up due to the lock.
> This is very difficult to see in videos from which we see that the monitoring pilot doesn't operate this button.
> It is also difficult to see in videos if the FMC auto-pushes this button bcoz these buttons are basically electronic 'relays'.

> Additionally, It is also the AUTOBRAKE knob turning from RTO to OFF.
It is located just below gear lever handle.
But the CLICK sounds plural. I wonder if more knobs, switches are auto-moved like this.
What a technial coincidence with AI-171 where some people are expecting Fuel switch off clicks around this time. I don't expect the investigation team would get confused with this click, especially when FDR data has revealed everything by now.



I'll expect repliers to do more homework & be precise & most importantly be polite.

 

[hurrians]

https://www.hindustantimes.com/india-news/air-india-crash-probe-investigators-examining-signs-of-electric-tail-fire-before-fatal-air-india-crash-101752985918456.html

 

[Bhartiya Sainik]

https://www.hindustantimes.com/india-news/air-india-crash-probe-investigators-examining-signs-of-electric-tail-fire-before-fatal-air-india-crash-101752985918456.html

Hmm, i wonder what in tail can cause both engines pull back or shut down.

High resolution images are difficult to find.
The tail has APU, battery for APU & rear galleys.
Behind the galleys is a bulkhead which i think is fire-hardened if APU catches fire + fire bottle for APU.






Initially long back there were battery issues which are said to be solved.



But suppose if we think that in AI-171 if there was tail battery or APU fire, then how would this affect engines?
AFAIK, on T/o the APU is not used & in this case also it was off, activated after engines failed.

 

[hurrians]

https://aaib.gov.in/What's%20New%20Assets/Preliminary%20Report%20VT-ANB.pdf

 

[hurrians]

The question is why is aft recorder more damaged than forward recorder including thermal and crash damages as per preliminary report- data couldn't be downloaded from it by "conventional" means

 

[Bhartiya Sainik]

The question is why is aft recorder more damaged than forward recorder including thermal and crash damages as per preliminary report- data couldn't be downloaded from it by "conventional" means

Perhaps bcoz the tail hit the mess building 1st causing it to break & stop instantly, this impact might have mechanically damaged rear FDR.
Theoretically, thermal damage could be due to fire in battery, galley, APU related components.
Combustible materials may catch fire due to impact friction also. Some fuel might have got splashed back from broken wings & fuselage too.

Compared to this, the forward FDR suffered different kind of impact. The broken forward fuselage seem to have brushed off the residential buildings ahead &/or landedon ground.