Air India AI 171 Crash in Ahmedabad (1 Viewer)

[Bhartiya Sainik]

Fair enough but we must keep an open mind . Not everything is a conspiracy and people have tried to ascertain sequence of events based on fact they know .
Pilot error/suicide is the most possible of the outcome but like you said if this is not the case then truth will be out in next 1 year and we will know entire truth .

I already linked the Wiki page of pilot suicides, but -
- technical procedure to shut down fuel/engines doesn't match with blunt, short 1 line CVR data reported &,
- we don't know data on medical & psychological aspects of pilots.

We need the full CVR audio, not just transcript & also FDR data.

In matters of technology i always suggest & request people to focus directly on technology rather than who says what.
Why some people are not ready to consider sensor &/or S/w glitch when already happened in past multiple times?
In general, on something outside our academic/professional domain, before expressing ourselves, we should take our time, do some homework & always communicate with a verifiable base.
Our approach & tone should be neutral, not concluding.
That way we are relaying facts.

 

[Brood Father]

I already linked the Wiki page of pilot suicides, but -
- technical procedure to shut down fuel/engines doesn't match with blunt, short 1 line CVR data reported &,
- we don't know data on medical & psychological aspects of pilots.

We need the full CVR audio, not just transcript & also FDR data.

In matters of technology i always suggest & request people to focus directly on technology rather than who says what.
Why some people are not ready to consider sensor &/or S/w glitch when already happened in past multiple times?
In general, on something outside our academic/professional domain, before expressing ourselves, we should take our time, do some homework & always communicate with a verifiable base.
Our approach & tone should be neutral, not concluding.
That way we are relaying facts.

Chances of Sensor glitch on both equipment happening at the same time and at that altitude before Auto pilot kicked in it's very astronomical low .
I hope you are appreciating where I am coming from. This is whole my perspective , if I have to bet on the reason I will place my bet on human error not sensor malfunction happening at both redundant system at the same time

 

[Bhartiya Sainik]

@SKC @haldilal @Vinash , other mods/admins,
it seems some posts have been lost.
Yesterday something was in draft buffer, today that also lost.
You guys said everything will be restored, no loss.

 

[Bhartiya Sainik]

Chances of Sensor glitch on both equipment happening at the same time and at that altitude before Auto pilot kicked in it's very astronomical low .
I hope you are appreciating where I am coming from. This is whole my perspective , if I have to bet on the reason I will place my bet on human error not sensor malfunction happening at both redundant system at the same time

Technology doesn't work on bet. 1 in bilion or trillion thing can happen in last, middle, 1st instance itself.

Crash due to sensor malfunction with every civil & military jet has happened, especially during T/o & landing.

When redundant sensors give multiple values, it confuses FMC, then which value is right? Lowest, highest, average, median, standard deviation, etc?

Static ports, pitot's tubes are HOLE based sensors, measure air pressue to derive velocity & altitude.
So these are like our nose & ears for example.
The kind of awareness our eyes give is not given by nose & ears. A deaf person can navigate better than blind person.
When some dirt, insect, etc gets into our nose, ears we immediately detect it due to nerves, hairs, But such analogous detection is not there in air data sensors AFAIK. The FCS S/w has to be made cognitive based on flight segment & ambient conditions recorded so far, to decide which sensor is likely to be reporting wrong value. So the design engineers must be doing this already, but still crashes have happened for every jet due to bad sensor data.

The MCAS issues happened due to relying on only 1 AoA sensor, bad MCAS S/w not in sync with flight segment, ambience & other sensors.
In 5gen fighters the AoA sensor is replaced with IMU (Inertial Measurement Unit)/Accelerometer, i guess redundant too. They still have static ports, probes for temperature & pressure.

In this AI-171 case during T/o we can see a lot of dust in CCTV footage,
may be it is normal ground effect created by wings & engine thrust & appears as illusion due to camera angle,
but anyways since beginning i considered the theory of sensor clogging creating multiple values, confusing FMC & EEC & either reducing RPM to sub-idle or shut down similar to TCMA incident of ANA flight (during landing).

 

[johny_baba]

In this AI-171 case during T/o we can see a lot of dust in CCTV footage,
may be it is normal ground effect created by wings & engine thrust & appears as illusion due to camera angle,

offtopic but as someone who's lived in ahmedabad,
it's helluwa dusty city like even mughal badshah Jehangir himself called it out as Gardabad (city of dust) and what not back 400 years ago

Mughal emperor Jehangir gave Ahmedabad the moniker ‘Gardabad’ | Ahmedabad News - Times of India

When Mughal emperor Jehangir first visited Ahmedabad in 1617, he was crestfallen. In the Mughal annals, Jehangir says he had heard good things of the

timesofindia.indiatimes.com

and fucker was indeed right about it, man
...even with windows closed dust and dander makes into your homes easily, and air feels quite dry

so i think that dust in air is just your everyday air and environment of the city and not something suspicious

 

[Miss Firing]

'Switch could be at the same point': Expert says electrical malfunction may have caused fuel switch cut off before AI plane crash

According to the expert, an electrical malfunction could also have resulted in the aircraft’s fuel switches being cut off soon after takeoff.

www.firstpost.com

'Switch could be at the same point': Expert says electrical malfunction may have caused fuel switch cut off before AI plane crash​

 

[Interested]

Technology doesn't work on bet. 1 in bilion or trillion thing can happen in last, middle, 1st instance itself.

Crash due to sensor malfunction with every civil & military jet has happened, especially during T/o & landing.

When redundant sensors give multiple values, it confuses FMC, then which value is right? Lowest, highest, average, median, standard deviation, etc?

Static ports, pitot's tubes are HOLE based sensors, measure air pressue to derive velocity & altitude.
So these are like our nose & ears for example.
The kind of awareness our eyes give is not given by nose & ears. A deaf person can navigate better than blind person.
When some dirt, insect, etc gets into our nose, ears we immediately detect it due to nerves, hairs, But such analogous detection is not there in air data sensors AFAIK. The FCS S/w has to be made cognitive based on flight segment & ambient conditions recorded so far, to decide which sensor is likely to be reporting wrong value. So the design engineers must be doing this already, but still crashes have happened for every jet due to bad sensor data.

The MCAS issues happened due to relying on only 1 AoA sensor, bad MCAS S/w not in sync with flight segment, ambience & other sensors.
In 5gen fighters the AoA sensor is replaced with IMU (Inertial Measurement Unit)/Accelerometer, i guess redundant too. They still have static ports, probes for temperature & pressure.

In this AI-171 case during T/o we can see a lot of dust in CCTV footage,
may be it is normal ground effect created by wings & engine thrust & appears as illusion due to camera angle,
but anyways since beginning i considered the theory of sensor clogging creating multiple values, confusing FMC & EEC & either reducing RPM to sub-idle or shut down similar to TCMA incident of ANA flight (during landing).

The fuel switches were most likely physically moved to the off position , one after the other . The sound of that physically happening (audible click noise as per design of the spring engaging) will be captured in the cockpit recorder and also something the copilot probably saw and heard which is why he asked 'why did he cut off '.

The high possibility is a murder suicide by the pilot who seems like a odd cuckoo with no relationships other than with his elderly parents one of who passed away few years back . In India there is terrible stigma of gettting health for mental issues so the fact that he never got any help is also pretty normal

 

[Bhartiya Sainik]

offtopic but as someone who's lived in ahmedabad,
it's helluwa dusty city like even mughal badshah Jehangir himself called it out as Gardabad (city of dust) and what not back 400 years ago

Mughal emperor Jehangir gave Ahmedabad the moniker ‘Gardabad’ | Ahmedabad News - Times of India

When Mughal emperor Jehangir first visited Ahmedabad in 1617, he was crestfallen. In the Mughal annals, Jehangir says he had heard good things of the

timesofindia.indiatimes.com

and fucker was indeed right about it, man
...even with windows closed dust and dander makes into your homes easily, and air feels quite dry

so i think that dust in air is just your everyday air and environment of the city and not something suspicious

Hmm, if we see CCTV footage of crash & plane-spotter videos of Ahmedabad airport then the spaces beside runway look grassy.
Bigger jets like B-777, A-330, etc can also be seen.
But they're also sweeping off similar amount of dust.
In desert areas there would be far more amount of dust.
The jets are tested in many weather conditions during design & prototyping.
Mechanisms like 'anti-ice' have been developed but IDK there is something like 'anti-dust'.
Hence by 'swiss cheese model' & 'Murphy's law' sometimes clogged sensors have caused accidents for every type of jet.

 

[Bhartiya Sainik]

The fuel switches were most likely physically moved to the off position , one after the other . The sound of that physically happening (audible click noise as per design of the spring engaging) will be captured in the cockpit recorder and also something the copilot probably saw and heard which is why he asked 'why did he cut off '.

The high possibility is a murder suicide by the pilot who seems like a odd cuckoo with no relationships other than with his elderly parents one of who passed away few years back . In India there is terrible stigma of gettting health for mental issues so the fact that he never got any help is also pretty normal

At least the sincere people globally are suspecting how a report got leaked before official release which is punishable offence & blunt, irresponsible behavior on part of TECHNICALLY UNQUALIFIED people including journalists, etc.

Now, a sincere investigation considers all angles.
Hence I've already mentioned list of past pilot suicides, S/w glitch, H/w malfunction, sabotage, maintenance issues, fuel contamination, etc, etc.
I mentioned 25 bulleted points of various types/aspects/angles in the suicide possibility post.
But it seems you didn't read carefully. And some people still seem to be hell-bent only on pilot error, suicide....Hmm!!! This show insincerity, lobbying type of intentions.

Audio reflects TONE, emotions, NOT A WRITING. We need full CVR audio.
Like i said, in every office, some people may not get along well due to personal incompatibility, not socializing beyond professional boundaries, but HR rules compell them to work together, so they strictly mind their job & in case of errors they can misunderstand/suspect eachother bluntly.

5 fingers are different, world is in grey shades, some people are active, extrovert, some are relatively passive, introvert which doesn't qualify for crime by default.

Criminal masterminds can be very talkitive, social,
as well as passive types.

A high-valued critical profession like Engineer, Doctor, Pilot, etc, especially if in 24x7 or shift environment are very demanding, challenging, need good health, good analytical skills, sincerity, continious study with changing things, time management, decision making skills, etc.
Hence such professions have lesser time for social life. We can see most doctors, engineers, etc very busy Mon-Fri & in wekend with house-chores, banking, maintenance, etc then whatever they wanna do in their personal life, none of anybodys business.

Mental instability leading to suicide/murder would definitely reflect in public.
But pilots who worked with Captain Sumeet Sabarwal said that he normal, stable person.

Hence to prove pilot error, suicide, the CVR audio, medical records, behavioral data is needed. Otherwise bluntly blaming someone guilty by default unless proven innocent is 'summary execution' in a democracy & equal crime. At least India has IPC 499, 500 for defamation.

 

[Bhartiya Sainik]

Since beginning many people like Mary Schiavo (Former IG, US DoTr), Dr. Vandana Singh, some domestic & foreign pilots, enthusiasts like me, etc have considered S/w glitch with certain functions of FMC/EEC, we should see how confusion can occur with electro-mechanical man-machine interfaces.

All switches, buttons, knobs in the A/c are some kind of electronic relays, so the electrical signals are converted by ADC (Analog to Digital Convertor) mechanism & sent to FMC & then formatted & sent to FDR.




Some of the switches, buttons, levers, knobs can be controlled back in motion by the computer/auto-pilot,
For example -
- thrust levers in auto-thrust mode.
- engine start knobs from START to NORM.
- stabilizer trim wheel (787 doesn't have).
- speed brake lever.

...except the ones guarded by notches, brackets, covers, etc. But the computer/auto-pilot can still SOFT operate the functions.
For example-
- load-relief function for flaps, but flaps lever won't move. There'll be messages, perhaps LED & aural alarm then pilot has to adjust flap lever.
- EEC's TCMA shutting down engine(fuel valves) if RPM red line crossed, overspeed occurs, ground idle RPM issues, etc. But fuel switch won't move. In case of mid-flight shutdown the pilots need to manually cutoff & run both switches for engine restart.
- RAT auto-deploy.
- Electrical load shedding causing less priority things to shut down temporarily or indefinitely as per situation & power available, like shut down of some of the fuel pumps, hydraulic pumps, IFES (In Flight Entertainment System), Cabin Utility, etc.

As jets become more S/w oriented with glass cockpit & automatic adjustments, that means the computers have option to relay a signal further or not triggered by a hard switch, unless the proper conditions are met. Such safety mechanisms, S/w driven locks are already there.

So now there are many layers-
- physical, mechanical layer on top.
- electronic layer of transistor circuit.
- wiring layer of connectors, plugs, copper wires, fiber optic wires.
- S/w layer, the ultimate judge, jury, executioner.

Some Avionics logic could be hard-wired where too much S/w thinking is not needed.

Each of these layer have their standards w.r.t. manufacturing, maintenance, shelf life, etc, but also gltches associated.
But we've not reached the zenith of any technology, just the beginning actually.
1 glitch at any layer may or may not be corrected at H/w or S/w aspect of other layer, depends on design efficiency, maintenance, flight conditions, operation, etc. By "swiss cheese model", if some glitch gets through all layers then problems can arise.
A glitch at electronic, wiring, S/w layers may or may not show hard movement of switch/knob/lever/button, especially in those guarded by notches, bracket, covers, etc,
Some kind of messages on MFD with LED & aural alarm may or may not occur, hence in very short life-threatening emergency situation there can be confusion/misunderstanding, especially if pilots don't get along well.

 

[Interested]

Since beginning many people like Mary Schiavo (Former IG, US DoTr), Dr. Vandana Singh, some domestic & foreign pilots, enthusiasts like me, etc have considered S/w glitch with certain functions of FMC/EEC, we should see how confusion can occur with electro-mechanical man-machine interfaces.

All switches, buttons, knobs in the A/c are some kind of electronic relays, so the electrical signals are converted by ADC (Analog to Digital Convertor) mechanism & sent to FMC & then formatted & sent to FDR.

View attachment 43500


Some of the switches, buttons, levers, knobs can be controlled back in motion by the computer/auto-pilot,
For example -
- thrust levers in auto-thrust mode.
- engine start knobs from START to NORM.
- stabilizer trim wheel (787 doesn't have).
- speed brake lever.

...except the ones guarded by notches, brackets, covers, etc. But the computer/auto-pilot can still SOFT operate the functions.
For example-
- load-relief function for flaps, but flaps lever won't move. There'll be messages, perhaps LED & aural alarm then pilot has to adjust flap lever.
- EEC's TCMA shutting down engine(fuel valves) if RPM red line crossed, overspeed occurs, ground idle RPM issues, etc. But fuel switch won't move. In case of mid-flight shutdown the pilots need to manually cutoff & run both switches for engine restart.
- RAT auto-deploy.
- Electrical load shedding causing less priority things to shut down temporarily or indefinitely as per situation & power available, like shut down of some of the fuel pumps, hydraulic pumps, IFES (In Flight Entertainment System), Cabin Utility, etc.

As jets become more S/w oriented with glass cockpit & automatic adjustments, that means the computers have option to relay a signal further or not triggered by a hard switch, unless the proper conditions are met. Such safety mechanisms, S/w driven locks are already there.

So now there are many layers-
- physical, mechanical layer on top.
- electronic layer of transistor circuit.
- wiring layer of connectors, plugs, copper wires, fiber optic wires.
- S/w layer, the ultimate judge, jury, executioner.

Some Avionics logic could be hard-wired where too much S/w thinking is not needed.

Each of these layer have their standards w.r.t. manufacturing, maintenance, shelf life, etc, but also gltches associated.
But we've not reached the zenith of any technology, just the beginning actually.
1 glitch at any layer may or may not be corrected at H/w or S/w aspect of other layer, depends on design efficiency, maintenance, flight conditions, operation, etc. By "swiss cheese model", if some glitch gets through all layers then problems can arise.
A glitch at electronic, wiring, S/w layers may or may not show hard movement of switch/knob/lever/button, especially in those guarded by notches, bracket, covers, etc,
Some kind of messages on MFD with LED & aural alarm may or may not occur, hence in very short life-threatening emergency situation there can be confusion/misunderstanding, especially if pilots don't get along well.

If and if there is the audible noise of the fuel switch moved one after another to the off position then the software fault debate is over . And the fuel switch design is made such that the sound is loud enough to be captured by the CVR. It's a distinctive click noise which can't be mistaken ,

There is no scenario in the world during take off where a pilot will move both switches to off for 10 seconds . So if the switches moved physically then it's intentional and frankly murder .