Air India 787 crashes on take off 12

[LittleInch]

A full 787-8 has crashed shortly after take off in ahmedabad.

Basically barely got off the ground then look like its trying to land in this video.

Air India ordered to carry out ‘additional maintenance actions’ on Boeing 787-8/9 fleet – as it happened

India’s ministry of civil aviation orders airline to carry out safety inspections on fleet with GE Aerospace GEnx engines after crash of flight 171

www.theguardian.com

Specualtion that they pulled flaps up instead of gear up and basically didn't have enough lift so it looks like a gentle stall right into a built up area.

Looks to be flaps up, slats/ nose flaps down and gear down which is very odd.

 

[IRstuff]

Lots of people trying to deflect attention from intentional pilot action. Jeff Ostroff attributes this to a national pride thing in India, but this guy doesn't appear to be doing that, exactly.

What this "expert" says is inconsistent with what's in the preliminary report's voice recording. Specifically, one pilot asks the other why they did a cutoff; if it had been an electrical failure, the pilot response would have been, "WTF, we lost power, try restarting fuel" since the fuel cutoff would have occurred with the fuel switches in the ON position.

And, the data recorder shows switches moved to the OFF position prior to loss of fuel, which would not be the case if some control chip crapped out, since the switches would still have been in the ON positions. This is coupled with data recording of the switches going to the ON position 10 seconds later; a chip failure would show switches in ON position through the loss of fuel, followed by a quick OFF, the ON again as the pilots attempted to restart the engines.

 

[TugboatEng]

IRStuff, it is possible the switch failed to transmit the signal correctly. I recently inherited some equipment that uses a relay to interlock a 0-10V process signal. Because of the low current the relay would randomly fail to transmit the signal correctly. I was able to resolve the issue by converting the signal to a current signal prior to the relay contacts. With digital controls, mechanical switches provide poor closing reliability. I think this is an issue that many engineers may not be aware of and needs to be emphasized for attention.

 

[Alistair_Heaton]

There must also be redundant FADEC controllers on each engine?

There are 3 channels on mine 2 primary which swap every engine start and an emergency backup. The engines can also cross talk so even if one engine has lost all 3 the other takes over. One channel can look after both engines solo i believe.

There will be something in that mel for redundancy downgrades of fadec.

 

[LittleInch]

Lots of people trying to deflect attention from intentional pilot action. Jeff Ostroff attributes this to a national pride thing in India, but this guy doesn't appear to be doing that, exactly.

What this "expert" says is inconsistent with what's in the preliminary report's voice recording. Specifically, one pilot asks the other why they did a cutoff; if it had been an electrical failure, the pilot response would have been, "WTF, we lost power, try restarting fuel" since the fuel cutoff would have occurred with the fuel switches in the ON position.

And, the data recorder shows switches moved to the OFF position prior to loss of fuel, which would not be the case if some control chip crapped out, since the switches would still have been in the ON positions. This is coupled with data recording of the switches going to the ON position 10 seconds later; a chip failure would show switches in ON position through the loss of fuel, followed by a quick OFF, the ON again as the pilots attempted to restart the engines.

I agree with you.

The interim report threw a couple of red herrings into the mix, specifically the issue of whether the cut off switches locking mechanism "might" have been inoperative, but in all these software / electric circuitry potential causes, the possibility of TWO failing within one second of each other and as you say, the response of one of the pilots being "why did you cut off the fuel supply?", not "why have we lost fuel supply?" is very telling assuming that these are true quotes. There is also a leak that the pilot asking this did so two or three times before - maybe - taking his hand off the control column and switching them back on himself. No wonder it took 10 seconds.