Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Preliminary report into Air India crash released

bbc.co.uk

Post reply on HN
Print view View original

271–280 of 924 posts

Re: Preliminary report into Air India crash released

#271

Post by sugarpimpdorsey »

lazystar wrote: post #17
decimalenough wrote: post #11

> The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off. So the fuel supply was cut off intentionally. The swi…

https://ad.easa.europa.eu/ad/NM-18-33 well hold your horses there... from the FAA in their 2019 report linked above: > The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to sup…

Totally different airplane with a totally different flight deck, designed generations apart. The fact that the manufacturer is the same is irrelevant.

You are trying to draw parallels between the ignition switch in a 1974 Ford Pinto and a 2025 Ford Mustang as if there could be a connection. No.

Re: Preliminary report into Air India crash released

#272

Post by cosmicgadget »

lanna wrote: post #179
cosmicgadget wrote: post #114

Earlier quoted context omitted.

Did you mean to say you can activate the switches with one hand simultaneously ? That is probably what the above commenter assumed you meant. Since lifting and twisting two switches simultaneously with one hand seems challenging.

Above commenter said _quickly_, not simultaneously

Jesus...

joey: Can you switch them quickly?

snypher: You can do them with one hand. [Ed. This is ambiguous and could be read as "one hand, simultaneously". In fact, doing it with one hand non-simultaneously would be a weird claim to make of a simple knob. See also ajb's comment below.]

zihotki: Really? They are not close together and have a spring mechanism. [Ed. Seems to believe snypher is claiming simultaneous operation.]

snypher: I am confused by the response.

Me: [Tries to facilitate clarification]

Re: Preliminary report into Air India crash released

#273

Post by sbuttgereit »

sugarpimpdorsey wrote: post #271
lazystar wrote: post #17

Earlier quoted context omitted.

https://ad.easa.europa.eu/ad/NM-18-33 well hold your horses there... from the FAA in their 2019 report linked above: > The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to sup…

Totally different airplane with a totally different flight deck, designed generations apart. The fact that the manufacturer is the same is irrelevant. You are trying to draw parallels between the ignition switch in a 1974 Ford Pinto and a 2025 Ford Mustang as if there could be a connection. No.

And yet the preliminary report for the incident in question includes reference to that bulletin, indicates that the switches in the accident aircraft were of a very similar design and subject to advisory inspections:

"The FAA issued Special Airworthiness Information Bulletin (SAIB ) No. NM -18-33 on December 17, 2018, regarding the potential disengagement ofthe fuel control switch locking feature. This SAIB was issued based on reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The airworthiness concern was not considered an unsafe condition that would warrant airworthiness directive (AD) by the FAA. The fuel control switch design , including the locking feature, is similar on various Boeing airplane models including part number 4TL837-3D which is fitted in B787-8 aircraft VT-ANB. As per the information from Air India, the suggested inspections were not carried out asthe SAIB was advisory and not mandatory. The scrutiny ofmaintenance records revealed that the throttle control module was replaced on VT-ANB in 2019 and 2023. However, the reason for the replacement was not linked to the fuel control switch. There has been no defect reported pertaining to the fuel control switch since 2023 on VT-ANB."

So while I agree that this being the cause sounds unlikely, referencing the switch issue is something relevant enough for the report itself.

Re: Preliminary report into Air India crash released

#274

Post by mitthrowaway2 »

aerospace83 wrote: post #132
xenadu02 wrote: post #40

Earlier quoted context omitted.

It could be defective switch springs, fatigue-induced muscle memory error, or something else. The pilot who did it saying he did not may not have realized what he did. It's pretty common under high workload when you flip the wrong switch or move a control the wrong way to think that you did what you intended to do, not what you actually did. That said Boeing could take a page out of the Garmin GI275. When power is re…

[flagged]

Yeah, people shouldn't bat ideas around and read replies from other people about why those ideas wouldn't work. Somebody might learn something, and that would be bad.

Re: Preliminary report into Air India crash released

#275

Post by burnt-resistor »

decimalenough wrote: post #11

> The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off. So the fuel supply was cut off intentionally. The swi…

> It's difficult to conclude anything other than murder-suicide.

You're leaping into the minds of others and drawing conclusions of their intent. One of them moved the levers. It could've been an unplanned reaction, a terrible mistake, or it could've been intentional. We may never know the intention even with a comprehensive and complete investigation. To claim otherwise is arrogance.

Re: Preliminary report into Air India crash released

#276

Post by sugarpimpdorsey »

bombcar wrote: post #92
cosmicgadget wrote: post #51

Earlier quoted context omitted.

Cutting fuel just after takeoff leaves almost zero time for the other pilot to recover.

It's interesting to try to imagine a device that would prevent that, without causing more issues. My preliminary idea is a "fuel bladder" for take-off that inflates with enough fuel to get the plane to a recoverable altitude, maybe a few thousand feet?

> My preliminary idea is a "fuel bladder" for take-off that inflates

Will the bladder be marketed by Kramerica Industries?

Re: Preliminary report into Air India crash released

#277

Post by burnt-resistor »

cjbprime wrote: post #156
russdill wrote: post #124

Earlier quoted context omitted.

There is no possible way to confuse these two actions. There's a reason a wheel is attached to the gear lever.

> There is no possible way to confuse these two actions. This is obviously an overstatement. Any two regularly performed actions can be confused. Sometimes (when tired or distracted) I've walked into my bathroom intending to shave, but mistakenly brushed my teeth and left. My toothbrush and razor are not similar in function or placement.

Even humans have fixed action patterns. Much behavior is barely under conscious control.

Re: Preliminary report into Air India crash released

#278

Post by burnt-resistor »

sxg wrote: post #197
resize2996 wrote: post #175

[flagged]

Studying how humans make errors is a fascinating field. Simply banning someone who's made a "slip" error as hypothesized wouldn't actually reduce the likelihood of this error occurring in the future. These sorts of errors are stochastic and could happen to anyone at any time. Preventing them requires a lot of thought.

Human factors portion of the investigation.

Re: Preliminary report into Air India crash released

#279

Post by sandspar »

Anishx7 wrote: post #226

reached v1, then when airborn fuel cut off. Seems like there was a FAA report like in 2018 that recommended few airplane models (incl this one) to check the fuel valves correctly, seems like air india didn't do it. Turns out it was made by Honeywell

All evidence suggests that the plane was fully functional. The switches were moved by one of the pilots.
Post reply on HN