Plane Crashes

[The Mechanic]

The fault for the Air India crash is now coming back to the senior pilot in the cockpit. Apparently officials believe that his depression was a factor and that he may have switched them off intentionally. I find it hard to believe someone would kill over 200 people just to end their own life.

Captain of doomed Air India flight — who had reportedly suffered depression — may have cut off fuel flow to engines, officials believe

A black box cockpit recording of the two pilots suggests that Captain Sumeet Sabharwal was responsible for moving the fuel switches to the “cutoff” position, according to a report.

nypost.com

As far as I can tell the story blaming a pilot has been there for a week or so now, but indeed it seems to be getting traction. There's no new information though. I agree it's hard to believe someone would kill so many people along with committing suicide.

 

[Beau]

As far as I can tell the story blaming a pilot has been there for a week or so now, but indeed it seems to be getting traction. There's no new information though. I agree it's hard to believe someone would kill so many people along with committing suicide.

Yeah they're going by the CVR discussion with the FO asking why the PIC turned off the fuel switches. That's not really strong evidence. I still think it was mechanical error like @Vulcan59

 

[The Mechanic]

Just found this youtuber who seems to be an airplane mechanic of some sorts show and explain the switches and the systems around it:

The one thing that stuck out to me was that he said that the 2018 directive was only about the 737, which it isn't as far as I understand it. Otherwise a good explanation of how the system works.

 

[Possibility of Being]

I'm increasingly leaning towards the TCMA (Thrust Control Malfunction Accommodation) as the culprit. And it has happened before to an ANA flight back in 2019.

Sounds reasonable, but could you please explain in simple words how it relates to the preliminary report about the cut-off position of the switches and the short conversation in the cockpit?

My uneducated guess is that the physical position of the knobs must be set manually, not by a computer. That would mean that what was found on the flight recorder concerned the circuit switch position, not that of the knobs; and the pilots meant screen reading, not that one of them noticed the physical switches moved. No idea if I'm in any way close to making sense.


ADDED: The VASAviation guy, from the investigation report he concluded that the manual switches were moved and set in the cut-off position, so if he is right, my guess above is wrong. With that, I don't understand how TCMA can be the culprit (excluding for now the option of false claims in the report) even though I'd "prefer" it over a human act.

He focuses on differences between planes (he flies Cessna), but he does show how it works in B787.

 

[Ruth]

As far as I can tell the story blaming a pilot has been there for a week or so now, but indeed it seems to be getting traction. There's no new information though. I agree it's hard to believe someone would kill so many people along with committing suicide.

I'm wondering if a person can be 'programmed' to do stupid and dangerous things without even knowing why or how it? Like the mind control of Sirhan Sirhan? Sometimes people aren't consciously in control of their actions.

 

[Vulcan59]

Sounds reasonable, but could you please explain in simple words how it relates to the preliminary report about the cut-off position of the switches and the short conversation in the cockpit?

Not sure if one can trust the 'short conversation' in the cockpit, but lets just say it's true.

A dual engine failure at or shortly after rotation, is not something that is trained for during simulator sessions. Assuming both engines lost thrust at rotation, the captain, who was the pilot monitoring (PM), quickly reach down and put both fuel control switches to 'Cutoff' 3 seconds after liftoff! Not something that the captain with over 15000 hours flying experience would do, in my opinion! Not at that height! And if he was suicidal, why would he then put it back to 'Run' (or 'On' position in layman terms) 10 seconds after selecting 'Cutoff'? Perhaps the co-pilot who was was pilot flying (PF), put it back to 'Run'?

However, it does explain the cockpit voice recordings that the fuel control switches were put to Cutoff then Run.

My uneducated guess is that the physical position of the knobs must be set manually, not by a computer. That would mean that what was found on the flight recorder concerned the circuit switch position, not that of the knobs; and the pilots meant screen reading, not that one of them noticed the physical switches moved. No idea if I'm in any way close to making sense.

Yes. The fuel control switches have a mechanical 'gate' position. You first need to pull the switch up then forward to the 'Run' position'. To put it to 'Cutoff' position, again you need to pull it up then backwards to the 'Off' position.

The fuel control switch has a locking feature to prevent inadvertent operation that could result in unintended switch movement between the fuel supply and fuel cutoff positions. In order to move the switch from one position to the other under the condition where the locking feature is engaged, it is necessary for the pilot to lift the switch up while transitioning the switch position.
...

Recommendations

Inspect the locking feature of the fuel control switch to ensure its engagement. While the airplane is on the ground, check whether the fuel control switch can be moved between the two positions without lifting up the switch. If the switch can be moved without lifting it up, the locking feature has been disengaged and the switch should be replaced at the earliest opportunity. - Source

ADDED: The VASAviation guy, from the investigation report he concluded that the manual switches were moved and set in the cut-off position, so if he is right, my guess above is wrong. With that, I don't understand how TCMA can be the culprit (excluding for now the option of false claims in the report) even though I'd "prefer" it over a human act.

He focuses on differences between planes (he flies Cessna), but he does show how it works in B787.

So what is this TCMA? TCMA is function which can reduce thrust on both engines simultaneously. TCMA is a system to shutdown a runaway engine that's not responding to the thrust lever - basic logic is an engine at high power with the thrust lever at/near idle, and the engine not decelerating while the aircraft is on the ground. So basically it's a software driven logic that closes the HPSOV (high pressure shutoff valve) to achieve thrust reduction.

Could an air/ground logic fault inhibiting gear retraction (the gears cannot be raised up if the aircraft is on the ground - [Note] the gears were down in this accident]) caused TCMA activation just after rotation, resulting in a loss of thrust with the subsequent activation of the RAT (and the APU (which will happen in a dual engine failure scenario)?

Hoping that the final report will have more information.

 

[Possibility of Being]

So what is this TCMA? TCMA is function which can reduce thrust on both engines simultaneously. TCMA is a system to shutdown a runaway engine that's not responding to the thrust lever - basic logic is an engine at high power with the thrust lever at/near idle, and the engine not decelerating while the aircraft is on the ground. So basically it's a software driven logic that closes the HPSOV (high pressure shutoff valve) to achieve thrust reduction.

Could an air/ground logic fault inhibiting gear retraction (the gears cannot be raised up if the aircraft is on the ground - [Note] the gears were down in this accident]) caused TCMA activation just after rotation, resulting in a loss of thrust with the subsequent activation of the RAT (and the APU (which will happen in a dual engine failure scenario)?

In this case, could it be WOW sensors' malfunction that activated the TCMA?

From Inside the Black Box: How the Boeing 787 records flight data and what happens when power fails:

Air/Ground Sensing: The role of Weight-on-Wheels (WOW) sensors

One of the less discussed but critically important components in this system is the air/ground sensor, commonly referred to as the Weight-on-Wheels (WOW) switch. These sensors detect whether the aircraft is on the ground or airborne.

Located on the main landing gear struts, WOW sensors:
•Activate or deactivate systems based on aircraft status (air or ground)
•Control recorder logic (when to start/stop recording)
•Influence flight control laws, pressurisation modes, anti-skid braking, and engine idle settings

If these sensors malfunction or, worse, provide incorrect data, they can mislead automated systems into believing the aircraft is airborne when it is not, or vice versa. In previous global accidents, WOW sensor failures have contributed to incorrect thrust reverser deployment, failure of autobrake activation, and even compromised data recording.

It still wouldn't explain the allegedly registered cut-off position of the fuel control switches unless a lost of thrust was noticed and one of the pilots instinctively (in panic?) changed their positions to "fix the problem". That would make a perfect situation to be exploited so that the pilots can be presented as suicidal-murderous.

 

[Vulcan59]

In this case, could it be WOW sensors' malfunction that activated the TCMA?

Which is what I am thinking happened. Has happened before in the ANA 788 case in 2019.

My speculation - For some unexplained reason, the WOW sensors failed at liftoff (stuck at the 'On Ground' position) which explains the gear being down since the gears cannot be retracted if the aircraft is 'On Ground'.

With both thrust levers in the take-off position and the WOW sensors stuck in the 'On Ground' position, TCMA would have correctly activated and reduced thrust to below idle on both engines, as it is designed to do. That would have triggered the the RAT to deploy and the APU to auto-start as they are designed to do.

It still wouldn't explain the allegedly registered cut-off position of the fuel control switches unless a lost of thrust was noticed and one of the pilots instinctively (in panic?) changed their positions to "fix the problem". That would make a perfect situation to be exploited so that the pilots can be presented as suicidal-murderous.

The checklist for dual engine failure says "Fuel Control Switches (both) - Cutoff, then Run".

Hard to think that the captain, who was the pilot monitoring (PM), would do that moments after lift-off (wheels off the ground). If he did that, he would have instinctively selected it back to 'Run' (which is how he would have been trained to react for a dual engine failure). Instead the report says it was almost 10 seconds later when the switches were selected to 'Run' (presumably by the co-pilot who was PF). Hence the suicidal pilot narrative.

 

[Vulcan59]

Thinking about this accident, another thought occurred to me about how this accident could have happened.

On takeoff, the captain, for some inexplicable reason placed both fuel control switches to the cut-off position, not realizing that he had done so! This accounts for the cockpit voice recording in the preliminary report.

In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.

On realizing the mistake, he (the captain although the first officer could have done so too) put both switches back to the 'Run' position almost 10 seconds later. By that time, it was to late for the engines to spool up and give enough power for the aircraft to continue flying, resulting in the crash.

Sounds implausible, but stranger things have happened.

 

[Wandering Star]

On realizing the mistake, he (the captain although the first officer could have done so too) put both switches back to the 'Run' position almost 10 seconds later. By that time, it was to late for the engines to spool up and give enough power for the aircraft to continue flying, resulting in the crash.

Sounds implausible, but stranger things have happened.

In fact, you have to be (try to be) attentive, since in a distracted state of consciousness (such as performing learned mechanical acts) "someone" can make us do things.

I'm pretty sure you've already experienced some of this.

We are distractedly picking up a glass and our hand moves where it shouldn't and the glass slips away and breaks, creating a nice angry atmosphere for the people around us for a while.

So there could be some outside influence capable of doing that.

 

[Joe]

While pilot error is possible, I'm still leaning to it being a mechanical or electrical failure as the cause, mainly because this isn't the first time Boeing has been caught in dodgy workmanship.

 

[Possibility of Being]

Thinking about this accident, another thought occurred to me about how this accident could have happened.

On takeoff, the captain, for some inexplicable reason placed both fuel control switches to the cut-off position, not realizing that he had done so! This accounts for the cockpit voice recording in the preliminary report.

That's the only option (apart from deliberate suicidal act) that explains the switches' position. If none of the pilots did it, then there seem to be only two options left:

• the switches' malfunction, each changing its position by its own, all within 1 sec (not very likely)
• the preliminary report's claim is false; WOW sensors/ TCMA back on the table

Speculation attempt re 2nd point: one EAFR unit is badly damaged so it seems double confirmation is not possible (how convenient!); the other one, as speculated due to such an option been officially considered then denied, was sent to Washington and that's why it took so long to start reading it. Could it be possible for the NTSB to insert the data? If yes, would they do it? Is it also why the investigators couldn't recognise the pilots' voices to know which one asked the alleged question and which one answered it?​

​

OK, enough, it looks like opening a Pandora's box.​

 

[Charade]

Delta pilot's 'aggressive maneuver' evades B-52 bomber, prevents mid-air collision in harrowing flight nightmare

Delta pilot’s ‘aggressive maneuver’ evades B-52 bomber, prevents mid-air collision in harrowing flight nightmare

This is a SkyWest pilot, the company I worked for and my husband flies for as a Captain.

Great work crew! The passengers sound like they reacted sensibly too. That’s a huge plus.

 

[ivanb]

Delta's close call with B-52 bomber.

 

[Charade]

Delta pilot's 'aggressive maneuver' evades B-52 bomber, prevents mid-air collision in harrowing flight nightmare

Delta pilot’s ‘aggressive maneuver’ evades B-52 bomber, prevents mid-air collision in harrowing flight nightmare

This is a SkyWest pilot, the company I worked for and my husband flies for as a Captain.

Great work crew! The passengers sound like they reacted sensibly too. That’s a huge plus.

Update. Word from management on this incident. It was about 4-5 miles separation. ATC told the pilot to turn right but he saw the bomber aircraft and told the controller he was turning left. This is all well and good. The Captain acted appropriately. The problem that Skywest has with it is the announcement to the passengers so that got this on the social media. Delta is pissed off. Personally, I like that the Captain kept the passengers informed but it’s like everything anymore, keep the public clueless and in the dark.