July 14, 2025, 16:30:00 GMT
permalink Post: 11922344
Why is the report worded this way, and not that way?
The preliminary report narrows things down a lot but not as much as it could have done. The report will have been approved by several people. What we see is their consensus. Why did they choose this version?
The report is written to point the finger directly at: (i) the fuel cutoff switches and (ii) either pilot error or pilot mal-intent using them. The report is not written to point the finger at an electrical or mechanical malfunction.
We have all role-played in our heads what would have been said in the cockpit in different scenarios. The investigating team already knows. They could have disclosed more of the cockpit conversation, which would be a lot of help to us PPRuNers, but didn't need to. They have let Boeing and the type off the hook and put the blame on the pilots. They have fulfilled the primary purpose of an investigation -- to find out what happened.
Interestingly, they did not disclose whether it was error and mal-intent. Perhaps that is because they couldn't answer the grisly question: which is least worst, from the point-of-view of the airline, the victims' families and future customers?
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
The report is written to point the finger directly at: (i) the fuel cutoff switches and (ii) either pilot error or pilot mal-intent using them. The report is not written to point the finger at an electrical or mechanical malfunction.
We have all role-played in our heads what would have been said in the cockpit in different scenarios. The investigating team already knows. They could have disclosed more of the cockpit conversation, which would be a lot of help to us PPRuNers, but didn't need to. They have let Boeing and the type off the hook and put the blame on the pilots. They have fulfilled the primary purpose of an investigation -- to find out what happened.
Interestingly, they did not disclose whether it was error and mal-intent. Perhaps that is because they couldn't answer the grisly question: which is least worst, from the point-of-view of the airline, the victims' families and future customers?
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
4 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 16:41:00 GMT
permalink Post: 11922355
Why do you think it is a "fact that nobody apparently announced 'engine failure'?" That was not included in the preliminary report or, as far as I know, in any other credible reporting here or elsewhere.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 16:53:00 GMT
permalink Post: 11922363
The preliminary report narrows things down a lot but not as much as it could have done. The report will have been approved by several people. What we see is their consensus. Why did they choose this version?
.....
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
.....
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
2 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 16:57:00 GMT
permalink Post: 11922366
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
YYZJim
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 17:26:00 GMT
permalink Post: 11922380
Good analysis; AvH MN4 thing is an absolute ruse
The preliminary report narrows things down a lot but not as much as it could have done. The report will have been approved by several people. What we see is their consensus. Why did they choose this version?
The report is written to point the finger directly at: (i) the fuel cutoff switches and (ii) either pilot error or pilot mal-intent using them. The report is not written to point the finger at an electrical or mechanical malfunction.
...... The investigating team already knows. They could have disclosed more of the cockpit conversation, which would be a lot of help to us PPRuNers, but didn't need to. They have let Boeing and the type off the hook and put the blame on the pilots. They have fulfilled the primary purpose of an investigation -- to find out what happened.
Interestingly, they did not disclose whether it was error and mal-intent. Perhaps that is because they couldn't answer the grisly question: which is least worst, from the point-of-view of the airline, the victims' families and future customers?
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
The report is written to point the finger directly at: (i) the fuel cutoff switches and (ii) either pilot error or pilot mal-intent using them. The report is not written to point the finger at an electrical or mechanical malfunction.
...... The investigating team already knows. They could have disclosed more of the cockpit conversation, which would be a lot of help to us PPRuNers, but didn't need to. They have let Boeing and the type off the hook and put the blame on the pilots. They have fulfilled the primary purpose of an investigation -- to find out what happened.
Interestingly, they did not disclose whether it was error and mal-intent. Perhaps that is because they couldn't answer the grisly question: which is least worst, from the point-of-view of the airline, the victims' families and future customers?
Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.
YYZJim
1 user liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 17:48:00 GMT
permalink Post: 11922392
Two questions for
tdracer
:
1. What happens to the FADEC channels if both channels have different data / information (e.g. T/L encoders or fuel switches)?
- Will the currently active channel win?
- Or will the most sensible information be used (e.g. keep the engines running)?
- Will there be a disagree message?
- Logged to the DFDR?
2. As per the data sheet the fuel switches are 4 pole versions. 1 pole will be used for each FADEC channel. Will one (or both) of the other poles be used for the DFDR or is that information collected from the FADEC through some data bus?
I know, it's very specific stuff that might only be known by the designer of the FADEC system.
1. What happens to the FADEC channels if both channels have different data / information (e.g. T/L encoders or fuel switches)?
- Will the currently active channel win?
- Or will the most sensible information be used (e.g. keep the engines running)?
- Will there be a disagree message?
- Logged to the DFDR?
2. As per the data sheet the fuel switches are 4 pole versions. 1 pole will be used for each FADEC channel. Will one (or both) of the other poles be used for the DFDR or is that information collected from the FADEC through some data bus?
I know, it's very specific stuff that might only be known by the designer of the FADEC system.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 18:16:00 GMT
permalink Post: 11922406
Two questions for
tdracer
:
1. What happens to the FADEC channels if both channels have different data / information (e.g. T/L encoders or fuel switches)?
- Will the currently active channel win?
- Or will the most sensible information be used (e.g. keep the engines running)?
- Will there be a disagree message?
- Logged to the DFDR?
2. As per the data sheet the fuel switches are 4 pole versions. 1 pole will be used for each FADEC channel. Will one (or both) of the other poles be used for the DFDR or is that information collected from the FADEC through some data bus?
I know, it's very specific stuff that might only be known by the designer of the FADEC system.
1. What happens to the FADEC channels if both channels have different data / information (e.g. T/L encoders or fuel switches)?
- Will the currently active channel win?
- Or will the most sensible information be used (e.g. keep the engines running)?
- Will there be a disagree message?
- Logged to the DFDR?
2. As per the data sheet the fuel switches are 4 pole versions. 1 pole will be used for each FADEC channel. Will one (or both) of the other poles be used for the DFDR or is that information collected from the FADEC through some data bus?
I know, it's very specific stuff that might only be known by the designer of the FADEC system.
Again, not familiar with the specifics of the 787, but on the 747-400/-8, one pole of the fuel switch feeds EICAS - which uses it in various message logic - and sends it out to any other aircraft systems that use it. There is "Digital Flight Data Acquisition Unit) DFDAU (pronounced Daff Du) that takes all the various system digital signals, sorts them and provides them to the DFDR and QAR. The 787 has something similar to the DFDAU but I don't recall what it's called.
9 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 18:50:00 GMT
permalink Post: 11922425
... The fuel switch discrete doesn't really get used except for engine start - if it falsely indicates shutdown (on one or both channels), the FADEC won't do anything if the engine is already running. All this will set maintenance faults - and associated EICAS Status messages (L/R ENGINE CONTROL or ENGINE C1)...
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 19:35:00 GMT
permalink Post: 11922444
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
4 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 19:41:00 GMT
permalink Post: 11922448
If you think everything is said...
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
FWIW I don't think everything is said, and further elements may be uncovered - I just think the investigators have laid out pretty clearly areas they think are (and are not) likely causes when you read between the lines.
Incidentally the above smacks of optics to me following it being shared that air India had not performed these checks, and the associated speculation of cause, but that's just a theory 😉
2 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 19:47:00 GMT
permalink Post: 11922454
Upfront: Sorry for my initial post on the topic, like some other people in this thread it obviously touches a nerve and was rightly removed for exceeding the rules of civil discussion.
This is my attempt to shed a bit of light on why I find pushing theories of suicide very objectionable at this point in time.
Let's actually run some numbers here.
https://www.boeing.com/content/dam/b...df/statsum.pdf gives us a nice statistic over the last 20 years and also has this little tidbit:
"965 million departures since 1959. 63% of those departures were on Boeing airplanes. (609 million on Boeing airplanes)"
For the last 20 years I'd eyeball an average of between 20-25 million departures per year. So 400-500 million flights in just 20 years. Maybe let that sink in for a moment. We have doubled the total number of flights in the 20 years since 2005.
In that timeframe we have:
Nov 2013, LAM 470, 33 fatalities, confirmed by CVR
Mar 2015, Germanwings 9525, 150 fatalities, confirmed by CVR
There are additionally these:
Mar 2014, MH370, 239 fatalities, no final report, no information available
Mar 2022, CES5735, 132 fatalities, no final report, media reports claiming pilot suicide, strong counter by the investigating agency: "CAAC has previously said speculation surrounding the crash had "gravely misled the public" and interfered with accident investigation work."
Both confirmed cases in that time have a very clear pattern that does in no way resemble the Air India Crash.
Even beyond that timeframe no confirmed pilot suicide involved any measures against discovery by the departed.
There is speculation regarding Silk Air 185 because the CVR failed to record the relevant part of the accident, but it is firmly in the "debated" category.
But we can ignore all of that. Even if we put any theoretically possible Pilot Suicide into the equation one fact remains: The actual likeliness of pilot suicide has not changed. There were 2 confirmed prior to 2005 and 2 after and 2 suspected prior to 2005 2 and after. And that is despite a higher sensitivity and a more stressful job as well as significantly increased environmental stress factors. Obviously we are talking about, statistically speaking, numbers too small for analysis, but all of this is actually well within expected parameters. The recent years have seen a focus on mental health in general in many countries worldwide, and mental healthcare availability is growing in most countries. And here the US is a great example as far as aviation goes: https://casten.house.gov/media/press...tion-committee With this bill whose merit can be assessed by the people supporting it: " The legislation is endorsed by the Pilot Mental Health Campaign, Air Line Pilots Association, Airlines for America, the National Air Traffic Controllers Association, National Flight Training Alliance, the National Business Aviation Association, and NetJets Association of Shared Aircraft Pilots (NJASAP)."
Summing up I would like to point out that there are good indications that there are no mental health issues involved here. Taking the aforementioned accidents as reference the issues were usually quite obvious once any kind of scrutiny was placed on the individuals involved. The individuals also made little to no effort of concealment in all confirmed cases and while the absence of evidence can be interpreted as indicative of successful concealment it is not proof and cannot be treated as such. Especially when it is documented that the overwhelming majority of suicides do not involve any element of concealment, and the psychological mechanisms at work commonly preclude any thought about what happens after, as far as medical study of the issue is concerned. This does not mean it does not happen, cases of concealment attempts or even partial successes are well documented, but it is a lot less prevalent. In this case estimates range mostly from between 10% to 30% of all suicides being misreported as unintentional injury with massive variation depending on multiple factors like country, ethnicity, gender, sexual identity, etc.
In final conclusion: Anyone can make mistakes. It is possible one or both of these pilots made a mistake. It is also possible that a combination of bad luck lead to an alignment of the holes. In my opinion the inability to receive urgently required medical support is as much a hole in the Swiss Cheese as the worst maintenance or design error imaginable. We know from the previous discussions in all threads on this Accident and the report itself that the pilots were flying their aircraft until they ran out of time and airspace. One cannot demand more from a human being, no matter what the final cause is ultimately determined to be.
This is my attempt to shed a bit of light on why I find pushing theories of suicide very objectionable at this point in time.
Let's actually run some numbers here.
https://www.boeing.com/content/dam/b...df/statsum.pdf gives us a nice statistic over the last 20 years and also has this little tidbit:
"965 million departures since 1959. 63% of those departures were on Boeing airplanes. (609 million on Boeing airplanes)"
For the last 20 years I'd eyeball an average of between 20-25 million departures per year. So 400-500 million flights in just 20 years. Maybe let that sink in for a moment. We have doubled the total number of flights in the 20 years since 2005.
In that timeframe we have:
Nov 2013, LAM 470, 33 fatalities, confirmed by CVR
Mar 2015, Germanwings 9525, 150 fatalities, confirmed by CVR
There are additionally these:
Mar 2014, MH370, 239 fatalities, no final report, no information available
Mar 2022, CES5735, 132 fatalities, no final report, media reports claiming pilot suicide, strong counter by the investigating agency: "CAAC has previously said speculation surrounding the crash had "gravely misled the public" and interfered with accident investigation work."
Both confirmed cases in that time have a very clear pattern that does in no way resemble the Air India Crash.
Even beyond that timeframe no confirmed pilot suicide involved any measures against discovery by the departed.
There is speculation regarding Silk Air 185 because the CVR failed to record the relevant part of the accident, but it is firmly in the "debated" category.
But we can ignore all of that. Even if we put any theoretically possible Pilot Suicide into the equation one fact remains: The actual likeliness of pilot suicide has not changed. There were 2 confirmed prior to 2005 and 2 after and 2 suspected prior to 2005 2 and after. And that is despite a higher sensitivity and a more stressful job as well as significantly increased environmental stress factors. Obviously we are talking about, statistically speaking, numbers too small for analysis, but all of this is actually well within expected parameters. The recent years have seen a focus on mental health in general in many countries worldwide, and mental healthcare availability is growing in most countries. And here the US is a great example as far as aviation goes: https://casten.house.gov/media/press...tion-committee With this bill whose merit can be assessed by the people supporting it: " The legislation is endorsed by the Pilot Mental Health Campaign, Air Line Pilots Association, Airlines for America, the National Air Traffic Controllers Association, National Flight Training Alliance, the National Business Aviation Association, and NetJets Association of Shared Aircraft Pilots (NJASAP)."
Summing up I would like to point out that there are good indications that there are no mental health issues involved here. Taking the aforementioned accidents as reference the issues were usually quite obvious once any kind of scrutiny was placed on the individuals involved. The individuals also made little to no effort of concealment in all confirmed cases and while the absence of evidence can be interpreted as indicative of successful concealment it is not proof and cannot be treated as such. Especially when it is documented that the overwhelming majority of suicides do not involve any element of concealment, and the psychological mechanisms at work commonly preclude any thought about what happens after, as far as medical study of the issue is concerned. This does not mean it does not happen, cases of concealment attempts or even partial successes are well documented, but it is a lot less prevalent. In this case estimates range mostly from between 10% to 30% of all suicides being misreported as unintentional injury with massive variation depending on multiple factors like country, ethnicity, gender, sexual identity, etc.
In final conclusion: Anyone can make mistakes. It is possible one or both of these pilots made a mistake. It is also possible that a combination of bad luck lead to an alignment of the holes. In my opinion the inability to receive urgently required medical support is as much a hole in the Swiss Cheese as the worst maintenance or design error imaginable. We know from the previous discussions in all threads on this Accident and the report itself that the pilots were flying their aircraft until they ran out of time and airspace. One cannot demand more from a human being, no matter what the final cause is ultimately determined to be.
ANY Boeing pilot who grabs for the FCSs immediately after takeoff has SOME type of mental health issue. It might be suicidal, it might be cognitive, it might be a stroke, it might be some type of blood interruption to the brain, chemical imbalance, drug reaction, or whatever.
It’s not a simple mistake.
I’m not saying it’s necessary deliberate or homicidal (which it could be) but there is some type of impairment there. Everyone knows the consequences of shutting off a FCS or pulling a fire handle. The switches aren’t easily confused with others. Bumping them doesn’t cause them to go to cut off. And have dire consequences if actuated at the wrong time.
I guess there might theoretically be a way to snag them with loose clothing (like having a very frayed sweater with holes in the sleeve putting one’s arm in a really strange place) somehow and while pulling to free it manage to pull them out and down but I’m going to put this in the asteroid hitting earth category.
1 user liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 19:53:00 GMT
permalink Post: 11922462
I find it hard to believe that, in this instance, there is anything inherently wrong in the aircraft or its associated powerplants. The report appears to indicate that all the correct parameters had been met with regard to W&B and performance planning whilst the aircraft was performing normally until just after rotate.
The apparent lack of information with regard to the CVR transcript appears to be telling. If the F/O was handling pilot using a mixture of visual references and the HUD, one wonders what he would have seen or sensed to make him ask the question ‘why did you do that ?’ when it became apparent through Eicas or simple loss of thrust that the engines had shut down - his remark is very specific and not perhaps the normal expletive ridden response that one might expect.
Again, here, I am making as assumption that the initial remark was made by the FO because the report does not tell us who said what. Whilst it may be easy to jump on the bandwagon of the deliberate and premeditated act I would still give some credence to the idea that the fuel control switches were actioned in a completely erroneous act if for no other reason that I have seen similar faux pas in the simulator on multiple occasions.
There may of course be a cultural issue in play here with the relationship between the two pilots which has been seen in many previous accidents/incidents. Equally the strange timing of the releasing of the report potentially raises a question or two though maybe that is a conspiracy theory too far !
The apparent lack of information with regard to the CVR transcript appears to be telling. If the F/O was handling pilot using a mixture of visual references and the HUD, one wonders what he would have seen or sensed to make him ask the question ‘why did you do that ?’ when it became apparent through Eicas or simple loss of thrust that the engines had shut down - his remark is very specific and not perhaps the normal expletive ridden response that one might expect.
Again, here, I am making as assumption that the initial remark was made by the FO because the report does not tell us who said what. Whilst it may be easy to jump on the bandwagon of the deliberate and premeditated act I would still give some credence to the idea that the fuel control switches were actioned in a completely erroneous act if for no other reason that I have seen similar faux pas in the simulator on multiple occasions.
There may of course be a cultural issue in play here with the relationship between the two pilots which has been seen in many previous accidents/incidents. Equally the strange timing of the releasing of the report potentially raises a question or two though maybe that is a conspiracy theory too far !
1 user liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 19:59:00 GMT
permalink Post: 11922466
If you think everything is said...
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
Realize this is a pilots forum, and its always easier to blame the engineers (me), but I'm surprised at the amount of people grasping at (at least what I think) straws to try and make this not a case of pilot error (either intentional or unintentional). I get lots of parts frequently break and pilots do frequently see things on MEL etc. I know our partner airline engineering teams would love to see increased reliability of certain components, but the certification scrutiny of flight critical items is very intense including isolation from each other.
The likelihood of two flight critical components which are isolated from each other failing instantaneously is so small its basically impossible. Especially when you consider they also turn back on 10 secs later.
Last edited by T28B; 14th July 2025 at 20:57 . Reason: pulled out the bottom line with formatting
6 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 20:32:00 GMT
permalink Post: 11922481
Again, not familiar with the specifics of the 787, but on the 747-400/-8, one pole of the fuel switch feeds EICAS - which uses it in various message logic - and sends it out to any other aircraft systems that use it. There is "Digital Flight Data Acquisition Unit) DFDAU (pronounced Daff Du) that takes all the various system digital signals, sorts them and provides them to the DFDR and QAR. The 787 has something similar to the DFDAU but I don't recall what it's called.
The EAFRs simply sniff the required data from the CDN, so there's no DFDAU as such.
For some parameters, including the fuel cutoff switches, the EAFRs also record a "Source Index." For the fuel cutoff switches, there are 4 sources numbered 1 through 4 as well as a valid/invalid flag. I don't know what the sources are, but perhaps they're the 2 RDCs plus the 2 channels of the EEC/FADEC. It appears that source 1 (the default) is not the EEC.
1 user liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 20:46:00 GMT
permalink Post: 11922486
Which leads to a very unpleasant possibility that many people would rather not consider, and some even refuse to consider, despite there being at least one historical precedent that I can think of (a pilot for a particular airline many years ago who had an undiagnosed mental health condition and admitted to struggling with impulsive thoughts of shutting down all 4 engines on a B747).
11 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 20:51:00 GMT
permalink Post: 11922492
If you think everything is said...
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
Breaking News:
On Jul 14th 2025 India's DGCA instructed airlines to check the fuel switches on the Boeing 787 and Boeing 737 aircraft as used by Air India Group, Indigo and Spicejet for possible disengagement of the fuel control switch locking feature according to the SAIB released by the FAA on Dec 17th 2018. The checks have to be completed by Jul 21st 2025.
Source: Avherald.com
1 user liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 21:01:00 GMT
permalink Post: 11922500
I'm not surprised though it gets frustrating when folk start defaulting to the most remote possibilities instead of the more likely ones. The flight data recorder logged the fact that the switches were moved to cutoff, 1 second apart, very soon after airborne, then some seconds later moved back to run. None of that fits with any realistically conceivable mechanical failure nor automated system fault. Both of those are physical actions taken by a pilot. The first action was to shut them down, and the second action was an attempt to start them up again (tragically close to being successful). Nor does it fit with a muscle memory mistake or confusion with another switch.
Which leads to a very unpleasant possibility that many people would rather not consider, and some even refuse to consider, despite there being at least one historical precedent that I can think of (a pilot for a particular airline many years ago who had an undiagnosed mental health condition and admitted to struggling with impulsive thoughts of shutting down all 4 engines on a B747).
Which leads to a very unpleasant possibility that many people would rather not consider, and some even refuse to consider, despite there being at least one historical precedent that I can think of (a pilot for a particular airline many years ago who had an undiagnosed mental health condition and admitted to struggling with impulsive thoughts of shutting down all 4 engines on a B747).
2 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 21:09:00 GMT
permalink Post: 11922503
Again, not familiar with the specifics of the 787, but on the 747-400/-8, one pole of the fuel switch feeds EICAS - which uses it in various message logic - and sends it out to any other aircraft systems that use it. There is "Digital Flight Data Acquisition Unit) DFDAU .... that takes all the various system digital signals, sorts them and provides them to the DFDR and QAR. The 787 has something similar to the DFDAU but I don't recall what it's called.
The other 2 contact sets feed latching relays (again driven each coil independently by dropping to GND at the switch) that then drive spar valves and reset signals to the FADEC Channels. (and more).
So - for the benefit of those that hang on to the 'possibility' of electrical gremlins and 'ghost' switch signals.
Each switch has 4 mechanically separated 'channels' - 2 of which do electromechanical things to the engines through separate paths, the other 2 feed through independent paths the FDR and the rest of the computer systems. The results of the electromechanical actions also feed back to the FDR.
Thus the readout from the EAFR will PROVE that the switches MUST have been PHYSICALLY MOVED.
And - I'm nervous to challenge you tdracer - there's quite the authority gradient and I know I'm at the bottom end, but I can't let this fly...
Its 'Deefer Doo'. Fight me.
19 users liked this post.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 21:11:00 GMT
permalink Post: 11922506
I'm still not clear on something, no surprise there.
If you are the PF and you are just after rotation, and for whatever reason, the fuel control switches transition to "CUTOFF", when and how do you notice this?
Presumably your hands are on the yoke and you are looking very intently out the windshield. So, to me it seems unlikely that you saw whatever happened to the switches, however they moved.
Do you get a warning indication that the switches have moved? If so, then that would be what I needed to know. You got a warning and therefore you looked right at the switches.
If not, do you just notice that you have lost power? If that is the case, where do you look first? I presume it would be at the engine info gauges/displays.
What I'm getting at is what priority is given to looking at the fuel cutoff switches in this situation?
How long until you look at those switches as the possible cause of the engine problems?
If you are the PF and you are just after rotation, and for whatever reason, the fuel control switches transition to "CUTOFF", when and how do you notice this?
Presumably your hands are on the yoke and you are looking very intently out the windshield. So, to me it seems unlikely that you saw whatever happened to the switches, however they moved.
Do you get a warning indication that the switches have moved? If so, then that would be what I needed to know. You got a warning and therefore you looked right at the switches.
If not, do you just notice that you have lost power? If that is the case, where do you look first? I presume it would be at the engine info gauges/displays.
What I'm getting at is what priority is given to looking at the fuel cutoff switches in this situation?
How long until you look at those switches as the possible cause of the engine problems?
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
July 14, 2025, 21:23:00 GMT
permalink Post: 11922512
I'm still not clear on something, no surprise there.
If you are the PF and you are just after rotation, and for whatever reason, the fuel control switches transition to "CUTOFF", when and how do you notice this?
Presumably your hands are on the yoke and you are looking very intently out the windshield. So, to me it seems unlikely that you saw whatever happened to the switches, however they moved.
Do you get a warning indication that the switches have moved? If so, then that would be what I needed to know. You got a warning and therefore you looked right at the switches.
If not, do you just notice that you have lost power? If that is the case, where do you look first? I presume it would be at the engine info gauges/displays.
What I'm getting at is what priority is given to looking at the fuel cutoff switches in this situation?
How long until you look at those switches as the possible cause of the engine problems?
If you are the PF and you are just after rotation, and for whatever reason, the fuel control switches transition to "CUTOFF", when and how do you notice this?
Presumably your hands are on the yoke and you are looking very intently out the windshield. So, to me it seems unlikely that you saw whatever happened to the switches, however they moved.
Do you get a warning indication that the switches have moved? If so, then that would be what I needed to know. You got a warning and therefore you looked right at the switches.
If not, do you just notice that you have lost power? If that is the case, where do you look first? I presume it would be at the engine info gauges/displays.
What I'm getting at is what priority is given to looking at the fuel cutoff switches in this situation?
How long until you look at those switches as the possible cause of the engine problems?
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.