A couple of days ago, India’s Aircraft Accident Investigation Bureau (AAIB) released its preliminary report into the tragedy of Air India flight AI171, the Boeing 787-8 that crashed seconds after taking off from Ahmedabad, killing 260 people.
The preliminary report simply shares the facts as they’re known, and doesn’t draw any conclusions. That being said, the United States’ Federal Aviation Administration (FAA) has just released a memo about the Boeing 787 fuel control switches, which is pretty telling…
In this post:
FAA suggests fuel control switches were moved manually
As a reminder, the investigation into the crash of AI171 is centered around the aircraft’s fuel control switches. Investigators know that these were moved from the “RUN” to “CUTOFF” position just moments after takeoff, one second apart.
Ordinarily, these switches are only moved on the ground when starting or stopping engines, or in the air during an emergency. However, you’d never use them just seconds after takeoff, when there are no signs of engine issues, since there’s no chance to recover at such a low altitude.
In the cockpit voice recorder, one of the pilots was “heard asking the other why did he cutoff,” and “the other pilot responded that he did not do so.”
So anyway, one big question has been whether a human actually manually moved these switches, or whether there was some horrible technical or mechanical failure that somehow caused the switches to move positions.
While the AAIB has been leading the investigation, the FAA has been providing technical support, so is always aware of the details of the investigation. When there was talk of something involving the fuel control switches, some people pointed out a December 2018 Special Airworthiness Information Bulletin (SAIB), regarding potential disengagement of the fuel control switch locking feature on Boeing 737s, based on reports that the fuel control switches were installed with the locking feature disengaged.
However, that doesn’t appear to be the case here. Per the document:
Although the fuel control switch design, including the locking feature, is similar on various Boeing airplane models, the FAA does not consider this issue to be an unsafe condition that would warrant an Airworthiness Directive on any Boeing airplane models, including the Boeing 787.
In other words, the FAA seems confident that the fuel control switches as such are safe. I don’t think that’s terribly surprising, though it really only leaves one other explanation…
Why did a human move the fuel control switches?
With the FAA essentially confirming that there’s nothing wrong with the Boeing 787’s fuel control switches, that makes it pretty clear that investigators believe this accident happened because a human moved the switches. The question is, why would a human move the switches to “CUTOFF,” when that was guaranteed to send the plane straight into the ground?
It’s hard to envision a scenario where this was done accidentally, especially just a few seconds after takeoff, during the most critical phase of the flight. I would imagine the information that hasn’t been released yet is probably pretty telling.
As of now, the only thing we know about the conversation between the two pilots is how “in the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff,” and “the other pilot responded that he did not do so.” I think the next interesting details will be:
- What was the conversation before and after that happened?
- Was it the captain or first officer asking that question?
With the first officer being the pilot flying and the captain being the pilot monitoring, the captain would’ve been the one more likely in a position to move these switches without it being super obvious (since the pilot flying is using both hands, initially for the yoke and thrust, and then just for the yoke). That assumes there was no one else in the flight deck (and there’s no mention of anyone else in the flight deck in the preliminary report).
It’s hard to imagine any situation in which this could happen by accident, especially if the (much more experienced) captain was the one who moved the switches…
Bottom line
The FAA has released a memo reassuring airline operators that there are no issues with the Boeing 787 fuel control switches, since those switches are the center of the investigation into Air India’s 787-8 crash. I don’t think this is terribly surprising, but it’s also a good clue that the investigation is likely centered around the human factors here, rather than some horrible design flaw that could impact other flights.
What do you make of this FAA memo, and its implications?
It was obvious when this accident happened that this was an unusual accident and the lack of information compared to other accidents provided "fuel" to the speculation that ensued.
The report -released in the middle of the night at the international deadline for a preliminary report - confirmed what a number of people believed which was that the engines were starved for fuel.
The accident report may never be able to find the person...
It was obvious when this accident happened that this was an unusual accident and the lack of information compared to other accidents provided "fuel" to the speculation that ensued.
The report -released in the middle of the night at the international deadline for a preliminary report - confirmed what a number of people believed which was that the engines were starved for fuel.
The accident report may never be able to find the person that moved them intent but unlike other murder by aircraft/suicide scenarios, the evidence is overwhelming that a human moved the switches.
It is precisely that a human moved the switches that make this case highly problematic for AI given that a final report might not be released for over a year or more.
Findings have already drawn exactly what occured very clearly and unfortunately. The thing is not being able to tell which one did it intentionally. Pretty damning that psychoanalysis evaluations of any kind do not take place for pilots at any level. That along with lives lost is a travesty.
The armchair Serious Incident and Accident investigators continue to thump their stubby fingers against the keyboards. Give it up you-know-nothings, your ramblings only add clicks to the website total.
Says a guy who takes SkyTrax ratings seriously
Not surprising, considering FAA's historic lapses in the Boeing certification during the 737 MAX episode. So i'm not sure if this changes anything in terms of what really happened. Only thing missing was a follow up "Thank you" from Boeing.
Indian nationalists are the most ridiculous people. Grasping at straws, more concerned that Boeing catch the blame than acknowledging the truth and hopefully preventing the same issue from occurring in the future. Contrary to your aim, you actually end up making your country look worse.
Think about this for a moment, how can the PF have his hands on the switches when both of his hands are on the control yoke especially in that particular phase of the flight?!
pretty clearly intentional sabotage, or suicidal mental illness. When someone asks, "did you just turn off our engines" and the person replies "I didn't do that", they're clearly aware of and thinking of the answer already.
How about an article on the crash in London?
CORRECTION …. Anon, please be advised that there was No “Crash in London”.
There was however a fatal crash at Southend Airport yesterday. The airport is about 50 miles outside London.
How do they know the fuel switches were moved? How is the monitoring signal collected for the data boxes? Where is the monitoring signal taken from? Does the monitoring signal actually prove that the switches were physically moved or is it a change in the voltage fed to the fuel pump that has been sensed? There seems to be a great amount of speculation and very little actual detail being provided. The available preliminary report...
How do they know the fuel switches were moved? How is the monitoring signal collected for the data boxes? Where is the monitoring signal taken from? Does the monitoring signal actually prove that the switches were physically moved or is it a change in the voltage fed to the fuel pump that has been sensed? There seems to be a great amount of speculation and very little actual detail being provided. The available preliminary report tell us nothing of substance as to how the fuel starvation was actually caused, other than fuel starvation caused the shutdown of both engines.
@ Vic -- Admittedly there are a lot more questions than answers, but the preliminary report seems crystal clear that the actual switches moved, stating "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."
If investigators weren't sure if the switches were actually a factor here, presumably they would've just stated at what time fuel starvation happened, etc. The...
@ Vic -- Admittedly there are a lot more questions than answers, but the preliminary report seems crystal clear that the actual switches moved, stating "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."
If investigators weren't sure if the switches were actually a factor here, presumably they would've just stated at what time fuel starvation happened, etc. The language being used here is presumably deliberate.
What do you mean there are a lot more questions than answers? As you said, the report makes clear that the switches were moved which starved the engines of fuel and brought down the plane. The only questions left are whether this was intentional or incompetence.
The black box would record the position of and changes in any switch. Thats how they create a timeline of everything that happened, absent video from the cockpit. At the same time, the fuel flow rate would also be recorded to decrease as the valve closes. That double verifies to the investigators that what the cockpit commanded, actually happened.
An accident where this was very relevant was the BA83 (coincidentally also the first hull-loss...
The black box would record the position of and changes in any switch. Thats how they create a timeline of everything that happened, absent video from the cockpit. At the same time, the fuel flow rate would also be recorded to decrease as the valve closes. That double verifies to the investigators that what the cockpit commanded, actually happened.
An accident where this was very relevant was the BA83 (coincidentally also the first hull-loss of 777). This flight luckily had 0 fatalities, but moisture in the fuel lines clogged the system and when the cockpit demanded more thrust, fuel flow sensors showed no increase in flow, thus helping the investigators narrow in on the true cause of the accident.
Could they modified in order to avoid being turned off so easily ?
@ McCaron -- It seems highly unlikely that they were moved by accident, given the process. Are you suggesting that in terms of concerns over a pilot doing so intentionally?
Not necessarily specific to this investigation, but I do think pilot mental health needs to be an increasing area of focus, given the record of major commercial accidents we've seen in the past 15 years or so.
Also to add to Ben, psychological evaluation of pilot is very imperfect, leading to many people who are not mentally competent being up in the air on a daily basis. In Europe, evaluation is only done once a year during medicals and it is very small part of it, basically some general questions about yourself and if you or your family member had suicidal thoughts or occurrences. Most pilots lie even if they had or...
Also to add to Ben, psychological evaluation of pilot is very imperfect, leading to many people who are not mentally competent being up in the air on a daily basis. In Europe, evaluation is only done once a year during medicals and it is very small part of it, basically some general questions about yourself and if you or your family member had suicidal thoughts or occurrences. Most pilots lie even if they had or have episodes of depression or stress in their private life because very likely if you tell the truth, it will lead to your medical license being revoked and the airline putting you on leave. It is weird but that is how it tends to be. So generally it ends up being voluntary actions if a pilot wants to report about any episode of psychological conditions they are going through or their colleagues are going through and many times it does not happen