Merged Major aircrash in Ahmedabad, India / India plane crash. First 787 to crash

SpitfireIX said:
There are a number of scenarios where contamination could affect only one aircraft. I couldn't find out for sure whether Ahmedabad uses a hydrant system, but even if they do, fuel trucks would still be used in some cases (usually not all parking positions have hydrants, and hydrants will occasionally be out of service). So, theoretically, there could be a problem with just one truckload. Also, some hydrocarbon-soluble foreign object could get into the system and then disintegrate once it gets into the plane's tanks (that would require multiple colossal screw-ups, but the chance isn't zero). And, sadly, there's always the possibility of an intentional act. It would definitely be possible with the aforementioned truck, and enough contaminants.
Click to expand...

OK, well in favour of your point, I read somewhere (can't remember exactly where, sorry) that Ahmedabad airport (Sardar Vallabhbhai Patel International Airport) has recently finished a major project including new stands, new sky-bridges and an upgraded fuel delivery system, so that is probably underground tanks with hydrants and pumping trucks. You will know more about this than me with your experience in the industry, but IIRC from years back when the Air Force Base I was at did something similar, one of the things that needed to be done wast to flush out all the pipes, pumps and hydrants.

But I still go back to the other point, that fuel contamination, at least in jet fuel, requires considerable time (measured in hours) to do enough damage to an engine to cause it to shut down, and over that period of time, there will be obvious signs of something being wrong. I do have some experience with fuel contamination (Lockheed C-130, Lockheed P3C and Boeing 727). In my experience, the level of contamination required to shut down two engines that quickly, and at the same time, would be so high that I find it hard to beleive it would go unnoticed during engine start-up. I have been in the cockpit of a C-130 Hercules (admittedly a turboprop not a turbojet, but the principle is the same) when it started up with contaminated fuel. There were two obvious signs from the get-go that something was wrong

1. The engine wound up to a much higher RPM than usual before ignition. Usually it would ignite by about 30-40%.... but in this case, it was well over 60%
2. Once it did ignite, the TIT gauges (Turbine Inlet Temparture) climbed very high, very quickly and past the nominal starting TIT of about 800°C

Also, I don't know about the 787, but I can tell you that an off-nominal start like in any acircaft I worked on would result in a "Stop and Inspect" procedure.

I'm not saying it can't be fuel contamination, just that I can't see how the pilots would not have realized something was seriously wrong long before pushing the TOGA button.
 
The video I speculated about - where I wondered why the photographer started recording - adds nothing new. He was a teenager from out of town and an plane enthusiast. He was recording everything that flew over.
 
smartcooky said:
One fuel system issue that might result in immediate engine shutdown is a vapor lock, but I have only ever hear of it happening on one engine.
Click to expand...
Captain Steeeve has now brought this up. The whole video is interesting, but if you just want to see the discussion about possible fuel-based causes of double engine failure, that begins at time 9:25

 
I would like to point out, again, that the 787 uses EAFR so there are no separate CVR and FDR; both sets of data (and EAFR supports vastly more data inputs than older systems) are recorded to both boxes.
 
This is hard to cut and paste from. RAT did come out.
www.ndtv.com

6 Air India Dreamliner International Flights Cancelled Today

Air India cancelled six international flights - all using the 787-8 Dreamliner - Tuesday amid increased scrutiny of Boeing's flagship aircraft after the horrific crash last week in Ahmedabad.
www.ndtv.com www.ndtv.com
RAT:
This only happens when there is dual engine or a system-wide electronic or hydraulic failure, experts have told NDTV. However, what caused this failure is still an unknown.
Click to expand...
 
catsmate said:
I would like to point out, again, that the 787 uses EAFR so there are no separate CVR and FDR; both sets of data (and EAFR supports vastly more data inputs than older systems) are recorded to both boxes.
Click to expand...
Actually 787s have two EAFRs, one in the tail section, the other in the nose section.
 
JayUtah said:
I normally respect "Captain Steve," but the notion that a 787 pilot would mistake the flaps control for the landing gear control is like saying you meant to stab a piece of your steak on your plate with your fork and stabbed yourself in the eye instead. The flaps control is on the pedestal, where it has been on every major airframe for the past 100 years. The landing gear control is a lever in the instrument panel, where it has been for the past 100 years. "Captain Steve" can get bent.
Click to expand...

I don't know what evidence Captain Steve was going by. For my own part, I held that view briefly, between one post and my next, based on early evidence that was a subset of what was generally disseminated just a day or two later. What it looked like was, the plane had lift and then it didn't have lift, and meanwhile the landing gear that should have been raised beginning at that moment wasn't raised, and (everyone discussing the issue was saying) dual engine failure was overwhelmingly unlikely especially with no visible flame or smoke. Also, there was chatter about lax standards in the airline, and little information at the time about the flight crews' experience.

What became known or more firmly established during that interval includes the deployment of the ram-air turbine, evidence that the flaps were correctly set for the conditions throughout the flight, the pilots' mayday call, and the pilots' flight records, all of which are inconsistent with the oops-wrong-switch hypothesis.

As I mentioned I also, from repeated viewing, decided to trust more in my initial impression that the plane must have lost thrust, not just lift or maneuvering control. Because otherwise it would still have been accelerating (forward) as it dropped.

So now we're looking at dual engine failure after all, with attention focused on the high ambient temperature and the time the plane was waiting idle on the tarmac before departure. Supposedly there was no cabin AC during the wait, but I don't know how much the cabin AC would have affected the temperature of the machinery (i.e. fuel lines) anyhow. What I'm reading is that the fuel pumps (hydraulic) should have been robust enough to prevent or overcome any vapor lock, by brute force. So most vapor lock scenarios seem to be hydraulic failure scenarios, where gravity fuel flow would be a backup but vapor lock prevents that. Still needs a cause for the initial hydraulic or fuel pump failure, but overall that seems like a plausible failure cascade with enough specific circumstances to explain why it hasn't happened before.
 
Myriad said:
I don't know what evidence Captain Steve was going by.
Click to expand...
It's best to point out here in the first sentence that Captain Steve has now abandoned the wrong-switch theory and apologized to the air crew community at large for suggesting it. Apparently he got deservedly roasted. I simply find that hypothesis preposterous on its face, as apparently many others do.

I get that dual engine failure was considered too remote to believe and that loss of lift needed to be explained some other way. And it's tempting in the early stages to fit a narrative that includes both the apparently retracted flaps and the still extended landing gear. But consider technical failure before you insinuate that a pilot did something wrong that's second nature for any experienced pilot across a variety of airframes. Consider local, individual causes and explanations first, before trying to Occam it up into something possibly bigger.

There's literally no reason the gear control in a modern airliner can't be simple buttons that say "wheels go up" and "wheels go down." It remains a little lever with a little wheel on it sticking out of the forward instrument panel because that's what pilots have expected for 100 years, and meshing with their deeply ingrained expectations is a major plus for safety. I just feel I need to explain why I thought the wrong-switch hypothesis was too preposterous to take seriously. The corollary to that, I suppose, is that others found dual engine failure to be equally preposterous and proceeded from there.

Myriad said:
Supposedly there was no cabin AC during the wait, but I don't know how much the cabin AC would have affected the temperature of the machinery...
Click to expand...
Not much, in my gut expectation. I expect the investigation will do a thorough heat transfer study.

Myriad said:
What I'm reading is that the fuel pumps (hydraulic) should have been robust enough to prevent or overcome any vapor lock, by brute force.
Click to expand...
Electric, on the 787. Normally yes, we would expect the pumps (however powered) to maintain enough fuel pressure to prevent vapor lock. A lot of people are appropriately talking about temperature, which was quite hot at the aerodrome. But if the pumps maintain enough pressure then it should keep the fuel liquid throughout all operating regimes. That all depends on the pumps biting into liquid fuel. If the vapor forms in the pump (or reaches the pump), then it stops pumping.
 
Trebuchet said:
Could the fuel system have been incorrectly configured for takeoff somehow?
Click to expand...
I can't imagine any configuration that would let you get off the ground on a normal ascent profile and then starve the engines at 600 ft. You can certainly configure the fuel system so that the engines don't run at all. But something that gives you TOGA thrust up through and beyond V2 and then suddenly produces zero power isn't a configuration I'm aware of. According to the picture of evidence we have now, I'm firmly in the camp of this being a failure of machinery.
 
JayUtah said:
I can't imagine any configuration that would let you get off the ground on a normal ascent profile and then starve the engines at 600 ft. You can certainly configure the fuel system so that the engines don't run at all. But something that gives you TOGA thrust up through and beyond V2 and then suddenly produces zero power isn't a configuration I'm aware of. According to the picture of evidence we have now, I'm firmly in the camp of this being a failure of machinery.
Click to expand...
Thanks, not my area of expertise. Sounds like not good news for Boeing. Again.
 
Only "normal" i.e. non-failure way I can think of is to deliberately pull the throttles all the way back to idle. But that would probably be overridden by the computers, and involve multiple very loud warnings. Plus that would probably not deploy the RAT and APU, nor involve electrical failures.
 
Norman Alexander said:
Only "normal" i.e. non-failure way I can think of is to deliberately pull the throttles all the way back to idle. But that would probably be overridden by the computers, and involve multiple very loud warnings.
Click to expand...
The engines are under FADEC control. I see someone has posted a video offering a relevant hypothesis to that, which I haven't yet seen. But yes, accidentally overriding the autothrottle that's commanding TAGO (i.e., fulll thrust) produces a kind of Star Trek red-alert sound on a Boeing. You can defeat that, however, by manually pressing the autothrottle disconnect button that's under your thumb when you hold the thrust levers (either pilot).

Norman Alexander said:
Plus that would probably not deploy the RAT and APU, nor involve electrical failures.
Click to expand...
Correct. Even at ground-idle (the lowest selectable thrust level) you still have the accessory drive train running. You'll have a little bit of thrust, but full AC power and full hydraulic power. There's a constant-speed drive on the generators. And while this is particularly important on the mostly-electric 787, the engine control parameters will be the same for any major modern airframe and engine.

The only way to fully shut down the engines is to switch of the fuel feed (switches behind the throttles) or to pull the fire handle for an engine.

Trebuchet said:
Thanks, not my area of expertise. Sounds like not good news for Boeing. Again.
Click to expand...
Indeed. But the 787 was designed by the last vestiges of the legendary Boeing design teams, before the McDonnell Douglas rot had fully set in. The fact that they went 15 years before a full-airframe loss is a testament to the 787's robust design, even if current Boeing is way off in the weeds.

My brother-in-law is an engineer at Boeing. He works on the 777X. I talked to him yesterday. They're not really doing well there this weekend.
 
JayUtah said:
The engines are under FADEC control. I see someone has posted a video offering a relevant hypothesis to that, which I haven't yet seen.
Click to expand...
In that video, the person talks about a FADEC fault happening the moment the "Weight-on-Wheels" sensors are triggered, i.e., the moment when the aircraft gets airborne (presumably intertia keeping the speed high enough to climb until it falls off and reduces lift to near stalling point).
I find it hard to imagine what sort of fault could cause that to happen. Given that each engine has its own FADEC, and that each is powered by its own dedicated alternator, an electrical failure does not cause the engines to shut down.
 
Last edited:
smartcooky said:
In that video, the person talks about a FADEC fault happening the moment the "Weight-on-Wheels" sensors are triggered...
Click to expand...
Thanks; I do plan to watch the video. I'm just behind, and exhausted.

smartcooky said:
I find it hard to imagine what sort of fault could cause that to happen. Given that each engine has its own FADEC, and that each is powered by its own dedicated alternator, an electrical failure does not cause the engines to shut down.
Click to expand...
Correct. The 787 electrical system is a bit byzantine, so I'll have to watch the video carefully to make sure I understand its claim. But no, electrical failure does not cause engine shutdown.
 
smartcooky said:
In that video, the person talks about a FADEC fault happening the moment the "Weight-on-Wheels" sensors are triggered, i.e., the moment when the aircraft gets airborne (presumably intertia keeping the speed high enough to climb until it falls off and reduces lift to near stalling point).
I find it hard to imagine what sort of fault could cause that to happen.
Given that each engine has its own FADEC, and that each is powered by its own dedicated alternator, an electrical failure does not cause the engines to shut down.
Click to expand...
That would seem to rule this explanation out. Unless, by some considerable bad luck, there was a simultaneous failure.
 
JayUtah said:
(snip)


Indeed. But the 787 was designed by the last vestiges of the legendary Boeing design teams, before the McDonnell Douglas rot had fully set in. The fact that they went 15 years before a full-airframe loss is a testament to the 787's robust design, even if current Boeing is way off in the weeds.

My brother-in-law is an engineer at Boeing. He works on the 777X. I talked to him yesterday. They're not really doing well there this weekend.
Click to expand...
As an engineer there at the time, I can assure you that the rot had VERY thoroughly set in by the time the 787 came along! We had, after all, gone on strike for forty days (and forty nights) in early 2000 basically over the McD management practices, which were really Jack Welch management practices. (I say McD only because McDonnell management practices destroyed Douglas Aircraft even more thoroughly than they have since ruined Boeing.)
Regarding the 787 in particular, the entire philosphy seemed to be that every job except upper management should be done by someone else's employees. Senior management had long considered all Boeing employees to be the enemy. Everything was outsourced if at all possible. Including to your company, Jay. Some, probably including yours, were up to the task. Others weren't.
I once sat in a large meeting where a senior manager ranted that Boeing's "core competency" was "large scale systems integration", and that by no means should the company be designing brackets. He went on and on about brackets.
When the 787 rolled out it was an empty shell. Because there was no way to integrate all those outsourced systems into the airframe. You need, guess what, a great many brackets to do this. No one had planned to get them designed.
 
Trebuchet said:
As an engineer there at the time, I can assure you that the rot had VERY thoroughly set in by the time the 787 came along!
Click to expand...
I'll defer to your closer perspective, then. The impression I got as a contractor was that things got dramatically worse after our work on the 787, but there are probably reasons why it seemed that way.

Trebuchet said:
Senior management had long considered all Boeing employees to be the enemy.
Click to expand...
I saw evidence of that in my work. In my experience, the employees were interested in quality and safety while management was hyper fixated on schedules and budgets. More than once I got side-chatted by Boeing employees who said things like, "Take however long you need, just don't give me something that doesn't work."

Trebuchet said:
Everything was outsourced if at all possible. Including to your company, Jay. Some, probably including yours, were up to the task. Others weren't.
Click to expand...
No doubt. The elements that would later become the core of my company had been contracting for Boeing since the 777. So it was unlikely that we wouldn't have won the contract for that particular niche on the 787. However, we did a lot more service-oriented work on the 787 which could have been done by Boeing people. We were happy to get the work back then. However, at present we have elected to pursue no more new contracts with Boeing.
 
JayUtah said:
Forgive me, this is not a good weekend for me.

My company built its reputation on the work we did for Boeing on the computational dynamics for the Boeing 787 wing and airframe. This is the first loss of a full airframe for this design. We're taking it very hard. At the same time, at Boeing's request, we have spent the last 72 hours resurrecting 15-year-old computer models in case they will be needed for the investigation.

Then there was a fatal shooting at a march I would have attended but for this emergency.

I don't think I'll be involved directly in the investigation. So I can comment for now, but there may come a time when I have to recuse myself.

A couple of points. Yes, the flaps were down. The flaps on the 787 are markedly different than previous airframes that used the traditional Fowler design. The upper surface of the flaps is meant to conform closely to the wing body's trailing edge. The people who are telling you the flaps weren't set right are trying to transfer their knowledge from other less relevant airframes.

I normally respect "Captain Steve," but the notion that a 787 pilot would mistake the flaps control for the landing gear control is like saying you meant to stab a piece of your steak on your plate with your fork and stabbed yourself in the eye instead. The flaps control is on the pedestal, where it has been on every major airframe for the past 100 years. The landing gear control is a lever in the instrument panel, where it has been for the past 100 years. "Captain Steve" can get bent.

I'm exhausted. I'm only now catching up on the frenzy of speculation.
Click to expand...
TBF, Captain Steve has said he was completely wrong, and his first video he mentioned repeatedly it was just conjecture.

Very odd, I found his channel about 2 weeks before the crash, and now its blown up. YT figured out I liked FS2024 videos and recommended his channel.
 
lobosrul5 said:
TBF, Captain Steve has said he was completely wrong, and his first video he mentioned repeatedly it was just conjecture.
Click to expand...
And TBF I acknowledged his retraction in post #131. At that stage everything was conjecture. But there's responsible conjecture and then there's just bonkers. It's an overall good channel, and I recommend it. But that one particular thing wasn't a hypothesis I think he should have made while wearing a captain's uniform.
 
I've had a rethink about the vapour lock theory.

Despite the fact that vapour lock is a fuel feed system issue, and fuel is one of the things capable is stopping an engine that is common to both engines, I struggle to see how it could happen to both at once. The engines are started one at a time (on the 787, No. 2 first, then No. 1 IIRC). It is clear they lost thrust on both engines at near the exact same time... (otherwise the asymmetric thrust from having only the single working engine would cause an immediate yaw towards the side of the failed engine).

In regards to the landing gear, that is retracted as soon as a positive climb rate is achieved, which would usually be immediately after "V2 - rotate" and it is apparent from the downward pointing position of the main gear bogies, that gear up was selected right at the time that whatever happened, happened.
 
There are just endless videos to watch to understand a jet engine and how it is supplied with air and fuel. I will be looking to see for what the procedure is to get an engine back on, when an engine goes out in a regular flight. There are I think two flights that had a 787 finishing a trip with one engine.
 
Myriad said:
I don't know what evidence Captain Steve was going by. For my own part, I held that view briefly, between one post and my next, based on early evidence that was a subset of what was generally disseminated just a day or two later. What it looked like was, the plane had lift and then it didn't have lift, and meanwhile the landing gear that should have been raised beginning at that moment wasn't raised, and (everyone discussing the issue was saying) dual engine failure was overwhelmingly unlikely especially with no visible flame or smoke. Also, there was chatter about lax standards in the airline, and little information at the time about the flight crews' experience.

What became known or more firmly established during that interval includes the deployment of the ram-air turbine, evidence that the flaps were correctly set for the conditions throughout the flight, the pilots' mayday call, and the pilots' flight records, all of which are inconsistent with the oops-wrong-switch hypothesis.

As I mentioned I also, from repeated viewing, decided to trust more in my initial impression that the plane must have lost thrust, not just lift or maneuvering control. Because otherwise it would still have been accelerating (forward) as it dropped.

So now we're looking at dual engine failure after all, with attention focused on the high ambient temperature and the time the plane was waiting idle on the tarmac before departure. Supposedly there was no cabin AC during the wait, but I don't know how much the cabin AC would have affected the temperature of the machinery (i.e. fuel lines) anyhow. What I'm reading is that the fuel pumps (hydraulic) should have been robust enough to prevent or overcome any vapor lock, by brute force. So most vapor lock scenarios seem to be hydraulic failure scenarios, where gravity fuel flow would be a backup but vapor lock prevents that. Still needs a cause for the initial hydraulic or fuel pump failure, but overall that seems like a plausible failure cascade with enough specific circumstances to explain why it hasn't happened before.
Click to expand...
Yeah, about that. If the only reason you are dismissing a potential cause* is that it is "overwhelmingly unlikely", I'm going to need to see a quantified estimate because "overwhelmingly unlikely" on a single take off becomes "more or less inevitable" after enough take offs have occurred. If the chance of a dual engine failure is a million to one (a number I picked out of my arse for illustrative purposes - it must really be much more unlikely) then, given over 100 thousand flights every day, you'd certainly expect one every couple of weeks.

If you've got other more probable scenarios, then I agree: push it down the list but you can't rule it out completely until you have the data that says at least one engine was running normally.

*using "cause" in a loose sense here because the real cause you are interested in is why the engines failed.
 
jeremyp said:
Yeah, about that. If the only reason you are dismissing a potential cause* is that it is "overwhelmingly unlikely", I'm going to need to see a quantified estimate because "overwhelmingly unlikely" on a single take off becomes "more or less inevitable" after enough take offs have occurred.
Click to expand...
The Gambler's Fallacy notwithstanding, when we see the initial signs of an accident that seem to defy ordinary expectation, it's okay to consider that the ultimate narrative might be extraordinary. And sometimes we have to take that medicine ourselves. If the final answer here turns out to be pilot error, then a lot of us will need to go cap in hand to Captain Steve.
 
jeremyp said:
Yeah, about that. If the only reason you are dismissing a potential cause* is that it is "overwhelmingly unlikely", I'm going to need to see a quantified estimate because "overwhelmingly unlikely" on a single take off becomes "more or less inevitable" after enough take offs have occurred. If the chance of a dual engine failure is a million to one (a number I picked out of my arse for illustrative purposes - it must really be much more unlikely) then, given over 100 thousand flights every day, you'd certainly expect one every couple of weeks.

If you've got other more probable scenarios, then I agree: push it down the list but you can't rule it out completely until you have the data that says at least one engine was running normally.

*using "cause" in a loose sense here because the real cause you are interested in is why the engines failed.
Click to expand...

Everyone involved in the conversation understands, and has understood from the start, that "unlikely" (overwhelmingly or otherwise) to be the cause of an event that's already occurred is different from "unlikely" to occur on any given day or any given flight. The commentary I was reading and viewing at the time were all from people who knew the plane had crashed and had examined the (very limited) evidence available at the time, and still opined that dual engine failure was a far less likely scenario for the crash than other possibilities.

No one at any time ruled anything out completely, nor is doing so now. The very post you quoted describes how and why I changed my mind less than a day later, given further evidence and my own further consideration of the what the original evidence was showing.
 
JayUtah said:
The Gambler's Fallacy notwithstanding, when we see the initial signs of an accident that seem to defy ordinary expectation, it's okay to consider that the ultimate narrative might be extraordinary. And sometimes we have to take that medicine ourselves. If the final answer here turns out to be pilot error, then a lot of us will need to go cap in hand to Captain Steve.
Click to expand...
Yes, many things we do with our hands seem to be routine. Yet I can't remember where I put down my glasses. My mower is new and it has two levers. They are not that different from the old mower, but angled. I put some soft padding on one lever, to teach myself that that is the self propelling part as distinguished from hard skinny lever, which cuts power.
 
jeremyp said:
Yeah, about that. If the only reason you are dismissing a potential cause* is that it is "overwhelmingly unlikely",
Click to expand...
I dismiss it as a cause because raising the flaps too early during climb out wouldn't have caused a 787 to fall out of the sky. A fully loaded 787 will successfully rotate and get airborne with flaps fully retracted, and then will still climb out if one engine fails.

I also dismiss it as a cause because it is clear from the mobile phone video that the gear was selected up but did not retract.
(See my post #87)
 
Last edited:
Tero said:
Yes, many things we do with our hands seem to be routine. Yet I can't remember where I put down my glasses. My mower is new and it has two levers. They are not that different from the old mower, but angled. I put some soft padding on one lever, to teach myself that that is the self propelling part as distinguished from hard skinny lever, which cuts power.
Click to expand...
The thing is that your mower just has levers. That is much easier to confuse. The physical actions required to raise the gear and raise the flaps involve differently shaped levers, in different places in the cockpit and most significantly, employ different mechanical actions. It would like changing down a gear in a car while driving stick, when what you really meant to do was indicate a right turn.
 
Last edited:
The first time I drove in the Europe, I did indeed attempt to change gears using the door mounted window winder.
I wasn’t in panic of a crash at the time.
 
EHocking said:
The first time I drove in the Europe, I did indeed attempt to change gears using the door mounted window winder.
I wasn’t in panic of a crash at the time.
Click to expand...
I remember when my dad switched from Ford to Toyota, the indicator/wiper levers were on opposite sides of the column.
 
You must log in or register to reply here.

Back
Top Bottom