Simulation of Crashed Boeing 787 Put Focus on a Technical Flaw (msn.com) 64
Investigators of a deadly Boeing 787 crash "are studying possible dual engine failure as a scenario that prevented the Boeing Co. 787 jet from staying airborne," reports Bloomberg:
Pilots from the airline reenacted the doomed aircraft's parameters in a flight simulator, including with the landing gear deployed and the wing flaps retracted, and found those settings alone didn't cause a crash, according to people familiar with the investigation. [Also, analysis of the wreckage "suggests the wing flaps and slats, which help an aircraft increase lift during takeoff, were extended correctly."]
The result, alongside the previous discovery that an emergency-power turbine deployed seconds before impact, has reinforced the focus on a technical failure as one possible cause, said the people, who asked not to be identified discussing nonpublic deliberations... [The turbine deploys "in the case of electrical failure," the article points out, and "was activated before the plane crashed, according to previous findings. That fan helps provide the aircraft with vital power, though it's far too small to generate any lift."]
Pilots who reviewed the footage have pointed to the fact that the landing gear was already partially tilted forward, suggesting the cockpit crew had initiated the retraction sequence of the wheels. At the same time, the landing-gear doors had not opened, which pilots say might mean that the aircraft experienced a loss of power or a hydraulic failure — again pointing to possible issues with the engines that provide the aircraft's electricity.
The result, alongside the previous discovery that an emergency-power turbine deployed seconds before impact, has reinforced the focus on a technical failure as one possible cause, said the people, who asked not to be identified discussing nonpublic deliberations... [The turbine deploys "in the case of electrical failure," the article points out, and "was activated before the plane crashed, according to previous findings. That fan helps provide the aircraft with vital power, though it's far too small to generate any lift."]
Pilots who reviewed the footage have pointed to the fact that the landing gear was already partially tilted forward, suggesting the cockpit crew had initiated the retraction sequence of the wheels. At the same time, the landing-gear doors had not opened, which pilots say might mean that the aircraft experienced a loss of power or a hydraulic failure — again pointing to possible issues with the engines that provide the aircraft's electricity.
"far too small to generate any lift"?? (Score:3)
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Are they implying this little propeller is a backup propulsion device?
Re: "far too small to generate any lift"?? (Score:1)
Sure reads that way:
That fan helps provide the aircraft with vital power, though it's far too small to generate any lift.
A charitable reading might be that the quoted source is trying to dispel that very misapprehension. But the "though" though...
Re: "far too small to generate any lift"?? (Score:2)
Re: "far too small to generate any lift"?? (Score:5, Interesting)
A typical jet turbofan airframe has two engines that each have a generator shaft taking turbine energy and making electrical current. It then has a whole 'nother turbine engine used on the ground and in some other flight legs called the APU; this exhausts out the tail cone usually, and can start engines or provide extra hydraulic power if needed, but is slow to start just like the main engines.
For power loss emergencies, a small spring-loaded fan pops into action super fast, called a Ram Air Turbine or RAT. It can only make enough electrical power to reboot key systems like engine FADECs or avionics, often only on one electrical channel instead of all channels. It's only a turbine, not a thrust-producing fan. It's a pinwheel toy in comparison to the APU and even the APU cannot produce significant thrust.
Re: "far too small to generate any lift"?? (Score:1)
Tfa *was* talking about the RAT. Hence the facepalm: The RAT is a source of drag, not thrust, and this should be obvious to anyone who's done as much as play with a wind-up rubber band airplane as a kid.
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Doesn't the 787 also have a battery for electrical power? I remember that early in its lifetime they had some issues with said battery, and tried to blame the manufacturer.
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Yes. But it does not keep long by itself. So the RAT deploys automatically to not drain that battery fast.
Re: "far too small to generate any lift"?? (Score:5, Insightful)
The whole sentence begins from a false premise. It generates electrical and hydraulic power. Therefore it does not matter what size it is, it is the *opposite* of a lift generator. It is a drag generator that *steals* kinetic energy from the aircraft to turn it into power that can be used to help the pilots choose where to crash.
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Sounds like it. I doubt you can display any lower understanding of things. ChatGPT statement without any human review or terminally dumb human?
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that lil wind power generator's just trying to keep up!
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Bloomberg used to be better than this.
When, like their made-up Chinese backplane "surveillance" components? The Bloomberg writer on this aviation piece was an inexcusably ignorant idiot. Bloomberg does at least supply a target-rich environment for sniping.
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Most Americans barely read at a sixth grade level so you better know you audience.
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Most of those Americans with a sixth grade reading level choose not to read anyway. It's a fair choice. (It's also an overstatement. When I write marketing copy, it's to an eighth grade audience if I want to hit the mainstream.)
But to quote Egon in Ghostbusters, "Print is dead." Really. It is. It just took a few decades.
I had a discussion about it with my tenured professor wife, who thinks that civil society is collapsing because people do not have high-value information due to lack of reading. She also bla
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I strongly disagree on the importance of reading. The Druids made the same arguments against the intellectual laziness writing things down engendered, but both the Greeks and the Druids were subjugated by the text-heavy Romans. Text transmits information with higher fidelity and more speedily than speech.
Charges of elitism sound Idiocracy-esque to me. If you want to be embarrassed about modern civilization, read an average American newspaper circa 1850.
Making excuses for illiterac
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I'm sick of the "people don't know how to read, and should read more" argument. It's elitism.
I am more elite than people who don't know how to read.
Re: "far too small to generate any lift"?? (Score:1)
Was at a 4th of july party in one of the "elite" towns outside of Boston where every household has several postgraduate degrees hanging on their walls and shops at whole foods without even looking at the prices.
Ended up in a conversation with one of these supposed high information elitists regarding the content of a (supposedly) grass roots environmentalist campaign to stop the construction of new aircraft hangers at hanscom field. Dude saw the signs but had no idea what the project was about, why the treeh
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Ended up in a conversation with one of these supposed high information elitists regarding the content of a (supposedly) grass roots environmentalist campaign to stop the construction of new aircraft hangers at hanscom field. Dude saw the signs but had no idea what the project was about, why the treehuggers hate it, that the treehuggers are the ones distributing the signs (as opposed to people who merely don't like living under the approach path to an active airfield), or what the status of the project was.
I have no idea what you are trying to say with this anecdote.
Re: "far too small to generate any lift"?? (Score:1)
I said it: elitism is illusory.
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I had a discussion about it with my tenured professor wife, who thinks that civil society is collapsing because people do not have high-value information due to lack of reading. She also blames a lack of basic literacy for many other historical problems. If only those people read, they wouldn't have had that problem.
I was about to quibble with that by pointing out that many oral cultures seem more sensible than our literacy-based one. But I decided to do a bit of research before shooting off my keyboard, and I'm glad that I did:
https://newlearningonline.com/literacies/chapter-1/ong-on-the-differences-between-orality-and-literacy
Basically, oral cultures and literate ones are so profoundly different from each other that the comparison I was about to make is meaningless. I'm embarrassed that it hadn't occurred to me.
Frankly, all of us smarty pantses need to suck it up and get on YouTube or Tik Tok if we want a high information society... Aristotle literally railed against the written word's detrimental effect on people's memory. It's possible to have a high information society without the written word.
I wo
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You should never, ever see the Emergency Power Turbine deployed; if you do it means that Something Really Bad® has happened and the airplane is very likely in the process of crashing.
And yes, Bloomberg absolutely implied that it generates lift, which is the exact opposite of what they do; EPTs actually create A LOT of drag which is bad for any plane that's in a situation where they have to deploy it.
It's a double-edged sword in that it may bring vital systems back online but at the same time it reduces
Re: "far too small to generate any lift"?? (Score:3)
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Which is why the Jeju 737 didnt record any data once its engines shut down - the 737 didnt have a RAT.
Which means that the most important points of the accident were unrecorded.
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According to @StigAviation in a comment at a Blancolirio video on YouTube there are several reasons for the RAT to deploy, none of them are good. [youtube.com]
There’s actually more conditions
Here’s the full list.
Loss of all engines
Both engines are at less than minimum idle RPM (Revolutions Per Minute)
Loss of all hydraulic power - left, right, and center systems detect low pressure
Loss of all electrical power
BPCU (Bus Power Control Unit) detects loss of power to C1 and C2 TRU (Transformer Rectifier Unit)s
On approach, loss of all four EMP (Electric Motor Pump) hydraulic pressures and loss of either the left or right flight controls ACE (Actuator Control Electronics)
Rotor burst on takeoff that causes loss of both PECS (Power Electronics Cooling System) primary cooling loops.
I have also seen that mechanics doing maintenance on the plane need to take precautions for it to not be deployed in case they test the system, but that's when it's on the ground and if it deploys it could hit someone in the head and that wouldn't be good.
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Yep. Somebody there does not even have a minimal clue how things work.
Really? (Score:2)
Most crashes come from a "scenario that prevent a jet from staying airborne."
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TFS for this:
Crashes are caused by physics.
Re: Really? (Score:2)
Above a certain speed and runway position, takeoffs are mandatory too.
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Probably AI slop. Jalopnik is like that now. What articles that aren't AI are just the results from a question they asked the readers a few days prior. Like hey everyone what car has the best tail lights?
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You know what else often comes from a "scenario that prevents a jet from staying airborne"? Emergency landings! Not in this case though. But they are still part of the same set.
Black box? (Score:5, Insightful)
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The mole is only sure of one thing: investigators went in a flight simulator and asked for this and that. The mole is not aware of the full state of the investigation.
We can start speculating why the investigators tested this hypothesis. I agree with you "this is interesting" and I find this explanation sufficient for crash investigators to want to double check all possible scenarios, and see to what extent the particular configuration of the plane contributed to the crash events. Would have they gotten mor
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Not necessarily, it is possible a total power failure took out both the FDR and CVR which leaves investigators with data only up to the failure point, and if that's the case it makes sense to simulate what happened afterwards to see if the plane was recoverable.
I should mentions that all modern passenger planes have redundant electrical systems and the RAT will deploy automatically it if there's a total power failure. There have been a few examples of planes that have had total power failures that managed t
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Today's FDR and CVR boxes are equipped with 10 minute backup batteries. If the batteries did their job then that won;t be an issue. Unless, of course, no data was being sent to them due to a catastrophic failure. My hunch is that this will probably boil down to a software issue with the plane. If it turns out to be software then Boeing needs to be shut down and executives finally held accountable for the murders going on during their watch.
Re: Black box? (Score:2)
God damn Greenpeace! If they hadn't interfered with seal-clubbing, there wouldn't be all these seals causing air crashes! It is political correctness gone mad.
Modern design (Score:4, Interesting)
IIRC the Dreamliner uses a combination Flight Data Recorder and Cockpit Voice Recorder and simply carries two copies of this all-digital combined "black box" (one under the cockpit, and one near the tail). As a result, only one black box needed to be found intact, which India did immediately after the crash. They did not send these to the American NTSB or Boeing and instead moved them to an Indian government lab to extract and process the data themselves.
Either the Indian investigators did not like what they found (it implicated the crew, ground personnel, airline, etc rather than the plane maker) or they were unable to understand the data and were not willing to admit this and hand the boxes over to the experts.
Why would I presume this?
Simple. They've announced the recovery of both boxes, so we know they have all the flight data and voice recordings. If there were data recorded to indicate a problem with the design or construction of the plane, there would have been immediate notifications to the American and European air safety agencies and the plane manufacturer, which would have been followed by airworthiness notifications and possibly groundings. When there's a known safety issue with the design of an airliner, the various safety agencies are not just gonna sit there on their collective hands.
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I doubt it has anything to do with the "not liking" what they found. More likely it is some kind of human error and they are making sure they understand it fully before publishing a report.
The black box recordings usually don't give a complete picture of exactly what went wrong. They can hear the pilots talking, but not what they were thinking. It doesn't have a stress monitor or video of the cockpit, all of that stuff has to be inferred from audio and control inputs. They will want to understand what was h
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The thing is that we do not have statements about what is on the recordings. Take into account that a double engine-failure on takeoff is about the worst thing possible and then think about what that might mean for Boeing, and things become political.
Also crash investigations always use multiple approaches when things look surprising. As they do here.
Fuel or electrical? (Score:3)
Two theories that seem reasonable from what I've been hearing:
1. Contaminated fuel combined with high temps causing the fuel to become gaseous before getting to the engine.
2. Apparently a solar storm hit exactly at the time of the crash, raising questions about induced currents causing an electrical failure.
The emergency turbine shouldn't have deployed if it were bad gas, so that leads to the sudden electrical failure causing the crash.
That turbine works fine at altitude but not at take-off because at least you can glide to a landing if you have electrical/hydraulic power.
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Contaminated fuel isn't totally impossible but is highly unlikely since no other planes had an issue that day, and even with contaminated fuel the odds of the two engines shutting down so close together are quite low. The theory of the jet fuel being contaminated with avgas is also pretty much impossible at a big commercial airport like the one this jet took off from.
Something weird may have caused an electrical or electronic failure that took out both engines at once. Highly unlikely again but not impossib
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This is unlikely because its been shown that the time it takes to go through the 787 engine-out checklist, t
checklists in emergencies (Score:3)
A properly trained and responsible air crew should know what to do in both single-engine and dual-engine failures on takeoff (when there's no time to crack open the owner's manual) and should have practiced this a few times in the sims. The captain and first officer should have talked about their plans for those possibilities before they got clearance to take off; that's proper cockpit resource management. This (understanding the specifics of a make and model of plane) is part of why pilots get certified to
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The fuel intended for a prop plane with an old-fashioned gas engine is avgas, which at this kind of airport would be an oddball fuel that comes from what looks like ordinary gas station pumps in an out-of-the-way area. It would be completely out of the fuel trucks' workflow.
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The sheer difference in quantity of fuel there is going to raise eyebrows if you try and put AvGas into an aircraft that requires JetA.
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I don't think anyone is suggesting it was 100% Avgas. Just that a fuelling tanker had been accidentally part loaded with the wrong stuff, and no one admitted the error.
There are numerous other substances that might have contaminated they fuel and restricted flow - possibly metal objects where they shouldn't have been, oily rags, etc.
I think it will turn out to be fuel related in some way
Wrong fuel would be deliberate sabotage (Score:2)
Jet fuel is a refined kerosene. AvGas is a high octane gasoline. They look different (different colored liquids), smell different, and are dispensed from very different sources at a typical airfield. An individual (a really dumb one) MIGHT make this error on his own at a small airfield, putting fuel into a his general aviation aircraft improperly (putting avgas into, for example, a King Air) but no professional crew that services large multi-engine passenger or cargo jets at a large commercial field could.
I
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Sure about that? Jet engines hypothetically can use anything that burns as fuel, from vegetable oil to coal dust. They generally use kerosene because it is cheap and relatively safe to handle.
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Jet engines hypothetically can use anything that burns as fuel
If designed for that and adjusted for it. The fueling rate has to be correct.
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The emergency turbine shouldn't have deployed if it were bad gas
Where are you getting that from? The purpose of a RAT is to sustain power. It will deploy automatically under a variety of conditions, including dual engine failure on takeoff.
All this bit of spin tells us is that the aircraft wasn't grossly misconfigured by the crew. Great.
This is going to be bad fuel. But that won't come out for a long time, because it will put the fault on a state operated airline, from a state operated airport, investigated by that state's authority. If India could plausibly pi
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If it's bad fuel then other aircraft at the airport would have the same problem. And there appear to be none that have had that problem.
The RAT deploys if there's one of dual engine failure, electrical failure, hydraulic failure. And it won't supply full electric power.
Wait for the authorities to report. They want to get it right first time.
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2. Apparently a solar storm hit exactly at the time of the crash, raising questions about induced currents causing an electrical failure.
That only raises questions for people who have no idea how things work. If this were the case planes would have fallen out of the high sky rather than the ones close to the ground. We would have seen that everywhere, blips and problems would have been recorded over a wide area.
I am putting that one in the safe "conspiracy theory" box. There's a million things which could cause technical failure that are more likely than a solar storm affecting one and only one aircraft.
So, full engine failure on takeoff? (Score:2)
It can hardly get any worse than that. Unless this is a freak accident, looks like Boeing is really done for, even if the plane was 11 years old.
Watch Captain Steeeve (Score:2)
Wow... (Score:2)
"...that prevented the aircraft from staying airborne."
That's a (much too) pretty way to say it crashed.