Hey Juan, really enjoy your reporting. I'm a career engineer here at P&W in East Hartford. Dialed in to a zoom call with out President (Chris Calio) today and he stated all Hollow Fan Blade segments have been recovered and are in our lab in East Hartford. Just passing this along, thanks.
An explanation I heard was that hydraulic fluid or oil is present in that area. The significant internal failure of the engine may have ruptured some pipes and the engine is consuming those fluids.
However I don't know if the engines have independent hydraulic fluid supplies for the thrust reverser and any other actuators, because I don't recall the pilots reporting a hydraulics failure.
how does it stay burning at 600mph? it must be either very flammable, very hot or pilot lighted by something
is the engine like still sustaining itself by oil dripping into the middle and igniting and the flame being pushed out to make it look like its on fire on the outside despite the outside not burning? i.e. combustion occurs in the same place as it does with the fuel but instead occurs with residual oils but the amount of fire is excessive so it gets pushed out, operating kinda like a reflux condenser, in terms of liquid being sucked into the middle then fire being pushed out, not in the sense of condensation?
how does it stay burning at 600mph? it must be either very flammable, very hot or pilot lighted by something
is the engine like still sustaining itself by oil dripping into the middle and igniting and the flame being pushed out to make it look like its on fire on the outside despite the outside not burning? i.e. combustion occurs in the same place as it does with the fuel but instead occurs with residual oils but the amount of fire is excessive so it gets pushed out, operating kinda like a reflux condenser, in terms of liquid being sucked into the middle then fire being pushed out, not in the sense of condensation?
The aircraft isn't travelling at 600mph, nor is its indicated airspeed (which would represent how much the fire 'feels' the air) 600mph. They would've been at an IAS of about 280kts or 322mph. Ground speed would have been somewhat higher, maybe 320kts. They were fairly low in the climb, not at altitude in cruise.
Where you see the fire emanating from is the thrust reverser 'translating sleeve' with many vanes to redirect the air to the rear. The thrust reverser doors appear to be closed, so no significant airflow from the fan duct (or fuel or anything else from the engine core) can reach this area in this configuration. Since the purpose of these vanes is to direct air rearward, the pockets are 'out of the wind' so to speak, and yeah maybe there is an element of negative pressure helping to suck fuel from whatever the fuel source is. From the reports so far, it doesn't sound like there were any major fuel leaks and the fuel shutoffs worked as designed, so I'd guess this is either residual fuel from ruptured lines or hydraulic oil, possibly from the TR mechanism itself, but could be anything mounted on the outside of the engine. This will be a focus of the investigation for sure.
It's definitely not that you're seeing combustion in the core, the TR doors are closed, and even if they were open, you'd only see inside the fan duct, not the core. Any flame you might observe (extremely unlikely) inside the combustion chambers due to catastrophic damage would be much deeper inside the engine than is observed here which is clearly near the surface. If that were happening, you'd probably see it inside the fan duct as well from the front/rear.
Thrust from this would be negligible, it's clearly not a very significant amount of fire, and it's happening in 'free air'.
isent it up to boeing to analyze the engine to make sure its good? They vet the subassembly after all. It will be complicated to figure out whos fault it is
i.e.
lack of maintenance
incorrect maintenance
bad from factory
1) design flaw
2) manufacturing defect (QC fail)
installed incorrectly/damaged during installation
system interfaced incorrectly (the engine has I/O), or its just not compatible with the design for whatever mechanical reason, if its not related to hydraulics or electronics or telemetry
failed to inspect device before/after installation
failed to perform more stringent tests
control safety system fail (did not monitor telemetry or handwaving was involved)
of course its up to the investigators to find out what happened
isent it up to boeing to analyze the engine to make sure its good? They vet the subassembly after all. It will be complicated to figure out whos fault it is
i.e.
lack of maintenance
incorrect maintenance
bad from factory
1) design flaw
2) manufacturing defect (QC fail)
installed incorrectly/damaged during installation
system interfaced incorrectly (the engine has I/O), or its just not compatible with the design for whatever mechanical reason, if its not related to hydraulics or electronics or telemetry
failed to inspect device before/after installation
failed to perform more stringent tests
control safety system fail (did not monitor telemetry or handwaving was involved)
of course its up to the investigators to find out what happened
Oh, for crying out loud - no, it's NOT Boeing at fault here. Maybe some maintenance procedures - but they would not have originated from Boeing responsible components.
Oh, for crying out loud - no, it's NOT Boeing at fault here. Maybe some maintenance procedures - but they would not have originated from Boeing responsible components.If my TV breaks I wouldn't say "Its not LG's fault. They didn't make the component that broke.". Anyone integrating parts into a product is responsible for the whole product.
Oh, for crying out loud - no, it's NOT Boeing at fault here. Maybe some maintenance procedures - but they would not have originated from Boeing responsible components.If my TV breaks I wouldn't say "Its not LG's fault. They didn't make the component that broke.". Anyone integrating parts into a product is responsible for the whole product.
If my TV breaks I wouldn't say "Its not LG's fault. They didn't make the component that broke.". Anyone integrating parts into a product is responsible for the whole product.
so the explanation I read in this thread makes me think the profession I took is way too complicated because it seems easier to pick a plane engine then a damn single resistor. I can't even do that. I can still fuck a resistor choice in a way that they will blame me.
Airbus = Awesome
AF447.
The plane had flown under 3,000 cycles which is less than half before blade inspection is due at 6,500 cycles. It seems like a very long time between inspections. That engine has bigger, fewer turbine blades, hollow so maybe they pushed the tech too far and gave unicorn and rainbow inspection frequency to make the engines seem cheaper to maintain.
Airbus = Awesome
AF447.
If ever there were an accident where it was appropriate to say 'it was completely pilot error', this is it. There's always blame to go around, and there were some HMI problems identified with the Airbus flight controls, but you really can't blame the airframe or control systems for a pilot continually doing the opposite of what they were trained to do and the procedures say to do for multiple minutes while they fly the plane into the sea. The pilots still have mostly ultimate authority, and if what they are actively doing is going to crash the plane, with the exception of alpha-prot, the airframe isn't going to stop them.
I attribute a degree of blame to Airbus because the pilots (neither particularly good, clearly) were unable to accept they were in a stall because it's an Airbus, and it won't let you stall. Except when it does.
And yes, it was pilot error. Like most pilot errors, there are contributing factors.
I attribute a degree of blame to Airbus because the pilots (neither particularly good, clearly) were unable to accept they were in a stall because it's an Airbus, and it won't let you stall. Except when it does.
And yes, it was pilot error. Like most pilot errors, there are contributing factors.
Usually I'm with you on there being multiple critical factors to blame, I just don't really think that was the case in this accident to the degree it usually is. They identified the unreliable airspeed early on, and understood it later in the sequence, yet never completed the associated procedure nor were their control responses appropriate for that condition. They didn't discuss the stall alarms at all, which is pretty strange, but doesn't lead to the conclusion that they thought they could ignore the continuous stall alarm because they were in normal law; they also called out the shift to alternate law, though I agree it could have easily been missed. There's no excuse for not executing the stall recovery procedure (or even earlier, the unreliable airspeed procedure - some of the items were performed but it was not done in the expected challenge/response systematic manner, nor completed), nor for the PNF to continually provide control inputs after giving the controls to the Captain - or this was a CRM failure where they had conflicting interpretations of who was in control, but regardless it is a piloting issue.
Confusion in complex failures is a relatively common cause of accidents, and I'm usually the first to defend the pilots in a situation with conflicting alarms and information, but in this case the only alarm they were getting initially was STALL STALL, and their conditioned response to that should be to execute a stall recovery or if they were actually looking at their PFD, maybe unusual attitude recovery could be justified. And the only unreliable indication they were receiving was airspeed, which recovered shortly after the incident began. It appears they just completely ignored the attitude indicator they should have known they could trust, as well as the repeated stall warnings. Suspecting unreliable airspeed seems to have led them to mistrust the airplane entirely and ignore everything else it was telling them, and that's not defensible, especially in hard IMC.
The only places where the aircraft could arguably have done a better job IMO would be not suppressing the stall alarm below 60KIAS, and kicking the flight directors completely off when the data was invalid, rather than restoring them as the data came back, but by the time the incident evolved that far, they should have already executed the stall recovery procedure. Even after it did get that far, getting out of stall and back to a normal attitude should be overriding anything else in their minds. Regardless of anything else, including airspeed which was suspect, it would have been obvious they were at an extreme nose up attitude that would lead to stall. You could argue the pilots should have visibility of AoA data, but this isn't unique to Airbus, and they certainly didn't need it to tell them they were stalling the plane, the plane did that all on its own, as would have their attitude indicator.
The BEA didn't request any changes to the airplane as a result of the accident, and I think that's pretty clear indication they don't think any part of it was causal here. It's just bad pilot decision making from the Captain's laissez faire attitude about the weather, to not executing the unreliable airspeed procedure, to ignoring the stall warnings, to applying inappropriate control inputs, to continuing to apply those inputs after the Captain ostensibly took control.
Anyway, apologies for dragging this off topic, just get tired of people bringing up AF447 as if it's clearly the fault of Airbus; even with the most generous interpretation, the airplane plays a minor part in this accident.
Anyway, apologies for dragging this off topic, just get tired of people bringing up AF447 as if it's clearly the fault of Airbus; even with the most generous interpretation, the airplane plays a minor part in this accident.
The problem I have with the Airbus design with its decoupled side sticks is perfectly illustrated in this incident - the pilot flying is mistaken, and is inputting full nose up on his control stick. The guy on the other side of the cockpit doesn't realize this, because he can push his stick full forward independently. The aural warning says something about the mixed control inputs, but that can be missed in the confusion. Boeing's control columns are coupled together - the guy in the right seat is going to know what the guy in the left seat is doing, because his control wheel moves in unison. From what I've read of that accident, it seems that at times the left seater was trying to lower the nose, but the right seater had control authority and so it stayed up. There'd have been no question how the controls were positioned in a Boeing craft, as BOTH the yokes would have been pulled back, and you can FEEL if the guy next to you is fighting you on the controls. Seems to be a fundamental design flaw in the controls that can rise up under confusing/stressful situations to bite you hard in the ass, permitting erroneous control inputs where one side has no idea what the other is doing, as we saw here.