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Air France 447 Black Boxes Readable
An anonymous reader writes "It's not a lengthy press release, but it's good news: the memory cards for the flight data and cockpit voice recorders from the Air France 447 crash in 2009, recently recovered from the sea floor almost two years later, are readable. The data was recovered over the weekend and includes the full two hours of cockpit recording. Apparently it will take weeks for analysis of the data, but it looks like the challenging recovery effort is paying off in a big way. Hopefully detailed answers about the cause of the crash will follow."
Tragic story so far, but atleast it shows the viability of solid-state memory. On a sidenote: If there is only 2 hours of voice recording, why will it take weeks to listen to it?
http://www.youtube.com/watch?v=bhk4HcxhZQM
Pilots talk about cheese, the flight attendants ass for 1:59, strange voice yells "alluhu ackbar", tape ends.
So I guess we'll never know what happened!
It was a trap!
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The same as for almost every airplane crash -- gravity.
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Impact Shock 3400G, 6.5 milliseconds
Penetration Resistance 500 lb. weight from 10 feet
Static Crush 5000 lbs., 5 minutes
High Temperature Fire 1100 C, 30 minutes
Low Temperature Fire 260 C, 10 hours
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There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Seems the one part that you can rely on.
(If at first you don't succeed, do it different next time!)
This was a very interesting documentary. I was particularly interested in the inferences about the user interface approach of Airbus versus Boeing. In short, Airbus planes are controlled with joysticks that translate pilot intentions into actual executable commands to the control surfaces. If the pilot tells the computer to do something stupid, the computer won't do it. Contrast this with Boeing, where the pilots control the plane with a proper control stick that gives more effective feedback to the pilots. In a Boeing airplane, when the computer lowers engine power on autopilot, the engine control lever actually moves in a very visible way. However, on Airbus planes, the levers DO NOT move. The only indication to a pilot that the power has dropped is a small circular readout on a computer screen. The Nova scientists theorized that the pilots didn't realize that the computer had lowered power in anticipation of flying through a thunderstorm, or at least that they realized it too late. They theorize that for about a minute the pilots were flying the plane as if the engines were on high power, when they were actually on a much lower power setting. This, combined with a lack of reliable airspeed data may have caused the pilots to put the plane in an unrecoverable mode of flight. Or maybe it was different. We will know soon enough.
BTW, for those of you outside the US, the above video link won't work. I think the video is on bittorrent somewhere. It is definitely worth watching if you haven't seen it.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
From the telemetry data that I've hear of from the PBS Nova documentary, it seems highly likely that the pitots failed nearly simultaneously, robbing the pilots of airspeed data. Even if they can argue that the pilots could have saved the plane, those pitots should never have failed/froze. There is blame to go around I think.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
I work as an aerospace engineer and we use similar methods during design testing. It's not just cockpit audio that is recorded, there are tens or hundreds of thousands of parameters from systems all over the aircraft. To be honest, the audio may not even be that useful, if it happened fast enough there is a good chance the pilots didn't even know what was going on.
To go through 100,000 variables and prove beyond reasonable doubt that a specific variable directly caused the crash will probably take far more than week. They are likely aiming to just narrow it down to a certain system within that timeframe.
To give context, I recently spent a month trying to narrow down the cause of a failure in a high fidelity engine simulation. And that was a single system that we had the luxury of knowing everything about, and had the ability to rerun the exact situation repeatedly and tune various parameters to determine a cause. Even then the cause is never any single thing, it's often a huge cascading series of minor deviations from the norm leading to an unforeseen combination of events.
the pilots should still be able to bring the aircraft to area where visual flight rule is possible.
The pilots should be able to fly the plane without airspeed data, according to the Nova documentary. They just set the engine to a particular level and maintain a particular angle of attack. The Nova documentary speculated that due to a variety of factors and distractions that the pilots were unaware of the actual power settings of the airplane. Apparently the airspeed/angle of attack window is quite narrow at that altitude, and if the plane deviates from that window, the airplane may become uncontrollable. It may have taken a brief oversight of the power settings to bring down the plane. Sort of pilot error, perhaps. But there were definitely mitigating factors.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
Likely as not, nothing will jump out, especially if, say, the autopilot is flying the aircraft using faulty input, e.g., input from an ice-covered sensor. That is likely to cause other sensors to show perverse readings that may (or may not) be very subtle, and may have multiple or ambiguous causes.
Perhaps, but what will be very interesting is the data on the power settings on the airplane, especially in regard to (a) the autopilot reducing power to 70% in anticipation of passing through a thunderstorm and (b) the pilot's changing of that setting to a more appropriate level. The key question is whether or not the autopilot lowered the power before kicking off due to bad airspeed data, and whether or not (and when!) the pilots realized that the power was lower and what they did in response. That goes to the heart of the speculated cause of this crash, according to the Nova episode on the subject.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
I skimmed through some of the data that was sent through the air, and assuming the time stamps are right, there were inconsistencies that made me suspect some sort of fire in avionics (possibly due to Kapton insulation). Of course, if the time stamps were based on when the data was transmitted rather than when the event occurred, then it's useless, and I withdraw that theory.
I'm certainly interested to see what comes out of all of this, either way.
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Last words: "Oh shit..." (or equivalent in French)
Impetuous! Homeric!
It's probably in French.
Farnsworth: And this is my universal translator. Unfortunately so far it only translates into an incomprehensible dead language.
Cubert: Hello.
Universal Translator: Bonjour!
Farnsworth: Crazy gibberish!
sigfault (core dumped)
BTW, for those of you outside the US, the above video link won't work.
... Canadians may at least want to give that link a try. (And I'd be interested to hear if it does end up working for anyone there.)
I have a friend in Canada who, at least in the recent past with some alternate PBS shows, has been able to view video directly from the PBS site. So
Whoever designed level 61 in Frozen Bubble is a sadistic bastard.
Maybe the co-pilot kept deflating despite the best efforts of the captain to keep him upright.
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If there is a fundamental flaw in the Airbus system, will this invesitgation be allowed to air it to the public? Or will the incestuous goverment ownership / regulation relationship result in a public statement of 'inconclusive' while the flaws (one would pray) are fixed very, very quietly so as not to disturb current and future Airbus sales.
To be fair, I'm not sure such a scenario would be impossible w.r.t. the FAA and Boeing too.
I think you (or the documentary) misunderstood the Airbus design. On their aircraft the throttle is to set the desired thrust, a bit like setting cruse control in your car to a given speed which it then tries to match. Even on a Boeing aircraft the pilot should never use the position of the sticks to indicate thrust levels because if an engine is failing it might not be producing the requested amount. Therefore on both aircraft the readout of actual measured levels is the only reliable indication.
The problem with the Boeing system is that if the pilots exceeds design limits and the aircraft will let them. A number of accidents have occurred because the pilot did something they should not have and the Airbus system is supposed to prevent that. If you look at how many accidents could have been prevented by such a system in the past you can see why they did it. There are of course backups that bypass the limits in the event of the aircraft being damaged or the computer systems failing.
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My gf used to do rescue operations in the military for downed aircraft. In one situation the plane was flying upside down and the pilot rammed the aircraft into the ground thinking he was going up at night as he did not know up from down.
I do not know if the sensors which show orientation were functioning properly or not as they are probably unrelated to the ones that froze up. My opinion is an electrical fault shorted the instruments as data from the flight show this.
This could of created haywire on the computer and instruments in the cockpit. One witness claimed he saw the aircraft fly down sparkling in pieces and fire. Most of the plane is intact on the floor with the exception of the cockpit. The storm was terrible and the plane was getting hit with lightning multiple times and everything from ice to the sensors to perhaps the wings of the plane as well. The thunderheads were over 50,000 feet which is very rare. The whole situation is bad and I wonder why the pilots didn't fly around these storms?
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One witness claimed he saw the aircraft fly down sparkling in pieces and fire.
I am unaware of witnesses to this particular crash. It was in the middle of the Atlantic. If there were direct witnesses, why did it take so long to find the wreckage?
The whole situation is bad and I wonder why the pilots didn't fly around these storms?
The Nova documentary speculated that a smaller storm in their immediate path blocked the radar signals from a larger storm behind it. By the time they realized there was a large ring of storm cells around them, they could not escape. They have radar records of that night, which can be combined with the known flight path. The above hypothesis is reasonable given the data.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
Your Boeings and Airbuses that serve commercial aviation are inherently stable.
I don't believe its as black and white as stable vs unstable anymore. You yourself point out the fact that the margin of error is very small. My understanding is that the A330 is only stable in an extremely narrow flight envelope. It does have fixed pitch/power settings that can be used if the computers fail, but they are extremely suboptimal, so instead the computer fly's it in ranges that would result in a near instant stall if a human were fully at the controls. The operating theory (before the flight recorder recovery) about why AF447 crashed says that the pilots took to long to get it into the correct pitch/power setting (more than a few seconds) after the computer disabled itself. This stalled the plane, and given the weather situation at the time, it probably wasn't possible to recover.
On their aircraft the throttle is to set the desired thrust, a bit like setting cruse control in your car to a given speed which it then tries to match. Even on a Boeing aircraft the pilot should never use the position of the sticks to indicate thrust levels because if an engine is failing it might not be producing the requested amount. Therefore on both aircraft the readout of actual measured levels is the only reliable indication.
Perhaps I wasn't specific enough in my comments. The way I understood it from the documentary, on an Airbus, a pilot's movement of the engine control lever sends a signal to the computer to increase or decrease the power. When the autopilot on an Airbus modifies the power setting, the physical control levers do not give an indication of the change (or the attempted change). On a Boeing, an autopilot change is reflected in a physical movement of the control lever. I agree with you that a pilot should not use the absolute position of the control lever as the most reliable source of engine power output data. However, the Boeing's physical lever movement is a powerful visual cue that the computer has at least attempted to change the engine power, and is a reminder to look at the engine output gauges on the screen. In a stressful situation where multiple indications and warnings are blaring in the cockpit, that physical reminder (or lack thereof) may have been an important factor in this accident.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)