AF447: Flight Data Recorder Recovered

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Originally Posted By: MolaKule

Neither are completely flawless, but don't you think the pilot, with more flying experience than the computer (which has only control law sofware), should make the final decision? I do and that's why I favor the Boeing FCS.

Until the computer can be programmed with highly redundant Artificial Intelligence, I favor full pilot command, real-time human intelligence.


On the other hand, one needs only to ask this question: how many accidents are the result of human errors?

There is no simple answer to the question of which design philosophy makes more sense. The fact is, both Airbus and Boeing make extremely safe and reliable airliners.
 
Originally Posted By: dkryan
Considering a criminal investigation is underway involving this mishap, Airbus will not have the final word as to the cause and the in-depth analysis will likely occur.


The criminal investigation is not particularly significant. In France, it is a standard procedure to open a criminal investigation whenever there are fatalities in an accident. It does not in any way imply a criminal act has been committed.
 
dkryan -

Did an interim report really come out? Not sure how much of your statement you indicated was a joke...I haven't seen anything in the press about an interim report. I have been having many discussions with my colleagues about this - can you provide a link to any early reports that have come out?
 
No interim report has been issued since the CVR and FDR were recovered and read. Airbus did issue a notice that based on the first look at the data that no new advisories or actions were forthcoming from Airbus in the short term. Simply means that there was no information at this time that suggested that any actions need to be taken by operators of the type above and beyond what has already been done.

Does this mean the accident was caused by pilot action (or inaction)? By the theory on the bad speed data? We don't know yet, and the official information from Airbus doesn't contradict any of those theories that exist. It only means that nothing they've siad before has changed.
 
What if the Pilot, in his final decision, forgets to change another setting that is required for the move he is attempting to make, and that results in a crash? In the Boeing, that is possible. In the Airbus, the required setting would be changed by the computer or move would not be allowed, depending on what the situation is.

There are fierce allegiances to both design philosophies. I'm in the camp that both manufacturers make fine, though different, airplanes. The proof is in the excellent safety statistics of both manufacturers.
 
Originally Posted By: hhu168

At 33,000 feet, the pilots, just like the computers, rely on the pitot sensors for speed information. If the readings were wrong, in all likelihood the pilots would want to "correct" the plane speed just like the computers would.



Really? I would never pull power to idle when I desire cruise power. Even a lowly pilot like me knows the fuel flow numbers, the general percent of RPM, typical AOA, and other factors to look at.
 
Our flight department operates a Gulfstream G550. It employs conventional flight controls, but does use FADEC (computerized engines), along with a fully automated cockpit (Honeywell Primus EPIC).

Guess what happens that the engineers never, ever considered? The engines roll to idle, the throttles lock up and are non responsive when the TAT probes (total air temp) fill with microscopic ice crystals while in cruise flight. This happens when over or next to large thunderstorms (not in), as they spit invisible ice out the top.

Over the pacific, we lost over 30,000 feet of altitude this way. The solution? A reboot! Sorry, but I want control, full control.

The reason? The temps are outside the "possible limits" (above freezing above 49,000 feet) and therefore the engines computers "lock up", often at far lower thrust levels.
 
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Originally Posted By: btanchors
dkryan -

Did an interim report really come out? Not sure how much of your statement you indicated was a joke...I haven't seen anything in the press about an interim report. I have been having many discussions with my colleagues about this - can you provide a link to any early reports that have come out?


Clarification: it was not an interim report, but rather a bulletin from Airbus, as MNgopher cited above.

At the risk of drawing the ire of News Corp., and more specifically, the Wall Street Journal online, here is an excerpt from their article. I'm not posting the article in its' entirety for obvious reasons. Read what is available below and interpret it anyway you want:

"Airbus Suggests Its Jet Didn't Fail in Crash"

By ANDY PASZTOR And DANIEL MICHAELS - The Wall Street Journal, May 18, 2011

"European plane maker Airbus, providing the strongest sign yet that pilot error may have led to the 2009 crash of an Air France jetliner, said data recorders recently recovered from the wreckage don't indicate any massive aircraft malfunctions before the fatal dive.

In a bulletin sent to airlines Monday, Airbus said a preliminary readout of information about the Airbus A330 that crashed into the Atlantic Ocean two years ago hasn't prompted any "immediate recommendation" regarding the safety of the global A330 fleet. (Ed.-that quotation mark is from the writers, not me)

The statement suggests that industry and government experts—led by France's air-crash investigation bureau— are focusing more on human error and cockpit procedures than major problems with specific airplane components or onboard computer systems

But the Airbus move, at such an early point in the data analysis, is particularly revealing because the message was approved by French government investigators leading the high-profile probe into the accident, which killed all 228 aboard. Investigators presumably wouldn't have given the green light if they were delving into a significant, newly uncovered aircraft malfunction that could affect all widebody Airbus A330 or similar A340 jetliner models.

Based on early analysis of the plane's flight-data and cockpit-voice recorders, or black boxes, the Airbus message said there aren't any urgent safety issues "to raise to operators" of hundreds of A330s world-wide. Additional updates will come "as new significant information becomes available," Airbus privately told carriers.

The latest developments are a replay of some of the tensions that emerged between Airbus and Air France, one of its largest customers, in the aftermath of the crash. Each company previously tried to influence public perceptions and shift blame to the other, and now safety experts on both sides of the Atlantic say some of the same tactics appear to be resurfacing.

On Tuesday, Airbus issued a written statement saying it "strongly disagrees with any form of speculation" by the media about the scope or focus of the investigation.

Seemingly trying to step back from the finger-pointing, the Airbus statement also said the company "deplores all inappropriate communication concerning such a serious event that should be handled with professionalism and dignity."

End of excerpts.

Nice, huh, how Airbus makes the statement directly above, just after releasing a bulletin that says: t'ain't our fault here at Airbus!

The rest of the article focused on aerodynamic stall.
 
Originally Posted By: Cujet
Originally Posted By: hhu168

At 33,000 feet, the pilots, just like the computers, rely on the pitot sensors for speed information. If the readings were wrong, in all likelihood the pilots would want to "correct" the plane speed just like the computers would.



Really? I would never pull power to idle when I desire cruise power. Even a lowly pilot like me knows the fuel flow numbers, the general percent of RPM, typical AOA, and other factors to look at.


Are you saying the six computers would pull power to idle without looking at the "other factors"? You really believe that?
 
Originally Posted By: Cujet
Our flight department operates a Gulfstream G550. It employs conventional flight controls, but does use FADEC (computerized engines), along with a fully automated cockpit (Honeywell Primus EPIC).

Guess what happens that the engineers never, ever considered? The engines roll to idle, the throttles lock up and are non responsive when the TAT probes (total air temp) fill with microscopic ice crystals while in cruise flight.


What you have experienced is an engine control problem and not an EPIC FMS problem. You could have decoupled the FMS and fly manually at any time, which should be no problem since you were in CRZ. The FMS does not control the engine, it controls the throttle while in AP. Our team at Honeywell FMS are the one developing the EPIC and the current NG FMS systems. We would have been done with G650 CERT1 if it was not for the crashed prototype in April.
 
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Well, you can call it an interim report, preliminary report, bulletin, or notice, but here it is.............

Black Boxes Point to Pilot Error

By ANDY PASZTOR And DANIEL MICHAELS

The Wall Street Journal online edition - May 23, 2011

Partial excerpts -

"The pilots of an Air France jet that crashed into the Atlantic Ocean two years ago apparently became distracted with faulty airspeed indicators and failed to properly deal with other vital systems, including adjusting engine thrust, according to people familiar with preliminary findings from the plane's recorders.

The final moments inside the cockpit of the twin-engine Airbus A330, these people said, indicate the pilots seemingly were confused by alarms they received from various automated flight-control systems as the plane passed through some turbulence typical on the route from Rio de Janeiro to Paris. They also faced unexpectedly heavy icing at 35,000 feet. Such icing is renowned for making airspeed-indicators and other external sensors unreliable.

Ultimately, despite the fact that primary cockpit displays functioned normally, the crew failed to follow standard procedures to maintain or increase thrust and keep the aircraft's nose level, while trouble-shooting and waiting for the airspeed sensors and related functions to return to normal, according to these people.

Slated to be disclosed by investigators on Friday, the sequence of events captured on the recorders is expected to highlight that the jet slowed dangerously shortly after the autopilot disconnected. The pilots almost immediately faced the beginning of what became a series of automation failures or disconnects related to problems with the plane's airspeed sensors, these people said.

The crew methodically tried to respond to the warnings, according to people familiar with the probe, but apparently had difficulty sorting out the warning messages, chimes and other cues while also keeping close track of essential displays showing engine power and aircraft trajectory.

The Air France pilots were never trained to handle precisely such an emergency, according to safety experts and a previous report by France's Bureau d'Enquetes et d'Analyses, which is heading up the investigation. All 228 people aboard Flight 447 died in the accident.

The senior captain, Marc Dubois, appears to have been on a routine rest break in the cabin when the fatal chain of events started, according to safety experts familiar with the details, but the cockpit-voice recorder suggests he may have rushed back to the cockpit to join the other two Flight 447 pilots."

The rest of the article talks about the airspeed pitot tube, etc.

Three pilots in the cockpit trying to sort out all of the warnings. Somehow, I'd like to think it was not a return to the flight that crashed in the Florida everglades decades ago because the flightcrew became so focused on the "situation," that someone forgot to fly the airplane.

However, between suspect airspeed pitot tubes and "over-automation," one has to wonder when you've reached "too much technology."
 
There had to be some serious automation failure. You can not stall a Bus unless flight controls were degraded to ALT, Abnormal or Direct Law from a serious electrical problem. Iced pitot tubes would only cause the autopilot to disconnect not cause a change in Law. Hmm something had to have went wrong on the aircraft itself. As for the pitots, static, angle of attack probes and total air temperature probes are all automatically heated in flight. Icing shouldn't have been a problem, but I'm unfamiliar the problems with Airbus pitot tubes as I haven't flown the 320 in a while. But if they're were flying in severe icing or a hidden thunderstorm I could see it getting iced up.
 
For now, I'd call that a news story based on unnamed sources. The amount of speculation about what actually happened, along with "leap to conclusions" types of news stories has been unreal. I suppose it is the not know exacatly what happened on a modern airliner that has everyone jumping at new information.

Until an official report comes from the BEA, its safe to say the news stories may or may not be fully factual. Tough to say.
 
What I also don't understand is when AP is disengaged the throttle is not automatic reduced so they should still have enough speed to maintain Vmin. All pilots should know the approximate throttle setting to maintain crz speed, so unless the pilots reduced the throttle then there is something else wrong with the aircraft. BAE will rerun the crash data on their simulation and should be able to determine the source of the error.
 
Pee-tow.
crackmeup2.gif
You guessed it, it was invented by a Frenchie.
 
Originally Posted By: azsynthetic
What I also don't understand is when AP is disengaged the throttle is not automatic reduced so they should still have enough speed to maintain Vmin. All pilots should know the approximate throttle setting to maintain crz speed, so unless the pilots reduced the throttle then there is something else wrong with the aircraft. BAE will rerun the crash data on their simulation and should be able to determine the source of the error.



If they were in icing conditions bad enough to ice the whole plane to make it fall out of the sky theres no power setting to recover. Think of it as taking a 53' foot semi trailer and putting one on the leading edge of each wing, thats how much of an effect on the air flow over the wings that much icing would cause.
 
All kinds of bad things happen when the pitot system ices over. This is nothing new in aviation. In fact, this happened at Northwest Airlines in 1974 in Stone Point, NY. Here's the report: http://aviation-safety.net/database/record.php?id=19741201-1 Here's the NTSB Report specifically citing airframe icing as a contributing factor in this accident: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR75-13.pdf

The Air Florida crash into the Potomac River in Washington, DC was caused by iced over engine instruments showing greater thrust than it actually was. Here's a summary: http://en.wikipedia.org/wiki/Air_Florida_Flight_90

Since that point in time, newer designed aircraft had the pitot system and engine probes heated from the time of engine start.

Several points of information: The Airbus family of aircraft has autothrottles, but those throttles do not move from a climb detent position. In fact, if you disconnect the autothrottles, without matching up the throttle position, you will get either an increase in thrust or a decrease. Under normal operations, the throttles are moved only three times. 1) When takeoff power is applied. 2) when climb thrust is set at 1000' AGL. 3) In the landing flare, when the RADALT computer calls out "retard" to bring the throttles to idle.

When the pitot system is iced over, the airspeed indicator turns into an "altimeter" which will show higher and higher airspeed as you gain altitude. A pilot sees that climbing airspeed and pitches up to reduce airspeed, but at high altitudes, you can bring the aircraft into a deep stall. A deep stall at altitude can create a flat spin, for which there is no way out in a transport category aircraft. (That's what happened to the Northwest Crash in Stone Point, NY.)

In this specific accident, there is some information that the airplane encountered a very warm, humid core of rising air. The airplane had been cruising at 35,000 feet, with normal outside air temperatures of -54 degs. C. You can imagine what would happen if something so cold-soaked flew into warm, moist air. Instant ice all over the aircraft. FYI: the aircraft tail sections on most commercial aircraft do not have anti-icing capability. My point being, you are now a test pilot if you have instantly iced over at 35,000 feet.

Finally, there were a multitude of cauthions and warnings on this flight. When that happens, the lower ECAM shows each condition and subsequent sub system failures along with a corrective action. If there were warning upon warning, it would be easy to become overwhelmed.

The first action item in any emergency is to FLY THE AIRPLANE. One pilot must fly. Let the other pilot handle the emergency. That's why there are 2 pilots instead of one.

Finally, we wouldn't be talking about any of this had the crew elected to deviate around the thunderstorm activity. Why they chose to penetrate a line of weather baffles me to this day. I always deviate: there is never a delay when it comes to safety.

Sorry for the long post...

757 Guy
 
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Thanks for the info 757 Guy. I wasn't aware of the weather at the time of the accident. With that information it's not so much of the wings getting iced but the WHOLE aircraft. Wikipedia has been updated saying autopilot and auto throttles were disconnected and flight controls went to alternate law. Also penetrating a line of weather was a huge mistake also.
 
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This whole started with the Air Data Computers giving bad information to the Flight Control Computers. If there were a sudden rise in temperture, that airplane would have been way over gross for that altitude. (You need that cold -54 deg. air for cruise flight at that altitude and weight.)

Now everything ices over, and the altitude information is wrong, the airspeed information is wrong, the angle of attack may be wrong, so the airplane says: I give up.

Inside a thunderstorm is a bad place to be when the automation gives up, you are too warm to maintain that altitude, and you are dealing with multiple cautions and warnings. ADIRU's may have given up too, so no artificial horizon.

It's night outside, over a dark ocean, moderate to severe turbulence and you have no idea as to which way is up.

That would be a nightmare scenario for anyone.


757 Guy
 
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