Farnborough Air Show

Final AF447 Report Suggests Pilot Slavishly Followed Flight Director Pitch-Up Commands

 - July 8, 2012, 12:40 PM
The flight data recorder on board Air France Flight 447 was not able to record fligth director behavior. Accident investigators had to "rebuild" data to learn what happened.

In its final report into the loss of an Air France Airbus A330 over the South Atlantic on June 1, 2009, French air accident investigation agency BEA (Bureau d’Enquetes et d’Analyses) has managed to explain most–but not all–of the pitch-up inputs by the pilot who was flying the aircraft at the time of the accident during the last minutes of Air France Flight 447. The report, published on July 5, said that the pilot flying (PF) kept pulling the stick and this caused the Airbus A330 to stall and prevented a recovery.

In a tense press conference held last Thursday at Le Bourget Airport in Paris BEA director Jean-Paul Troadec and his team pointed at human-machine interface issues that made the situation extremely confusing for the crew. All 228 occupants died when the aircraft, flying from Rio to Paris, crashed at night while negotiating a region with heavy thunderstorm activity. BEA had published an interim report in July 2011.

A major new finding in the final report concerned the flight director, which normally displays symbology on the pilots’ primary flying displays that give guidance on control inputs to reach a desired steady-state flightpath. After the autopilot and autothrottle disengaged, as the flight control law switched from normal to alternate, the flight director’s crossbars disappeared. But they then reappeared several times. Every time they were visible, they prompted pitch-up inputs by the PF, investigators determined. It took them a long time to “rebuild” what the flight director displayed since this is not part of the data recorded by the flight data recorder.

The BEA acknowledged that the PF might have followed flight director indications. This was not the right thing to do in a stall but it seems that the crew never realized that the aircraft was in a stall. Moreover, the successive disappearance and reappearance of the crossbars reinforced this false impression, the investigators suggested. For the crew, this could have suggested their information was valid.

None of the pilots recognized that the flight director was changing from one mode to another because they were just too busy. The PF may have trusted the flight director so much that he was verbally agreeing to the other pilot’s pitch-down instructions, while still actually pitching up.

The BEA’s report includes significant recommendations about the flight director. One of them calls for European Aviation Safety Agency to review its “display logic.” The flight director should disappear or present “appropriate orders” in a stall.

The investigators made it clear that from the start the crew should have followed a procedure called “unreliable indicated airspeed,” which involves disconnecting the flight director. They also concluded that the still-connected flight director behaved in a way that is not specific to the A330. However, Leopold Sartorius, head of the investigation’s avionics systems working group, said he did not conduct an exhaustive study on other airliners to determine whether the flight director would have behaved in the same way.

The BEA investigation has explained why the PF pulled his stick after the autopilot disengaged. But he also pulled the stick back at the beginning of the fatal sequence. This was probably to correct what was later determined to be an altimeter error.

The only remaining question concerns the period between autopilot disengagement and the first stall warning. During these five seconds, the PF kept giving nose-up inputs to the controls, but the BEA can’t say why.

The crew (or part of it) trusted the flight director but seemed to ignore the stall alarm even though it sounded more than 70 times. While this fact amazed many industry experts when it was revealed a year ago, the BEA has found possible explanations.

First, the crew was not familiar with this audio alarm, due to a lack of training. More generally, the BEA refers to shortcomings in their “knowledge of the aircraft and its protection modes.” A review of pilot training “did not provide convincing evidence that the associated skills had been correctly developed and maintained.”

Also, the crew may have thought the buffeting, aerodynamic noise and even an acceleration cue on the primary flight display were symptoms of excessive speed. The aircraft, in fact, was in completely the opposite situation in that it was flying far too slowly.

Another reason for having ignored the stall alarm could have been a matter of sheer perception, Troadec said. “Audio alarms are no longer heard in some situations,” he admitted. This has prompted the BEA to recommend the addition of a visual stall warning.

Among the new recommendations are some relatively surprising ones, about problems with the safety oversight of Air France. The BEA refers to failures in inspections conducted by the French civil aviation authority (DGAC), which it said, “did not bring to light the fragile nature of the crew resource management.” Nor did DGAC officials identify the weaknesses of the two copilots in manual airplane handling.

BEA concluded that the DGAC needs to be reorganized to make its safety oversight function more effective. Another recommendation is that there needs to be better recruitment and training of safety inspectors.

Troadec labeled the crew’s work during the fatal few minutes as “destructured.” One difficulty was the lack of a clear display of the airspeed inconsistencies even though the computers identified them. Some systems generated failure messages only about the consequences but never mentioned the origin of the problem. This prompted a recommendation that a blocked pitot tube should be clearly indicated to the crew on the flight displays.

Investigators determined that the A330 pilots being startled by the chain of events played a major role in the destabilization of the flight path and the BEA report recommended more training for dealing with unexpected situations. Ultimately, safety comes from both the pilots’ cognitive abilities and the signals they receive, Troadec concluded.


I'm not surprised that the French were so soft on the final report, as their national airline pilot training was at fault along with the poor interface that Airbus Industries puts into their aircraft. France can never criticise their own faults. My time working with Conair's export division when French training, engineering and maintenance were all at fault in various stupid fatal crashes (including one that killed a friend) were never investigated enough to lay fault where it actually belonged.

Thanks for your comment, Larry. If you read the story, you will see that French investigators are questioning both aircraft system design and crew training.

Conair isn't it a long time ago ?

I saw a similar problem when transitioning from the Lear 45 to the Cessna Sovereign. The 45 was equipped with Honeywell Primus 1000 avionics. This suite verbally announced "gear", "stall", "flaps", etc. The Sovereign with the Honeywell Primus Epic left the crew to decipher a series of bells, clacks, and horns. Pilots shouldn't have to decipher avionics sounds in a high workload environment. The avionics suite should clearly state the offending condition.

Bombardier products have typically had simple and consistent crew alerting philosophies. But then again, I'm biased because I work for them...
Hopefully, 14CFR Part 25 Amendment 25-132 & similar CS-25 Amendment 11 versions of 25.1322 will address such inconsistencies in alerts to the flight crew, cognitive and multi-sensual aspects, as well as the need for distinct alerts for situations which require "immediate" crew action, for all future products, irregardless of make or model.

Did any of the two FO's have a multi crew license that the Europeans had been pushing for in the past? If so this accident will further harden the FAA and Congress's stand against it.

Sully said it all:

"This accident will be a subject of discussion for years to come."


The pompous French pilots' union even refused to co-operate with the BEA's AF447 investigation. The pilot who flew it into the Atlantic held the sidestick fully back the whole time whilst the altimeter spun down uninterrupted at 10,000 feet per minute. Any sane person would avoid French aviation. Even a kid with airplane video-game experience could do better.

Why didn't the crew use the GPS speed? I have used it for over 15 years and NEVER had a problem. How sad that they did not use a simple $50 tool to tell them that the plane was moving too slow.

GPS only reports ground speed: if you're climbing or descending (especially at high rates like 10,000 ft/min), GPS readings will not give you accurate data of your true airspeed, especially in a stall situation where your attitude & AoA has a high rate of change. It might however allow you to validate the primary airspeed indications (cross-check) and identify any possible discrepencies...

But more importantly, an airplane design (especially a FBW one) must be robust to failures of primary air data sources (especially from common causes, such as icing), especially with an increasing number of valid alternate sources (such as IRS and GPS, and good old trusty AoA vanes) that could be used.

It is simple. you get what you pay for. When you put two under-qualified
pilots in a complex aircraft and let them wander into dangerous conditions people
end up dead. Airbus has decided that the aircraft they build are smarter than the pilots; so Air France has decided: why invest in competent pilots?

A very smart man told me once: you cannot buy experience, but you will
certainly pay for it.

Is it just me, or does anyone else feel that the 224 page final report doesn't adequately analyise the A330's handling qualities or controllability in alternate law in cases of failures of primary air data sources (such as the probes icing up) as a possible contributing factor? Although the PF's unexplained nose up inputs are obviously ones the main contributing factors, can we really explain all the lateral and directional deviations (and associated compensating PF control inputs) recorded by the FDR?

The primary cause of the AF447 crash was the lack of leadership of the aircraft captain. He was unable to exercise a basic understanding over the situation in taking charge of the problem and in controlling the other 2 pilots actions. Effectively nobody was really in charge on board: all pilots were doing their silly things without central coordination of actions and without specific directions of the aircraft captain.

The pilots were overreacting to flight displays and bells warnings generated by the aircraft avionics in total disorganisation ans despair without any coordination of efforts and applied knowledge of the very basic flight mechanic principle. They had forgotten how to fly an airplane!

A reading the report strongly suggests that pilots were not trained at working as a team but rather as individuals with their own view of the situation and character.

The lost of this AF447 planes and its 227 passengers is a consequence of inexistent leadership on board and without this basic ingredient all recommandations of the report will be ineffective in the future.

The official report was a whitewash of total pilot incompentence.

If the returning captain had said, "C'mon lads, let's have a Gauloise and a coffee in the galley", thereby allowing the plane to level-off by itself at altitude, they would have lived to tell the tale!

The accident was caused by the co-pilot induced stalled glide condition and remained in that condition until impact. To recover from stall is to set engine to idle to reduce nose up side effect and try full nose down input. If no success roll the aircraft to above 60° bank angle and rudder input to lower the nose in a steep engaged turn. Pilots lack of familiarity and training along with system malfunction contributed to this terrible accident. Also the following contributed to the accident
(1)the absence of proper immediate actions to correct the stalled glide
(2) Insufficient and inappropriate situation awareness disabling the co-pilots and the captain to become aware of what was happening regarding the performance and behaviour of the aircraft
(3)lack of effective communication between the co-pilots and the captain which limited the decision making processes, the ability to choose appropriate alternatives and establish priorities in the actions to counter the stalled glide
During most of its long descent into the Atlantic Ocean, Airbus A330-203 was in a stalled glide. Far from a deep stall, this seems to have been a conventional stall in which the Airbus A330-203 displayed exemplary behavior. The aircraft responded to roll inputs, maintained the commanded pitch attitude, and neither departed nor spun. The only thing the Airbus A330-203 failed to do well was to make clear to its cockpit crew what was going on.Its pitch attitude was about 15 degrees nose up and its flight path was around 25 degrees downward, giving an angle of attack of 35 degrees or more. Its vertical speed was about 100 knots, and its true airspeed was about 250 knots. It remained in this unusual attitude not because it could not recover, but because the co-pilots did not comprehend in darkness, the actual attitude of the aircraft. The co-pilots held the nose up. If the co-pilots had pushed the stick forward, held it there, and manually retrimmed the stabilizer, the airplane would have recovered from the stall and flown normally.

Air France complained that the copilots did not have enough time to analyze the situation. Gravitational stalled glide does not allow timeouts, to thoroughly discuss the situation to find out what went wrong. The co-pilots - 37 year old David Robert and 32 year old Pierre-Cédric Bonin missed the cardinal rule that first they must fly the airplane, and after start analyzing the situation, since a falling airplane is not going to wait for them. If they did not understand the instruments, then instead of pondering on it they should have come to the quick conclusion that they did not understand those instruments, and apply the unreliable airspeed procedure clearly prescribed for that situation, which is a blind, given thrust and pitch setting for the given configuration, and let the airplane fly itself, and only after get to analyzing what went wrong, and by the time they finished, the root-cause (pitot icing) would have probably cured itself. It was the safe solution to the problem, but not applied.
The Airbus A330 performed exactly as it was designed and described when the stall warning cut out at the end of valid values, except the co-pilots did not know it. Unfortunately, it happens too often with catastrophic results that pilots are not familiar with the systems of their own airplane, such as in the case of American Airlines 587 over Queens, which was clearly the airline’s fault.
Air France also argued that the stall warning system in the A330 is too “confusing”. Every modern airplane is quite a confusing piece of machinery. It is full of buttons, levers, all kinds of red, yellow, green lights with buzzers, and a host of other indicators and controls inside, which can look very confusing indeed, but it is the pilot’s duty to reign on them, or not to be pilot.
Airbus A330-203 is a new generation, highly automated piece of equipment with drastically simplified controls, displays, and instrumentation compared to older models. Still, pilots with the same human capabilities as the ones on Air France flight 447 could very well stay in full control in those planes, and many times acted heroically saving situations much graver than where the plight of Air France flight 447 started, such as United Airlines flight UA232 at Sioux City, or Air Canada flight AC143, the Gimli Glider. If those pilots could perform well in those older, much more complicated aircraft in tougher situations, then there is no excuse for the co-pilots of AF flight 447 to be confused in a generally much simpler and easier-to-fly aircraft.
The Airbus A320 is a digital fly-by-wire aircraft as the flight control surfaces are moved by electrical and hydraulic actuators controlled by a digital computer. The computer interprets pilot commands via input from a side-stick, making adjustments on its own to keep the plane stable and on course, which is particularly useful after engine failure by allowing the pilots to concentrate on engine restart and landing planning. Some say the Airbus A330 is a “video-game” airplane due to its side-stick control, which does not match up in real hard situations. But who can say that after the successful ditching of US Airways flight 1549 on the Hudson River? It was an Airbus A320 with the same side-stick control, and it matched up with the hardest situation very well with an experienced 57 year old Captain Chesley Sullenberger at the command. The Airbus A330 is not a video-game airplane, it is the airlines that make it a video-game by cutting corners, taking advantage of its superior automated capabilities thinking that it flies by itself, and no training and no knowledge of even the basics of the principles of flying is required in them for their pilots, as was demonstrated by the co-pilots of flight 447, who seemed to be incapable to react even on a basic level to the phenomenon of the aerodynamic stall. The co-pilots had not applied the unreliable airspeed procedure. The co-pilots apparently did not notice that the plane had reached its maximum permissible altitude. The co-pilots did not read out the available data like vertical velocity, altitude, etc. The stall warning sounded continuously for 54 seconds. The absence of any training, at high altitude, in manual airplane handling and in the procedure for ”Vol avec IAS douteuse” (Flight with questionable Indicated Airspeed) caused this terrible accident. Evidently, it might not be what Airbus had on its mind designing the aircraft. They might have meant the best of the both, an airplane with superior controls, matched with seasoned pilots with superior education in the principles of flying and the handling of hard situations, best of the best, as airlines are prone to boast of their flying personnel, to represent quality improvement in flying safety by this pairing. Now, if this piece of equipment falls in the hands of the airlines who use it as a video game to save training costs, telling only their pilots that “if the red light on the right side blinks, just pull the stick back as hard as you can, and let the system do the rest”, they can get away with it as long as everything is normal, the airplane is good enough for that, but in unforeseeable situations, such as the flight 447 en-route to Paris on that night, without any independent knowledge of flying in general, the video-gaming with the aircraft may ultimately come to a fatal end.
However, beyond the reasoning and explanations there is still some eeriness about the crash, taking in consideration that Air France flight 447's pilots just sat there in daze squeezing the control stick, barely being able to do more than commenting on how the airplane was falling out of the sky until crashing into the Atlantic Ocean, the arrival of the 58-year-old flight captain Marc Dubois in the cockpit not making much a difference either. The question might arise whether weren’t the pilots in a mentally incapacitating state of shock and disbelief? Whether do or can Air France test pilots of how well they can keep their mental stability under the duress of a catastrophic situation? None of it seems to be the fault of the Airbus A330, which needs only good, trained pilots to give superior performance for the good of the flying public. Very similarly 3 decades ago Captain Madan Kukar's mistaken perception of the Air India Flight 855 situation resulted in causing the Boeing 747-237 to rapidly lose altitude and the airplane hit the Arabian Sea at 35 degree nose-down angle.
Practicing recovery from “Loss of Control” situations and improve flight crew training for high altitude stalls (simulator training usually has low altitude stalls which are significantly different due to energy status of the aircraft) should become the mandatory part of recurrent training.

Very well said... Thank you...

Your description and conclusions are superb. I agree with You 100%. By the way. The automation and operations of an Airliner like A330 has gone too far. Pilots do not properly learn how to fly these planes. They are too complicated in their automation and smartness. The flying should not be so complicated as it is today. As a former B767 pilot i allready at that time 12 years ago felt like the automation had gone too far. The most common pilots question when flyin should not be."What the hell is happening. Why is it behaving like this. How shall we get out of this?

A question to the bus pilots. With the side stick, is the stick shaker stall warning gone and it is only an Audible alarm now.

I propose the following vocal schemes.

(1) "AUTO throttle 100 percent"
This happens when the the plane flies too slow. It automatically increases the thrust to attain a minimum speed. This is done by the autopilot.
(2) "WARNING overspeed.", "Warning too slow.", "Warning stall.", "Warning too high."
Indicates a status it shouldn't be in. Prior to maybe the auto pilot taking over control like above.
(3) "PILOT gear down.", "Pilot flaps 10."
When the pilot puts his gear down, the on board computer verbally tells the pilot that the gear is down. This gives information to not only the pilot but also the copilot.

These 3 types of verbal or auditory information must be done with 3 different voices. One of which must be Captain Picard. :-)

Maybe there is a possibility to add one more.
(4) "STATUS fuel 20 percent."

There should be a master switch to turn the autopilot off. But litterally everything off. Even when the plane flies too slow. The auto throttle shouldn't turn on. It should stall. It's everything on the pilot.

A on board flight simulator wouldn't hurt. Pilots could use it for training or in their spare time and passengers can use it for a fee.

Two comments. First, had any of my student pilots (who recover from stalls numerous times in their pre-solo training alone) been on that flight deck, they would have been screaming "Release back pressure!" Second, Airbus wanted their advanced flight deck to be as different and futuristic as possible (in their mind, "so much more advanced") than Boeing's. SO, they incorporated side stick controllers that the PNFs could not directly see what pitch angle was being commanded. Had this been a Boeing cockpit, I have to believe that at some some point in this event, one of the PNFs would have seen the yoke pulled back in the PF's lap, had an epiphany, and said "Release back pressure! We're in a stall!"

Flight Director: Tells what to do: Pitch up or Down, sometimes in spite of aircraft configuration, attitude, or actual flight path.

Flight Path Marker: Tells what the aircraft is doing, either assending or descending, whether nose up or nose down. Example: In nose up attitude but descending, the Flight Path Marker will display the aircraft's actual flight path below the horizon.

I'd suggest in this situation, many pilots might have bought the farm on a pitch black night with confusing Flight Director cues. Lets think about the average guy suddenly faced with confusing nightmarish information, none of which seemed to make any sense. More training and CRM? Of course! But lets look at the equipment, too.

Do you think the PF, out of fear, was pulling back in hopes of topping what must have been a horrific weather event?

Yes but he omitted to realise he didn't have Concorde's engines on full after-burner to pull it up.

understanding the comment in the report that suggests that successful recovery was not possible even as early as when the Captain returned to the cockpit, yet the a/c was still above FL300.

Warfare will continue until 2 big manufacturers possibly with others sit down and re write the rules of aviation again... This accident although it still looks very strange to me, was caused by a pilot error. Two relatively young pilots with chain of misfortunate happenings, were left with their blinded abilities due to complex automation... The complex automation now exists in everywhere and everything including in our household equipment, a pressure drop voltage failure whatever you name it appears on a display to puzzle whom looks at that without having a clue.. I dont accept the fact that Air france did not train its pilots for stall training whether it is low or high altitude.. Secondly, Airbus with all its safety reputation made its airplane somehow interestingly illogical at certain point where 2 sidesticks movement are all the time averaged and resultant direction steers the aircraft..
Another issue is the relying only and solely on pitot tubes which have been proved to be susceptible to any type of atmospheric phenomena..

Concluding this, To save airliners future for keeping the low budget flights, this is actually what you pay for .. sometimes our lives... The re current training of safety of aircrafts to all pilots, introducing extra safety measures to existing aircrafts are extremely costly.. Grounding a fleet for those modifications can result in bankcruptcy..

Somehow we are all victim of the developments and AF 447 will be another example of making the avitation safer in other words making Man machine interface much simpler in this case.

Learning how to fly an airplane safely is very important, and also very costly. One resource I've found is skypark.tv, which is trying to return some focus of the aviation world to small airports and private aviators.

I am sorry to interrupt your conversations but I am intrigued by what you say for my 39 year old uncle was on that flight and I felt as it was my fault for I had never been nice as I should have to him... I was about seven an dit corrupted my learning and I still feel quite horrible... Anyway we know the cause of that accident was the black boxes and for a ten year old child such as me that is enough... My father was vice-president of an association that had lost their beloved ones and he made the search continue their search... sorry of topic anyway, it is the black boxes that were giving false information to the pilot so it is a faulty airplane and not a crew members fault.

I am sorry to interrupt your conversations but I am intrigued by what you say for my 39 year old uncle was on that flight and I felt as it was my fault for I had never been nice as I should have to him... I was about seven an dit corrupted my learning and I still feel quite horrible... Anyway we know the cause of that accident was the black boxes and for a ten year old child such as me that is enough... My father was vice-president of an association that had lost their beloved ones and he made the search continue their search... sorry of topic anyway, it is the black boxes that were giving false information to the pilot so it is a faulty airplane and not a crew members fault.

I'm sorry for your loss, Clarisse Clemes, but despite what you say it yes most certainly was partly the fault of the crew, this terrible airline disaster.

During descent to the sea, what did the FMAs (Flight Mode Annunciators) indicate? If his F/D was still in the altitude hold mode, it would have commanded a "nose up" attitude to return to its captured altitude/flight level. If, on the other hand, the pilot flying had pushed the throttles up to TO/GA, the F/D would have commanded a safe flying speed above stall and not a command to return the previously captured flight level.

Among other errors, this crew failed to look at/understand what mode(s) the flight director was commanding.

Anyone know if Air France has made any changes to aircrew training or flight deck procedures as a result of the loss of AF447.

Has Airbus made any changes?

Was there an alternate airspeed feed if the pitot tube froze?

Anyone know if Air France has made any changes to aircrew training or flight deck procedures as a result of the loss of AF447.

Has Airbus made any changes?

Was there an alternate airspeed feed if the pitot tube froze?

Being an Airbus pilot I can assure you that Air France and Airbus are covering up what really happened because Airbus does not want to fix thousands of defective rudders that come off in turbulence.  If you are interested check out the number of world wide crashes involving Airbus A-300 and you will see that I am correct.

Four (4) A-300 series Airbus aircraft have crashed and all of them encountered strong turbulence then lost their rudders because the rudder attachment is too weak and would require about 500 additional pounds of reinforcing metal and materials to beef it up properly at a cost of about $72 billion dollars.   

This is precisely what happened to AF-447 because the rudder was found floating 50 miles south of the main wreckage with no leading edge damage.  The rudder photos clearly show the AF-447 rudder came off in flight because the leading edge is undamaged.

In order to simulate the Air France crash condition one needs to use a flight simulator.  Once the rudder comes off the aircraft pitches up dramatically due to cabin pressure escaping out which in-turn pushes the tail down and the nose up.  This is exactly what happened to AF447.  The first automatic alarm transmission was that the cabin lost pressure (which occurs when the rudder is ripped off) followed by an low airspeed alert which is caused as the aircraft is pointed up it loses airspeed, followed by the auto-pilot being disconnected, followed by a stall not because the pitot static probes iced ups because the probes are always heated in excess of 250 degrees and will not ice-up as claimed.  In any case, there are three probes and all three will not ice-up at the same time and it cannot be duplicated and is Bull Shit.  Iced up pitot static probes will not and cannot happen as Airbus wants us to believe.  As the airspeed slows down with the nose pointed up the pitot static probe temperatures will actually increase because high airflow removes heat and low airspeed allows the probes to heat to temperatures above 350 degrees and ice will not form and there is not science in that theory. 

I hope there is a forensic journalist who would like to take this case on because it will save lives if the Airbus rudders are ultimately repaired and we can show the world that cover ups hurt everyone.    

In the Airbus simulator one cannot duplicate what Airbus wants you to believe that 3 well trained pilots would try to stall the aircraft then hold it in the stall for 4 minutes and 19 seconds.  The fact is that no pilot would do that and it cannot be shown in a simulator because it did not happen.   The only way the aircraft will climb after entering turbulence is if it rudder which opens a hole allowing cabin air to shoot up.

I hope that the AF 447 investigation is reopened and that Airbus is compelled to repair the rudders before this happens again.  Remember the B-737s of which three different aircraft rudders reversed with two crashing and one recovered in flight which showed why the first two crashed.   Four (4) Airbus A 300 series have crashed and all of them first lost their rudders in turbulence… then they all crashed and everyone was killed.

I hope the fleet is repaired before we have another Airbus A-330 crash killing innocent people.  No pilot will purposefully stall and aircraft then hold it in the stall for 4 minutes 19 seconds. 

Captain James Venetti  

Dear Capt Venetti,

Your coment is truly troubling if you are in fact a pilot as you claim. If you take the time to read the accident report and the cockpit voice recorder transcripts you will understand what the pilot(s) must have thought they were doing when the incident occured. Airbus A330s are fly-by-wire aircraft, side-stick controlled, with built in envelope protection. Under normal circumstances, they cannot be stalled as the flight control algorithms prevent the pilot from inducing excessive angles of attack, in the case of AF447 the iced-up pitot tubes caused wild fluctuations in airspeed reading. The flight controls then defaulted to 'alternate law' due to the airspeed disagree condition, but the pilots continued to fly the aircraft as if normal envelope protection was still active (where it is still possible to fly with the stick full back without stalling) - perhaps one or both of the pilots believed this was necessary to bleed off what they thought was excessive airspeed? - We will never know, but the ensuing confusion and intermittent stall warnings failed to alert the crew to the severity of their situation and the resulting stall caused the crash. The ultimate 'cause' of the accident was the combination of weather-induced pitot tube failure leading to inappropriate crew response to what was essentially an airspeed indication failure, this being evidently due to deficient training in Airbus flight control laws at Air France. All they had to do was fly straight and level.

The rudder problems on A300 were and still are serious, but that is not even relevant to AF447, it is truly troubling that someone who claims to be in command of an aircraft could so wrongly and flagrantly attribute cause and blame in such a manner. I sincerely hope, for the safety of your passengers, that you are not in command of an Airbus, as it's clear you simply don't understand how they work.

In fact, I will go one further and openly appeal to any Airbus pilots reading this, that if you do not know and understand the severity of what 'ALTERNATE LAW' means, please educate yourselves. Your airline is failing you if you are not trained how to appropriately control an Airbus when envelope protection is switched off, or what to do when your instruments fail.


Anonamous concerned systems engineer.

Wouldn't it be cool to have a set of instrumentation gauges that provide basic altitude, longitude, speed, and some other basic readings BUT relying on their own power source,  independently from the main aircraft? This way, if the aircraft's instrumentation fails, pilots would have a back-up to orient themselves specially at night or in thick clouds.  



Yclax and others: This Airbus, as all transport aircraft. WAS equipped with a small, independently powered "attitude indicator" which displays the aircraft's orientation to the earth's horizon. For those unfamiliar, it is the globe like instrument easily seen when boarding your flight which is brown on the lower half and blue on top depicting the ground and sky.

Any aircraft can be kept in level flight by using the stick or control column to keep this indicator on or slightly above the horizon line, and manually adjusting the power levers to give sufficient engine thrust. No other information, including airspeed indication, is required for one pilot to keep the keep the plane safely flying while the rest of the crew works on restoring the slightly less critical features such as navigation and altitude data.

What is very surprising, and somewhat disturbing, is the use of the standby attitude indicator was not once mentioned by participants in this old thread over the years it has been up on AIN.

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