Air France Flight 447

[OregonMaule]

Maybe some of you have been following this, I know I have.

Hard to believe with all the electronics, sensors, do dads, gizmos and whatchamacallits that three pilots could crash the Air Bus because they had no air speed sensor. WTF???

http://www.avweb.com/eletter/archives/a ... tml#204730

Excerpts from flight data recorder.
"For nearly the entire 3½ minutes before they crashed into the ocean, the pilots did the opposite, holding the Airbus A330's joystick back to lift the nose."

If you want to go up, pull back, If you want to go down pull back all the way. They were going down at 122MPH over 10000 FPM with engines producing full thrust.

Air France 447 — How Did This Happen?

The pilots of Air France Flight 447 flew the aircraft into deep stall at 38,000 feet, never verbally acknowledged or corrected that condition, and the aircraft fell for more than three minutes at nearly 11,000 feet per minute into the Atlantic, killing all aboard, investigators said Friday. The jet maintained a nose up attitude -- along with an angle of attack greater than 35 degrees -- throughout a descent rate that translates to more than 122 miles per hour of vertical drop. "At no point" on the cockpit voice recorder "is the word stall ever mentioned," Chief Investigator Alain Bouillard said in an interview. The autopilot and auto-throttle disengaged and the pilots recognized failure of the Airbus A330's speed sensors. The pilots took manual control and the aircraft climbed. A stall warning sounded as the jet ascended rapidly from 35,000 to 37,500 feet and by 38,000 feet three stall warnings had activated. Less than two minutes after the autopilot disconnected, the aircraft was at approximately 35,000 feet, with full takeoff thrust selected; the angle of attack had exceeded 40 degrees and jet was falling at about -10,000 ft/min.

The captain was not present in the cockpit as the incident began. The flight deck crew was flying at night over the ocean near storms where they expected turbulence. What they faced was an aircraft that suddenly disengaged both the autopilot and auto-throttles, and cockpit displays that delivered mismatched and rapidly changing airspeed values that ranged from at least 275 to 60 knots. Within seconds, the non-flying pilot stated, "So we've lost the speeds." Then he said, "Alternate law." Those two words mean, among other things, that the aircraft's angle-of-attack protections have been shut down. Before the captain entered the cockpit, the pitch and angle of attack of Flight 447 had both reached 16 degrees as it was hand-flown. The horizontal stabilizer had passed from 3 to about 13 degrees nose-up. The throttles had been set at full takeoff thrust and the aircraft had stalled. It was less than two minutes since the autopilot had disengaged.

As the captain entered the cockpit, the aircraft's systems received airspeed values they deemed invalid, leading the airplane's systems to automatically shut off the stall warnings. The aircraft was still in full stall with the nose up, falling at -10,000 ft/min. Almost one minute into the stall, the pilots reduced engine thrust and temporarily made nose-down inputs that were not enough to break the stall. As the jet continued to fall, it rolled at times up to 40 degrees and turned more than 180 degrees to the right. Data shows that the pilot flying held the sidestick at the full left and nose-up stops for the entirety of one 30-second span, and that the airliner remained stalled until impact.

There were as many as three pilots in the cockpit through the majority of the descent. The pilot flying as the event unfolded was the least experienced of the crew, with 3,000 hours of flight time. He was right-seat at the time. The flight's captain had almost 11,000 hours of experience. He was not in the cockpit as the incident began. The cockpit crew attempted to call him to the flight deck several times during the first minute after the airspeed sensors failed. He joined them less than two minutes after the autopilot disconnected. A second pilot, flying left seat, was given the controls in the flight's final minute. Aside from that information, BEA, the investigating agency, did not publish any cockpit conversation that took place during the last minute of the flight.

The aircraft impacted the water at 16.2 degrees nose-up with a roll angle of 5.3 degrees to the left. The aircraft heading was 270 degrees (nearly opposite the planned route of flight) and the ground speed was 107 knots. The last recorded vertical speed was -10,912 ft/min.



"Air France crash calls for better pilot training, experts say" WTF!!!

Is this what happens when you have a computer fly the plane 90% of the time and for get the basics??

So if I remember my training. If you loose the air speed indicator just keep flying normal. Attitude indicator, straight and level. Turn coordinator, no turn. VSI 0, Altimeter, steady. Check GPS for ground speed.

This really makes me question how good these pilots were. I know it is not PC to speak ill of the dead but they killed 228 souls who trusted their lives to those pilots.

Regards...Rob

[Littlecub]

Better pilot training needed, experts say
by Alan Levin on May. 31, 2011, under USA Today News

As Air France Flight 447 plunged in the darkness two years ago, its pilots had ample opportunities to save the jet. Instead, as has happened repeatedly on airliners around the world, they exacerbated the problem, according to preliminary information released by French investigators.

The Air France disaster, which killed 228 people on their way from Brazil to France on June 1, 2009, is the latest example — and one of the most deadly — of the biggest killer in aviation: a plane going out of control.

The latest information in the Air France case, released Friday by French investigators, is spurring renewed calls for better pilot training and other measures.

“If this was a technical problem (with the jet), we’d be saying we need to fix this,” says John Cox, a former airline pilot and safety consultant who has written on loss of control for the British Royal Aeronautical Society. “There have been those of us in the industry that have been arguing for this for decades.”

What is needed is better training so pilots are not as startled and confused during emergencies, and better tools to warn them when their planes are about to go out of control, the experts say.

Plummet from the sky

The French government’s preliminary report describes what happened:

The Air France jet’s 7-mile plunge into the Atlantic Ocean began suddenly when the jet’s instruments went haywire. Ice had blocked the jet’s speed sensors; the pilots could not tell how fast they were going. Warnings and alerts sounded almost simultaneously.

In response, the pilots made a series of mistakes, according to the French Bureau d’Enquêtes et d’Analyses, the agency that investigates aviation accidents.

Instead of flying level while they diagnosed the problem, one of the pilots climbed steeply, which caused a loss of speed. Then the aggressive nose-up pitch of the plane and the slower speed caused air to stop flowing smoothly over the wings, triggering a loss of lift and a rapid descent.

They had entered an aerodynamic stall — which has nothing to do with the engines, which operated normally — meaning the wings could no longer keep the plane aloft. Once a plane is stalled, the correct response is to lower the nose and increase speed.

For nearly the entire 3½ minutes before they crashed into the ocean, the pilots did the opposite, holding the Airbus A330′s joystick back to lift the nose.

Although the response was improper, it would be wrong to simply blame the pilots without looking at how well they were prepared for the emergency and whether the information they received could have confused them, says Michael Barr, an instructor at the University of Southern California’s Aviation Safety and Security Program. “They’re sitting there happy, the autopilot is on,” Barr says. “Next thing you know, lights are flashing, warning horns are on. There were probably 10 warnings or messages coming to the crew at the same time.”

Similar miscalculations and miscues have been common in fatal accidents:

•In the Colgan Air crash Feb. 12, 2009, near Buffalo that killed 50 people, the captain overreacted to a warning that the Bombardier Q400 turboprop had gotten too slow and yanked the nose of the plane upward, the National Transportation Safety Board found. If he had pushed the nose down, the board said, he might have saved the plane.

•On Aug. 16, 2005, a West Caribbean Airways Boeing MD-82 crashed in Venezuela, killing all 160 people aboard, after the jet stalled at 33,000 feet. The Venezuelan government blamed the pilots for failing to recognize that they were in a stall during a 3½-minute plunge, despite alerts from the automatic stall warning system.

•On Oct. 14, 2004, a Pinnacle Airlines jet crashed near Jefferson City, Mo., after the pilots stalled the Bombardier CRJ-200 at a high altitude, the NTSB found. Both pilots died; no passengers were aboard.

Similar accidents killed 1,848 people in the 10 years ending in 2009, according to jet manufacturer Boeing.

Limitations of human brain

It may not be possible to prevent all such accidents.

Corporate pilot Patrick Veillette, who is writing a paper on the subject for the International Society of Air Safety Investigators, says there is evidence to suggest that the human brain cannot grasp what is going on in the most severe emergencies.

Still, Cox and others say stall training has been lacking for decades.

Newer flight simulators can better teach airline pilots how planes respond in stalls, and their use should be dramatically increased, they say.

Responding in part to the Buffalo crash, the U.S. Federal Aviation Administration has proposed improving pilot training.

“If we’re going to make sizable improvements in aviation safety, we need to deal with upset recovery,” Cox says. “That’s where the risk is.”

Copyright © 2010 USA TODAY, a division of Gannett Co. Inc.

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EDIT: Please NOTE: This is a NEWS article copied to here for your convenience from USA Today.
Edit by littlecub.

[OregonMaule]

Limitations of human brain

It may not be possible to prevent all such accidents.

When the shit hits the fan, some people shit themselves. Other rise to the challenge and are true heroes.

Chesley Sullenberger comes to mind.

Regards...Rob

[Zzz]

Approaching coffin corner... for the sake of argument, it may not be as simple as you think to hand fly the aircraft at that altitude in IMC + turbulence from TS + inop airspeed.

[OregonMaule]

Approaching coffin corner... for the sake of argument, it may not be as simple as you think to hand fly the aircraft at that altitude in IMC + turbulence from TS + inop airspeed.

For argument sake. I think that Air Bus will fly with an airspeed between 150 KTS and 500KTS The FDR doesn't talk about turbulence. How hard is it to keep the wings close to level and not climbing or descending. I can do that with just the attitude indicator.

Who out there knows, if you got this Air Bus in a stall condition how hard is it to recover it?

Regards...Rob

[Zzz]

I can do that with just the attitude indicator.

Most things are easier in what is essentially a trainer aircraft, and at altitudes less than 10,000. What do you have in your training to deal with say... mach tuck in a CRJ? I don't even know what that is, but it sounds like it has something to do with going really fast and really high. What if your fly-by-wire aircraft isn't reporting the right information to you?

Easy to condemn these guys in hindsight, but I'm sure they'd been in worse weather/aircraft config/emergency situations than most of us and this one still got them. It's not like a regional airline with young inexperienced pilots, this was a transoceanic flight. Of course, everyone blows it sometime.

[Stol]

delete

[z3skybolt]

About 30 years ago....

....the cover story of the ALPA Magazine was..."HERE COMES THE ELECTRIC AIRLINER.

An ALPA pilot/author had been sent to France to interview Airbus and write about the proposed A-320....the "electric airliner".

Late in the article the Airbus engineer was questioned about the sidestick controllers. Concern was expressed that pilots would have difficulty adapting to such a radical change in control presentation.

The Airbus engineer's response? "Captain....you can fly this airplane with your left hand, you can fly it with your right hand, you can fly it with your big toe." "You don't need to fly this airplane at all." "It can fly itself."

Therein lays the rub.

And a bit more about how the sidestick controller works/doesn't work on the Airbus.

What a lousy system!!

Since the side sticks are only "wired", they are not mechanically interconnected like the old conventional planes. The right side cannot feel the movement from the left stick. What happens is that, when there are opposite deflections, their inputs are algebraically added (total sum) with the maximum limit corresponding to the movement of one side stick. If the captain pulls full left, and his copilot pulls full right, the net effect is zero.

So, the last pilot to click on an override push-button on the side stick obtains control (an indicator light in front of the other pilot signals this fact). The potential exists for the pilots to *fight* over the control of the side sticks. Rather than the "strongest" pilot winning, the one with the fastest thumb will win!

Bob

p.s. ALPA is the Airline Pilots Association...a Union.

[m7flyer]

I heard the airbus crew of the future was to be a Pilot and a Dog. The Pilot is there to feed the Dog and the Dog is there to bite the pilot if he tries to touch the controls.

[lownslow79]

I heard the airbus crew of the future was to be a Pilot and a Dog. The Pilot is there to feed the Dog and the Dog is there to bite the pilot if he tries to touch the controls.

Nice! I am going to borrow that! LMAO! Too bad I have to fly an A-340 and another A-330 and yet another A-319 to get home to the U.S. This upcoming July. The only relief is a 747-400 ride (yuck) and then a 757 from LAX to DTW (Ah, relief).

[EZFlap]

The French authorities convened an investigation into Flight 447, and determined that it was the fault of the Americans.

Seriously, my condolences to the families of all those on board. I hope that there is a technical or operational solution to this issue so it cannot claim any more lives. Gyro or motion sensor backup, talking to the flight computer, or something.

[born2flyak]

When any of the Cessnas I fly stall, you have to wonder. The nose kinda wallows and drops a few degrees and life goes on. When the Cherokee 6's stall, you've also reached the end of the runway, cruise speed, and L/D-max so everything is hunky-dory. The whole thing sways side to side like a leaf in the wind. I'd hate to fly anything much bigger that has the same characteristics... Must be a high-wing/low-wing thing...

[Littlecub]

SOURCE:Air Transport Intelligence news
Air France highlights evidence of technical problem on AF447
By David Kaminski-Morrow

Air France has emphasised the evidence of a technical malfunction on the Airbus A330 which crashed in the South Atlantic two years ago, after French investigators detailed the final minutes of flight AF447.

Preliminary information shows that the aircraft climbed and stalled at high altitude, and that the crew failed to recover from the stall before the A330 struck the ocean surface.

France's Bureau d'Enquetes et d'Analyses confirmed there was a sudden change in displayed speeds and that there was a discrepancy between that shown on the primary flight display and that on the standby instrument system.

The non-flying pilot said that the aircraft had "lost the speeds" and then mentioned that the aircraft had switched into 'alternate' law - a normal response from the aircraft in the event of unreliable speed information.

BEA does not mention any reason for the inconsistent speed indications.

But Air France said: "It appears...that the initial problem was the failure of the speed probes which led to the disconnection of the autopilot and the loss of the associated piloting protection systems, and that the aircraft stalled at high altitude."

The airline does not discuss the crew's response to the stall beyond pointing out that the captain, having left the cockpit to rest, quickly returned to address the situation.

"The crew, made up of three skilled pilots, demonstrated a totally professional attitude and were committed to carrying out their task to the very end and Air France wishes to pay tribute to them," said the carrier.

"All the data collected must now be analysed. It will only be at the end of this complex task, which requires patience and precision, that the BEA will be able to establish the causes that led to the disaster."

Airbus has issued only a limited response to the AF447 update, in which it said the BEA's information "constitutes a significant step towards the identification of the complete chain of events".

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He said/She said.......
Air France doesn't want the pilots to be blamed......
It isn't all sorted out yet......(says AF)
lc

[OregonMaule]

He said/She said.......
Air France doesn't want the pilots to be blamed......
It isn't all sorted out yet......(says AF)
lc

Very admirable that the company is standing behind their pilots. Usually the company are the first to throw them under the bus.

Good day even though it is gray and rain here.

[GlassPilot]

I flew to the keys a few days ago in a friends CJ-4 Citation Jet.... We cruise at 45 thousand feet and the range between VNE and stall speed is just a few Knots... It is a VERY narrow window to navigate safely......

Ps... The view from up here is tremedous...

Ben.

These guys started at FL350 and hand flew it to FL380 before the stall. Even if fully loaded I don't think coffin corner would be an issue at the beginning. Obviously the stall side of the coffin corner became an issue but it seems that was self imposed.

[DCO-65]

Can they move fuel aft on those aircraft to get a more efficient center of gravity?

[porterjet]

Mach Tuck: Here is the first paragraph from the wikipedia article;
"Mach tuck is the result of an aerodynamic stall due to an over-speed condition, rather than the more common stalls resulting from boundary layer separation due to insufficient airspeed, increased angle of attack, excessive load factors, or a combination of those causes. As the aircraft's wing approaches its critical Mach number, the aircraft is traveling below Mach 1.0. However, the accelerated airflow over the upper surface of the cambered wing exceeds Mach 1.0 and a shock wave is created at the point on the wing where the accelerated airflow has gone supersonic. While the air ahead of the shock wave is in laminar flow, a boundary layer separation is created aft of the shock wave, and that section of the wing fails to produce lift."
As the indicated Mach number increases beyond critical mach the separation becomes so severe the autopilot and elevators can no longer hold the nose of the aircraft level and a fairly pronounced nose down pitching occurs.

Coffin corner, again from wikipedia;
"The coffin corner (or Q corner) is the altitude at or near which a fast fixed-wing aircraft's stall speed is equal to the critical Mach number, at a given gross weight and G-force loading. At this altitude the airplane becomes nearly impossible to keep in stable flight. Since the stall speed is the minimum speed required to maintain level flight, any reduction in speed will cause the airplane to stall and lose altitude. Since the critical Mach number is the maximum speed at which air can travel over the wings without losing lift due to flow separation and shock waves, any increase in speed will cause the airplane to lose lift, or to pitch heavily nose-down, and lose altitude. The "corner" refers to the triangular shape at the top right of a flight envelope chart where the stall speed and critical Mach number lines come together."

In the case of Air France, IMHO, since they were able to climb to FL 380 before stalling they were nowhere near the coffin corner at FL 350.
It is conceivable that, at night, in turbulence with thunderstorms in close proximity and a sudden loss of reliable airspeed which also kicked off the autothrottles they thought they were in a mach tuck situation rather than a slow speed stall. If you remember the Captain returned to the flight deck and retarded the throttles which is the correct action for mack tuck. Unfortunately they apparently never realized they were in a slow speed stall and not a mach tuck situation.

[nmflyguy]

Mach Tuck: Here is the first paragraph from the wikipedia article;
"Mach tuck is the result of an aerodynamic stall due to an over-speed condition, rather than the more common stalls resulting from boundary layer separation due to insufficient airspeed, increased angle of attack, excessive load factors, or a combination of those causes. As the aircraft's wing approaches its critical Mach number, the aircraft is traveling below Mach 1.0. However, the accelerated airflow over the upper surface of the cambered wing exceeds Mach 1.0 and a shock wave is created at the point on the wing where the accelerated airflow has gone supersonic. While the air ahead of the shock wave is in laminar flow, a boundary layer separation is created aft of the shock wave, and that section of the wing fails to produce lift."
As the indicated Mach number increases beyond critical mach the separation becomes so severe the autopilot and elevators can no longer hold the nose of the aircraft level and a fairly pronounced nose down pitching occurs.

Coffin corner, again from wikipedia;
"The coffin corner (or Q corner) is the altitude at or near which a fast fixed-wing aircraft's stall speed is equal to the critical Mach number, at a given gross weight and G-force loading. At this altitude the airplane becomes nearly impossible to keep in stable flight. Since the stall speed is the minimum speed required to maintain level flight, any reduction in speed will cause the airplane to stall and lose altitude. Since the critical Mach number is the maximum speed at which air can travel over the wings without losing lift due to flow separation and shock waves, any increase in speed will cause the airplane to lose lift, or to pitch heavily nose-down, and lose altitude. The "corner" refers to the triangular shape at the top right of a flight envelope chart where the stall speed and critical Mach number lines come together."

In the case of Air France, IMHO, since they were able to climb to FL 380 before stalling they were nowhere near the coffin corner at FL 350.
It is conceivable that, at night, in turbulence with thunderstorms in close proximity and a sudden loss of reliable airspeed which also kicked off the autothrottles they thought they were in a mach tuck situation rather than a slow speed stall. If you remember the Captain returned to the flight deck and retarded the throttles which is the correct action for mack tuck. Unfortunately they apparently never realized they were in a slow speed stall and not a mach tuck situation.

John - interesting analysis, and the performance you describe is obviously way beyond the kind of aviating I'm trained to deal with in a light single engine prop aircraft.

Dumb question (??) - whether in a mach tuck situation, or near the coffin corner of the flight envelope, is it still true that in order to end the stall, regardless of airspeed or attitude, the angle of attack has to be reduced to below the critical angle of attack?

No matter what the answer, it just seems completely incredible that three experienced ATPs would believe that there is any part of any fixed wing aircraft's flight envelope in which it makes sense to pull the stick all the way aft to the stops and leave it there for three and a half minutes. It almosts sounds like they simply went nuts up there on the flight deck of that poor aircraft.

Duane

[nmflyguy]

One other question to ponder - am I missing something, but aren't all airline pilots, especially the flat-footed guys flying the heavy iron, required to demonstrate their ability to fly partial panel in order to pass their periodic check rides? And to deal with multiple in-flight emergencies?

It seems that even with the airspeed indicator frozen, and maybe with the AOA out of service and all manner of bells and alarms going off on the flight deck, the pilots still had plenty of instruments available to tell them what the airplane was really doing ... they still had the attitude indicator, the altimeter, the turn indicator and DG - or whatever AHRS backup intruments were installed in that panel - and the engine controls. Plus they had the GPS to give them ground speed. Seems like they had plenty of performance indicators to tell them that continuously pulling back on the stick was the wrong thing to do (even if that wasn't patently obvious just from an understanding of basic aerodynamics).

Sure, as Zane points out, turbulence can beat the heck out of you and make it dificult to concentrate on a partial panel, but that's why emergency response training is so necessary, for all pilots and especially those entrusted with hundreds of souls on a big airliner. Fancy electronic controls do not substitute for such training.

Perhaps in this instance, the turbulence may have simply caused the pilots to panic ... panic seems to be a fairly plausible explanation for failing to read and use the available flight instruments and reasonably manipulate the flight controls ... because once panicked, the brain basically shuts down.

We'll never know what was going through their heads on the way down to the ocean.

Bottom line, if the news reports are accurate (???), then there is no good excuse for doing what those pilots did to kill hundreds of their trusting passengers and themselves in a perfectly airworthy airplane. If that kind of statement is deemed "judgmental", then so what? If professional pilots can't be held to account for the lives of their innocent passengers, then nobody is accountable for anything in life.

Duane

[OregonMaule]

Total layman on this but it doesn't sound like the AB was in a spin.

It seems so simple and stupid to say it was just a nose high stall and all they needed to do was lower the nose. It looks to me that would have fixed the stall problem. It seems like a big version of the Maule stall or falling leaf stall where it was mushing down at 10000FPM. The ground speed was 107KTS.

It looks like they just lost it mentally. I think I read in one of the reports the word "stall" was never heard on the cockpit voice.

Since Air France won't release the cockpit voice it just adds to the mystery and has the feel of a cover up. I'll bet what ever is on the cockpit voice wouldn't be good for Air France in a business since. I would like to be a fly on the wall in the Air France safety office to hear what they are really talking about. Very sad.

Regards...Rob