Going to the Land Waaaaay Down Under

Which means my posting, already not making up in quality what it lacks in frequency, will likely do a very good imitation of nil for the next several weeks.

Cause, Meet Effect II

From an editorial in today's NYT:

The gun lobby, fairly crowing, claims the spike in gun sales is because more people are feeling the need to protect themselves — even though the latest F.B.I. data show a 6 percent drop in violent crimes.

Huh?

Nervous flyers should not watch this.

Gee, I wonder why?

I'm going on a trip in January, about which I got a notice from the company:

[There is] a new Department of Transportation policy that goes into effect in 2012. It requires that government taxes and fees be reflected directly in air fare prices—instead of being listed separately and added to a trip price.

The correct word, by the way, is buried.

This is not a good sign

Toto, we are so not in Kansas

Reading todays Sunday Times, I came across the classifieds. The matrimonial classifieds. Perhaps I should mention at the outset it is the Times of Delhi at which I am gandering. Here a couple, out of a couple hundred, that caught my eye:

High Status South Delhi based industrialist Punjabi Arora family seeks alliance for their beautiful, fair, slim, charming, cultured Daughter. '81 born/5'5". Convent educated post graduate from most reputed Institute of Economics from London.

Looking for handsome, qualified, well settled in Business/Industrialist boy.

Caste no bar.

How nice.

On the flip side of this coin,

High Profile industrialist and multiple business Punjabi Saraswat Brahmin family invites alliance for their son, Manglik. Vegetarian, teetotaler, 5'7"/Sept 86/BBA from USA well settled in family business. Looking fro professionally qualified beautiful girl from similar status family.

Wondering: is caste a bar a bar to caste no bar?

Among the brides wanted section, the physical descriptions of the hopefuls rarely amounted to anything more than height and DOB.

Those seeking grooms are always a little more elaborate, adding at least a couple references looks, build, personality and sophistication. However, since the women are, a la Lake Wobegon, all either beautiful or very beautiful and slim and charming and sophisticated, these additional qualifiers are very little help. (Okay, I did find one that is homely and slim.)

Along that adjectival stream, roughly 70% of them plugged in either "fair" or "very fair".

None of the men seeking wives felt compelled to share in that regard.

Unsurprisingly, I suppose, not one ad noted either hair or eye color.

I'll bet there are a few lessons on human nature to be had here.

Nice Folks

ODL's contribution to political discourse.

An Eric's Progress*

The man-child just made Eagle Scout.

---

*h/t Brit

Crash starts with CRA

This is an extension of Stating the Obvious.

During the four years that have elapsed since Homeaggedon, you would think there would be some consensus around its causes. No, I don't mean the obvious one: all bankers are the unremitting, Snidely Whiplash personifications of total evil. Rather, whether there was some systemic element that ensured a housing bubble replaced the preceding secular trend in housing prices while virally undermining our economy.

Pace the MAL, there is a principal cause that by its very nature had to engender the worst recession in 60 years. Even worse, that cause came about only due to a breathtaking combination of stupidity, wishful thinking, untreatable ignorance and, in at least one case, destructive intent.

I am talking, of course about the Community Reinvestment Act.

The CRA was offspring of two seeming truisms. First, bankers were happy to take deposits from anywhere, but were racistly reluctant to lend in minority neighborhoods. Second, because home ownership is so strongly correlated with stable, law-abiding neighborhoods, government policies must step in where the market was so obviously failing.

Even taking those seeming truisms as given, analytical effort falling well short of mental exhaustion is sufficient to see the crater at which the CRA must arrive (as well as ascertain the MAL's, and ODLs', pervasive reality distortion field).

Since rascist bankers won't lend to the melanin gifted, they must be first urged, then increasingly forced, to do so in the face unyielding racism, as evidenced by the continuing reluctance to lend. But that means that money-grubbing bankers eager to make a profit wherever they can, must be first urged, then increasingly forced, to lend despite poor or non-existent credit ratings, limited employment history, and non-existent down payments.

Of course, bankers have always been willing to lend to people bearing those unfortunate stigma, but at a price: interest rates that reflected the associated higher default risk.

This is where, right at the beginning, the crash became inevitable. See if you can follow along; it really isn't too tough:

• Homeownership is an unalloyed good.


• Racist profiteering bankers willfully underserve challenged neighborhoods.


• The lack of employment history and savings is unrelated to default risk.


• Therefore, bankers must be encouraged to overcome their unwillingness.


• When enouragment proves insufficient, coercion follows and erosion follows.


• Coercion takes the form of congressional intervention in banking business decisions, based upon compliance.


• Erosion takes several forms: elimination of downpayment requirements, employment and credit history.


• The underlying presumption is (pick one or more) [extremely racist | a perfect example of magical thinking | fully intended to undermine the banking system].


• Racist, because melanin gifted populations with otherwise identically risk enhanced financial characteristics are not nearly as likely to default as their melanin challenged counterparts. (As it turns out, the Boston Fed, through through the kind of incompetence and mendacity that is always accompanied by the modifiers "monumental" and "criminal" directly abetted that preposterous conclusion.)


• Magical, because it required believing a simple, government imposed, solution could possibly solve a much more complex problem that by its very nature had to lie beyond congressional fiat.


• There were some who both advocated the CRA, and hoped for its intended effect. (Note: this isn't part of the logic train, but rather an unanticipated consequence of looking into how inevitable the crash was.)


• In order for the CRA to function (a goal hoped for by the drooling lackwits of both parties), the following had to happen:
  
  
  • A vast expansion of GSEs and the secondary market.
  
  
  • Bundling of mortgage backed securities.
  
  
  • The hiding of high risk mortgages within those bundles

In short, the route from CRA to crater was so direct as to resemble the shortest, and most obvious, distance between points. It was a route that would never have been traveled without (mostly) well-intentioned idiots (Dodd, Frank, Clinton, Bush) forcing decisions that would never have occurred otherwise.

It is odd — okay, maybe it isn't — that the inchoate, incoherent, ill-educated (or wholly ineducable) flocks that comprise the ODLs never once mention the pivotal role that the CRA had in creating our crater. Just as no one seems to mention the Greek government, or the European Union, for the string of staggering stupidities that led them to their own perfectly foreseeable smoking hole.

Instead, it's all on Snidely.

---

It will take awhile to read these, but your time will be rewarded. Presuming, that is, you find being appalled rewarding:
Anatomy of Trainwreck: Causes of the Mortgage Meltdown
The Community Reinvestment Act, Evaluated
The Community Reinvestment Act's Harmful Legacy

Been there, seen that

I'm in San Francisco today, staying right next to Fisherman's Wharf, and a mile and a half or so from Occupy San Francisco.

In as much as it is a nice, if slightly cool day, I decided to assign the Daily Duck's crack San Francisco I'mwitless News Team (me) to some in person on the front lines reporting.

The occupation covers a small park 100 by 300 yards alongside the Embarcadero, and consists largely of large plastic tarps haphazardly providing top cover for REI castoff tents. The Occupation seems determined to deplete the world's supply of ugly signs. They run the gamut from inchoate to incoherent, with more than a dash of illiterate. Only one I saw made a lick of sense: "Don't Piss Here."

As for the oppressors, there were two police officers strolling around looking both very professional and completely bored.

Of course, this being the Wharf and Embarcadero, and a nice day, tourists abound. Not one of whom, even if pressed on the subject, could possibly give the appearance of caring even less about the Occupation than they already did.

A friend of mine who lives in the area says the Occupation leads the local news every night. It is no more apparent to him than to me as to why this should be so.

What is readily apparent though, is that anyone seeing even the slightest similarities between Occupy [anyplace with a lawn available for complete destruction] and the Tea Party, other than that both groups are bipedal, is either delusional or lying.

R*cist B*st*rds

Slate has a story noting, with some astonishment, the current popularity of Herman Cain with conservatives and Tea Party members.

The bafflegabment is easy to understand; after all, if the Tea Party is about anything, it is about racism, right?

Well, as it happens, there is some comforting news for the true believers:

But maybe the Tea Party shouldn’t be so cheery, says Christopher Parker. He’s an associate professor of political science at the University of Washington. In 2010, he was the lead investigator on an academic study of the Tea Party and race. The academics surveyed 117 “true believers” of the movement, alongside hundreds of “true skeptics,” people with mixed opinions, and people who didn’t know about the movement. Parker found that Tea Partiers held generally more negative views of blacks and Hispanics, measured in a number of ways.

One of Parker’s test statements was: “Irish, Italians, Jewish, and many other minorities overcame prejudice and worked their way up. Blacks should do the same without special favors.” Seventy percent of all white people in the study agreed; 88 percent of Tea Partiers agreed. Another statement: “If blacks would only try harder they could be just as well off as whites.” Fifty-six percent of all white people agreed, and 73 percent of Tea Partiers. These are the kind of sentiments that Cain has voiced as he’s been asked about race. “He has an inspiring story,” says Parker. It doesn’t change the study’s conclusions.

Yep, no doubt about it, denying the bigotry of low expectations is the sure sign of fuming racism.

One-oh-Wonder

Shut Up and Color

The experts agree: AGW is big, it's bad, and it is coming soon to a biosphere near you.

According to Gary Gutting, professor of philosophy at Notre Dame, that means the rest of us have no option other than deference.

How can we, nonexperts, take account of expert opinion when it is relevant to decisions about public policy?

To answer this question, we need to reflect on the logic of appeals to the authority of experts.  First of all, such appeals require a decision about who the experts on a given topic are.  Until there is agreement about this, expert opinion can have no persuasive role in our discussions.  Another requirement is that there be a consensus among the experts about points relevant to our discussion.   Precisely because we are not experts, we are in no position to adjudicate disputes among those who are.  Finally, given a consensus on a claim among recognized experts, we nonexperts have no basis for rejecting the truth of the claim.

These requirements may seem trivially obvious, but they have serious consequences.  Consider, [AGW].  All creditable parties to this debate recognize a group of experts designated as “climate scientists,” whom they cite in either support or opposition to their claims about global warming.

The corporate view among climate scientists, outliers notwithstanding, is that Gaia is getting hot under the collar, and human activity is responsible for this onslaught of fever. Sure, there is some expert dispute, but since the consensus has decided upon AGW, and we non-experts are in no position to arbitrate, then it is crayons for us.

As long as [non-experts accept there is such a thing as expertise in climate science], they have no basis for supporting the minority position.  Critics within the community of climate scientists may have a cogent case against A.G.W., but, given the overall consensus of that community, we non-experts have no basis for concluding that this is so.  It does no good to say that we find the consensus conclusions poorly supported.  Since we are not experts on the subject, our judgment  has no standing.

From this it follows that non-experts, hereafter referred to as The Great Unwashed Masses (TGUMs), cannot argue against The Consensus; instead, those among the TGUMs who dispute AGW must argue that:

… climate science lacks the scientific status needed be taken seriously in our debates about public policy.  There may well be areas of inquiry (e.g., various sub-disciplines of the social sciences) open to this sort of critique.  But there does not seem to be a promising case against the scientific authority of climate science.

So, to summarize:

Once we have accepted the authority of a particular scientific discipline, we cannot consistently reject its conclusions.  To adapt Schopenhauer’s famous remark about causality, science is not a taxi-cab that we can get in and out of whenever we like.  Once we board the train of climate science, there is no alternative to taking it wherever it may go.

In other words, Shut Up and Color.

But does this conclusion follow?

On the face of it, contradiction should be hard to come by. After all, Dr. Gutting as a philosopher is a certified expert in constructing philosophical arguments. By definition, his expert argument on the expertise of experts must be immune to the inept pesterings of a TGUM.

His insistence upon accepting the consensus of experts does seem to accord reasonably well with experience. We take our cars in to mechanics — experts in the science of car repair — and rarely contradict their opinions on which framitz needs defargging. Similarly, faced with some significant malaise, people routinely get a second, or even third doctorial opinion; should those opinions coalesce into consensus, then we assume whatever position is required, and take what medically expert consensus sends our direction. The list goes on nearly without end: deference to physicists, accountants, and geologists in the realms of physics, making sense of IRS regulations and where to drill for oil goes without saying.

Therefore, failing to defer to climate scientists must be a singular case of irrationality.

Unless, of course, our expert philosopher has created an argument that assumes, conceals, neglects, or is ignorant of, rather a lot.

He assumes that since climatologists are doing sciency things, their product is science. However, in order for a hypothesis to qualify as a scientific theory, it must have deductive consequences. For example, a deductive consequence of naturalistic evolution is that inheritance must be particular, not blended. Unfortunately, climate science is so devoid of deductive consequences that it explains everything. In so doing, it is indistinguishable from religion: by explaining everything, it actually explains nothing.

Going one long step further, he also assumes (although implicitly insists is probably closer to the mark) that climate science is so arcane that its content is beyond the ken of TGUMs. This insistent assumption is striking. I have a book that convincingly explains relativity to TGUMs, thereby justifying its experts. Surely, climate science can't be more difficult to apprehend than the singular intellectual accomplishment of the modern era.

Then there is the matter of judging the experts' performance. If my mechanic tells me my framitz is fargged, when all along the wishbone was whacky, then his expertise is something less than total. Except as a contrived exercise in post hoc reasoning, climate scientists routinely fail to meaningfully predict actual climate trends. That alone is no source of comfort; after all, they could be wrong in not being right enough. However, their predictions have, at best, uniformly exceeded subsequent observations. Harold Camping assured us the apocalypse was to happen on May 21st. In the late 80s, Dr. Hansen assured us that NYC's West Side Highway would be underwater by now. Based upon the evidence, I have no more reason to suspect that Dr. Hansen's expertise in climate science is any more elevated than Harold Camping's is in apocalypse science.

TGUMs have no need to acknowledge expertise simply because a self anointed group claims it for themselves. Rather, deferring to that claim, when reality has so relentlessly contradicted it, and the costs of doing so, both in terms of economics and freedom, are so high would be irrational folly of the first order.

Dr. Gutter's insistence on our submission to the god of consensus isn't philosophy, it is theology.

Oh, by the way, stay inside the lines. Or else.

Cause, meet Effect

From today's NYT Op-Ed The Misuse of Life Without Parole:

From 1992 to 2008, the number in prison for life without parole tripled from 12,453 to 41,095, even though violent crime declined sharply all over the country during that period.

Huh?

Stating the Obvious

For those who can't determine the link between the CRA and the collapse of the housing market, look here (read it in its entirety):

The data shows that the principal buyers [of almost 25 million subprime and other nonprime mortgages—almost half of all U.S. mortgages] were insured banks, government sponsored enterprises (GSEs) such as Fannie Mae and Freddie Mac, and the FHA—all government agencies or private companies forced to comply with government mandates about mortgage lending. When Fannie and Freddie were finally taken over by the government in 2008, more than 10 million subprime and other weak loans were either on their books or were in mortgage-backed securities they had guaranteed. An additional 4.5 million were guaranteed by the FHA and sold through Ginnie Mae before 2008, and a further 2.5 million loans were made under the rubric of the Community Reinvestment Act (CRA), which required insured banks to provide mortgage credit to home buyers who were at or below 80% of median income. Thus, almost two-thirds of all the bad mortgages in our financial system, many of which are now defaulting at unprecedented rates, were bought by government agencies or required by government regulations.

No surprise, really. The logic of the CRA ensured this outcome to anyone more sentient than Barney Frank.

TDD Readers Already Know This

Aircraft automation may be eroding pilots' skills

WASHINGTON — Pilots' "automation addiction" has eroded their flying skills to the point that they sometimes don't know how to recover from stalls and other midflight problems, say pilots and safety officials. The weakened skills have contributed to hundreds of deaths in airline crashes in the last five years.

Fifty-one "loss of control" accidents occurred in which planes stalled in flight or got into unusual positions from which pilots were unable to recover, making it the most common type of airline accident, according to the International Air Transport Association.
"We're seeing a new breed of accident with these state-of-the-art planes," said Rory Kay, an airline captain and co-chair of a Federal Aviation Administration advisory committee on pilot training. "We're forgetting how to fly."
Opportunities for airline pilots to maintain their proficiency by manually flying planes are increasingly limited, the FAA committee recently warned. Airlines and regulators discourage or even ban pilots from turning off the autopilot and flying planes themselves, the panel said.

Hmmm. I think I remember something about this a month and a half ago.

If the training environment reflected [an automation driven] culture, then training would tend to emphasize flying through the Flight Management System. The consequence could be pilots who are very good at translating required performance into FMS commands, but who have completely lost sight of the essential relationships involved in obtaining desired performance.

The article is pretty good the concepts, and does reasonably well on the details. Regulations have effectively banned hand flying the aircraft above FL270 (approximately 27,000 feet) over the last six or so years; however, that is a realm where hardly anyone hand flew previously. Airlines vary in their approach to automation, both among themselves and over time. When I was at Northwest, the operations manual actively encouraged turning off all automation when conditions were permissive. My current airline used to actively discourage shutting off the Flight Management System and the Auto Thrust System (ATS). It has now gone the opposite direction.

Some mishaps that the article lumps under eroded pilot skills are really failure to monitor performance, which is probably more a consequence of complacency. Just over two years a Turkish Airlines 737 crashed short of the runway at Amsterdam Schiphol. A malfunctioning radar altimeter feeding bad data to the ATS, causing it to command idle thrust. The flight crew failed to notice the 60 knot airspeed decay over more than a minute and a half. The Captain's response to the stall warning was quick and correct, but there was insufficient altitude remaining to effect a recovery.

If They were to ask me, which They won't, I would tell Them to include various autoflight system failures in both initial and recurrent training (my airline's recurrent training has added much more manual flying to recurrent training, but there are no AFS failure scenarios). While They are at it, They need to add a currency requirement for completely manual arrivals (AP and ATS off, FMS off on the flying pilot's side).

Steam gauge airplanes separated pilots from the pedestrians. It is time to turn up the steam.

Bear Blogging

Today The Volokh Conspiracy posts a couple bear photos taken at Yellowstone.

So, in that spirit, here are a couple close-ups from last week, when Rusty the Alaskan Wilderness Adventure Dog put a bear and her cubs up a tree in our backyard:





Unfortunately, she shows signs of habituating to humans.

AF447 — A Bad Attitude

Previously, in Air France 447 — Summarizing the Summary, I outlined the mishap sequence, and related how a combination of unknowingly inadequate pitot probe design and testing allowed the possibility of complete loss of airspeed sensing due to icing.

All of which leaves completely untouched a fundamental question. How does the complete loss of airspeed indications cripple an aircraft?

Short answer: it doesn't.

(Note: the following was extremely difficult to write, because the conclusions I have drawn are extremely unpleasant. If my tone seems unduly harsh, particularly considering I am speaking of the dead, that is unfortunate, but unavoidable.)

Immediately after AF447's pitot probes iced over, the autopilot shut itself off, the fly-by-wire flight control system (FBW FCS) degraded to alternate law. (Alternate law is the first level of A3xx FCS degradation. The main differences between Normal and Alternate laws are the latter's lack of flight envelope protection -- which means the airplane can be flown into a stall -- flight management system (FMS), autopilot and auto throttles.) Which means that the pilots were left hand flying an airplane with fully functional engines, flight controls, attitude indicators, altimeters, and vertical speed indicators, but without any direct way of knowing that thing responsible for creating distance between dirt and plane; namely, how fast it is going through the air.

The Pilot Flying's (PF) (In the big airplane world, the two pilots have sharply delineated duties. The PF, as the term indicates, is responsible for maintaining aircraft control, directing configuration changes, and calling for checklists. The other pilot is referred to as the Pilot Monitoring (PM), and is responsible for communications, flight plan, executing checklists, FMS inputs other than during cruise, and monitoring aircraft performance. While ultimate decision authority always rests with the Captain, typically the Capt and First Officer will alternate PF and PM on each leg during a trip.) response was to increase pitch attitude to at least twice that possible for sustained flight at FL350, resulting in a climb rate far exceeding available excess power.

(In the airplane I fly, the first two steps for loss of airspeed are turn off the autoflight system then stabilize pitch and power at normal cruise values.)


In other words, the PF was trading airspeed for altitude, until the airplane no longer had any speed to give. At this point, the airplane is at the stall angle of attack (AOA), which is the angle between the wing and relative wind that produces maximum lift. Cruise AOA is roughly 2-3 degrees; stall AOA is about 22 degrees. Approaching stall AOA, drag dramatically increases.

At high altitude, there is only one way out of this: down. Because the airplane was so far into the region of reverse command (AKA being behind the power curve), the PF needed to set the pitch attitude at 5 - 10 degrees below the horizon, select max power, and sacrifice altitude in order to regain airspeed. Instead, the PF drove the elevator to the maximum nose up position and flew the airplane into an aft stick stall, characterized by very low forward speed and extremely high rate of descent.

Then did nothing about it.

All this time, the PM did not note the wildly excessive pitch attitude, unsustainable climb rate, or the gross altitude deviation. Even passing through 10,000 feet, after having lost four miles of altitude, and having mentioned that salient fact, the pilots completely failed to apply any control or power inputs to break the glaringly apparent stall.

The available evidence points in one direction: pilot error of such magnitude as to defy explanation.

There are some contributory factors.

FBW FCSs have their advantages, but one thing they do not provide is aerodynamic feedback. An Old School FCS (OS FCS) is "speed stable", which means the flight controls, all other things being equal, will get very heavy in the nose down direction with a significant loss of airspeed. By the time AF447 reached stall AOA, an OS FCS would have had something like 70 pounds of nose down control forces. In contrast, with a FBW FCS there is no feedback whatsoever of changing airspeed into the flight controls. A FBW FCS is, all things considered, better than an OS FCS when everything is working. However, should multiple system failures put the FCS into a degraded mode, a FBW FCS has no inherent self correction.

[IMHO] Adding to the debit side of the ledger is the "pilot out of the loop" problem that has come along with the "glass-cockpit" territory, regardless of FCS type. Prior to roughly the mid-1980s, aircraft cockpits had "steam gauges", round dial electromechanical indicators, and did not have flight management systems worthy of the name. Steam gauge instrument flying, done well, requires a high-rate observe / orient / decide / act (OODA) loop: observe airspeed, heading, and vertical speed / orient those observations with respect to desired parameters / decide what changes in power and attitude are required to eliminate the difference between observed and desired parameters / move the flight controls and power levers as required.

Glass cockpits come with very capable FMSs, which led many flight departments (including, until a year or so ago, the one at the company for which I work) to essentially require use of the flight director except in very abnormal circumstances. Relying on a flight director makes the OODA loop a pointless exercise. No need to decide on attitude and power, just center the pitch and bank steering bars; it is a task even a modestly gifted monkey can manage.

But wait, there's more. Transport category aircraft completely exclude the most fundamental parameter of them all: wing AOA. Yes, the ATC system is very much like a conductor and a symphony orchestra, where airspeed stands in for rhythm. Since, for a given airspeed, AOA varies based upon weight and configuration, having a bunch of airplanes flying around at their individual optimum AOAs won't work. But, for pete's sake, if the FMS is smart enough to know airspeed is unreliable, the least it can do is replace it with an alternate means of determining speed. One which, BTW, is far less prone to icing, and is mechanically far simpler, than air pressure sensing.

So. FBW airplanes are perfectly happy to run out of airspeed right when knowing airspeed is impossible. Glass cockpits can turn piloting into monkey business. Airliner design and pilot training, no matter how much ingenuity was brought to bear, could more thoroughly ignore an alternate means of determining airspeed.

Does all that suffice to explain putting an otherwise completely flyable airplane into a deep stall, then riding it in?

No.

Using Sherlockian reasoning -- having eliminated the impossible, whatever remains, however improbable, must contain the explanation -- the only alternative left is sheer incompetence. A flight deck with three ostensibly fully qualified pilots were incapable of maintaining basic aircraft control in a situation that, had they done nothing more than stare with gobsmacked amazement we would never have heard about.

[/IMHO]

To an even greater extent than the sea, the sky is incredibly unforgiving of any human carelessness, incapacity, or neglect.
-- unknown

Huh? Wot?

Am I alone in being, until today, completely unaware of Casey Anthony?

Air France 447 — Summarizing the Summary

Warning: For those with an aversion to aviation esoterica, or a low boredom threshold, proceed no further.

(Go here and here for TDD's two previous posts on AF447.)

It took two years since the AF447 smashed into the middle of the Atlantic to find its surprisingly well preserved digital flight data recorder (DFDR) under nearly 13,000 feet of water, but only a matter of weeks to arrive at some preliminary findings.

I am going to present this in two parts, the first summarizing and translating the factual elements of the preliminary report relevant to those who want to know what happened, while being less concerned about how they got to what, or background details not specific to AF 447. (The next post will concentrate on the why behind the what. Inevitably, it will be more speculative.)

What follows is distilled from 150 pages, all the while hoping not to create more questions at the end than readers arrived with.

• AF 447 was operating at FL350 (approximately 35,000 feet), Mach 0.82, with a pitch attitude of 2.5 degrees. These are normal cruise parameters.


• The crew altered course 12 〫 left to avoid weather, and slowed to Mach 0.80 due to turbulence (the standard turbulence penetration airspeed, used whenever the subjective estimate of turbulence exceeds "light".)


• Two minutes later, roughly simultaneously, the autopilot and autothrust disengaged and the airspeed on the primary flight display went from 275 to 60 knots. Then airplane began to roll right, followed by the PF (pilot flying) making a left nose-up input. Shortly thereafter, the airspeed on the standby instrument system also failed.


• Because of the lost airspeed reference, the aircraft reverted to the Alternate Law mode of the fly-by-wire flight control system. This mode provides no envelope (pitch attitude / angle of attack) protection. Stall warning is available, but in a degraded mode. Without valid airspeed, the flight control system assumes a speed of Mach 0.3, and generates a stall warning angle at a 10 degree angle of attack.


• The airplane's pitch attitude continued to increase beyond 10 〫 and the airplane started to climb. Vertical speed reached 7,000 feet per minute until dropping to 700 fpm as the aircraft slowed. Roll angle varied between 12 〫 right and 10 〫 left. After roughly one minute, the aircraft reached 37,500 feet, and the primary airspeed suddenly went from 60 knots to 215 knots and M 0.68. Angle of attack (AOA) was 4 〫.


• The stall warning then triggered again, with an AOA of 6 〫 and increasing. The horizontal stabilizer, which controls pitch, went from 3 〫 to 13 〫 over the next minute, and remained there until impact.


• Fifteen seconds later, the standby airspeed returned and was consistent with primary airspeed. The airplane reached 38,000 feet with pitch attitude and AOA being 16 degrees.


• At this point, the very high induced drag attending high AOA caused a rapid loss of airspeed and, without any pitch correction from the PF, there was a further increase in AOA to 40 degrees and descent increased to 10,000 feet per minute. To visualize this, hold a pencil with the tip roughly 15 〫 above horizontal, then move the pencil downward at an angle 40 〫 below horizontal. The aircraft had several roll oscillations reaching as much as 40 〫, after which the PF made an input to the left and nose up stops lasting 30 seconds.


• About thirty seconds after the aircraft entered its terminal descent, both the PF and the Pilot Monitoring said they had no more indications, and the throttles were placed in idle.


• About fifteen seconds later, the PF made some pitch-down inputs, AOA decreased, speeds became valid, and the stall warning resumed. However, while the AOA decreased, the pitch input was insufficient to unstall the wings


• After thirty more seconds, the PF said "We are going to arrive at [10,000 feet]."


• Fifteen seconds later, both pilots made control inputs, then the PF said to the other pilot "go ahead, you have the controls."


• The aircraft hit the water four minutes and thirty seconds after the initial loss of airspeed. The last recorded aircraft parameters were a descent of 10,900 feet per minute, ground speed of 107 knots, and pitch attitude 16.2 〫 nose up. During the mishap sequence, the aircraft heading changed 260 〫, from roughly 010 〫 (just East of North) to 270 〫 (due West).

The event precipitating this crash was flying into an area with some combination of super-cooled precipitation (small water droplets can be well below 0 〫 C and not freeze) and ice crystals in sufficient volume to overwhelm the anti-icing capabilities of the pitot probes (which sense the pressure created by the aircraft's movement through the air). The pitot probes on AF 447 were fully functional, and complied with certification requirements.

An unusual number of airspeed loss incidents in the A3xx (320 / 330 /340) series due to water ingestion or icing during heavy precipitation, but within the allowed operating limits of the airplane, caused a 2001 Airworthiness Directive (AD) to replace the original Goodrich manufactured pitot probes with uprated Goodrich or Thales probes. The latter were installed on Air France A330s.

Further A3xx airspeed losses led to a 2007 Service Bulletin (SB) recommending replacing the Thales probes with a newer Thales design that was in response to A320 water ingestion at low altitudes. Unlike ADs, SBs are advisory.

Because Air France only had problems with its short range A320s, it elected to replace the original Thales probes on the A330 / 340 series only following service failure.

In 2008, A340s suffered 7 high altitude airspeed failures. Air France asked Airbus if the uprated Thales probes would remedy these failures.

Airbus replied that they were developed to deal with water ingestion; therefore, they had no increased ability to deal with icing. Further, Airbus also stated there was no way to completely eliminate icing risk, that all the installed probes exceeded certification requirements, and that there was a procedure for incorrect airspeed indications.

In early 2009, there were two more airspeed loss events, including the first on an A330. Air France then decided to replace all the probes on the A330 / 340 aircraft as soon as the uprated parts became available.

Reiterating "for want of a nail" horribly, the first batch arrived six days before the mishap.