mm43

Do you know if they have continued recovering debris/bodies at the crash site? I am just curious to know, or whether they have given up.

tks.

OK465 (post 2292) -

"BOAC, you are correct, "most" is a relative term. The NG's I've dealt with have had AOA since 2001. I'm only familiar with specific carriers and all (not most) of their NG's have it."


I've been told by someone involved with the AOA program years ago that only AA and DL have ordered that option in the U.S. What carriers have you seen have the AOA gauge on the PFD and/or HUD?

promani
I have no information, other than the "Ile de Sein" has returned to the ROP following a crew change in Dakar.

My understanding is that the BEA may still be searching for the missing SSFDR ULB, and there could be other items they wish to recover. The BEA has made it clear that the recovery of bodies is not their mission, and IIRC the French courts have stopped any further recovery of bodies. DNA has been successfully extracted from those brought to the surface, and what may happen next is unclear.

The BEA may have something to say on this matter at their next press release.

Hi,

:confused:

Google Vertaling

Original:
Rio-Paris*: pas de remontée des corps trop abîmés - lesoir.be

I wonder how many (they are unknow of course :) ) people already survived to prove that ........

Reliability: a measure of the success with which a system conforms to some authoritative specification of its behaviour.

Safety: Freedom from those conditions that can cause death, injury, occupational illness, damage to (or loss of) equipment (or property), or environmental harm. Given that interpretation, it is then fair to say that there is no safe airplane.

When the behaviour of a system deviates from that which is specified for it, this is called a failure. Failures result from unexpected problems internal to the system that eventually manifest themselves in the system's external behaviour. These problems are called errors and their mechanical or algorithmic cause are termed faults. Systems are composed of components which are themselves systems: hence;
> failure -> fault -> error -> failure -> fault

Software doesn’t deteriorate with age: it is either correct or incorrect but faults can remain dormant for long periods. Ada is very much alive and well. I find it considerably amusing to read posts where the author assumes Ada to be a stale dinosaur - they seem to be quite far removed from reality. We use Ada for commercial projects achieving superior results in comparison with other languages - fewer bugs reach binary, easier to maintain code, certified and tested compilers, self documenting, and standards that read with legal precision... to name a few benefits.

I don't have a problem with the software engineering practices used in avionics. But I am weary of impacts on safety caused by time-cost demands.

There is a list of mechanisms that could make aircraft 'safer' but they aren't implimented because of cost savings. :sad:

http://www.computersociety.it/wp-con...c653_final.pdf

Does anyone know if an approach to stall was ever demonstrated in any FBW version of the Airbus while in Alternate law and with invalid ADR input to the the computers? (Please read this question in an AF447 context)

Judging from the X-31 example, one might want to be seated in an ejection seat while demonstrating that point. :E

If Friday's presentation does include a pitch up into a stall (as has been leaked), did it occur at a speed higher than actual Vstall for the configuration?? If so, AB will have some issues to deal with as well as AF.

misd-agin: (& BOAC)

Waving the white flag here.

You are correct. Only “some” 737 NG’s have dedicated AOA displays. I am sincerely trying to avoid A versus B and just present facts.

However, any 737 NG with a HUD has, for all practical purposes, inertial AOA displayed.

FPV’s displayed on the PFD also provide some semblance of AOA. However, the A330 FPV in the FPA/TRK mode possibly disappears below the lower white line on the PFD attitude display at high AOA, possibly without any feedback to the pilot as to un-displayed FPA.

NG HUD FPV “ghosts” when non-conformal at high AOA, and NG’s equipped with the analog/digital AOA display have just that much more information available to recognize very high AOA conditions and correlate that info with other displays.

True, it is a customer option.

How often have I heard, over the course of my so-called "career" as a "professional", this tired refrain?

There are bodies on the sea floor as we speak, that were put there by over-reliance on automation and plain, irreducible cheapness - the corporate mentality, the idea that ideas themselves are real, and that humans need to be removed from the loop. Fault tolerance - my a__.

228 humans have been permanently removed from the loop.

OK465, inertial AOA, speed. and all that is fine in more or less still air or air that is moving horizontally - as happens "99.44%" of the time. When there is an updraft the real AOA may be somewhat different from what is indicated. And when we're speaking of single digit degrees that difference could be significant. It'd be nice to invent a real "relative to the air mass" speed and AOA measurement system. Speed's been done. AOA is an interesting problem.

This has nothing whatsoever to do with maintaining a stable flight configuration while cruising at Mach 0.8.

deSitter, they might be considered to have killed themselves because of overreliance on air transportation. (If you can be crass I can trump you. If you think the programmers, designers, and everybody else involved with getting that plane into the air is not unset and feeling terrible about this accident you do not understand people very well. Programmers are people, too. And there are times we flat out TELL management there's no way in hell we're going to do what they want simply because it might have a significant probability of killing somebody when it shouldn't. Er we did some GBU-xx work in our facility. I was briefly involved in some of it. I could not handle the images that conjured. It was too close to real killing rather than communicating. I can argue that my work saved soldier's lives while they dealt with people killing me. Making the electronics in a guided bomb was just too much. We feel, too. And THAT is one of the reasons I support the military demands for Ada based software.)

So let's get real, OK. I used to be a company troubleshooter who got shoveled into situations where we had problems. I watched a high percentage of the programs that went through our facility. I was singularly impressed that I was never needed, never called in, for the Ada programs. Everything else, PL1, FORTRAN, C, Assembler*, and others needed me.

* several CPUs, usually to add features to something old.

Ada is more reliable. But, there is absolutely no way to make any human activity, even sitting on the potty and defecating, 100% safe under all conditions.

Is that what you think my point is? I don't care what your choice of weapon is, the issue here is computerization for its own sake, of automation in the name of replacing the human spirit - the one that used to carry flight bags full of approach plates and flashlights and candy bars. My bus - Landbus (TM) driver has more authority over his craft than the person who flies me to Tahiti. This isn't about this tool or that, it's about the obsession with automation for its own sake, how it has become an end in itself. The old hands know what I mean. My motorcycle and I have an understanding.

I should also add, that one does not see a similar obsession with automation where it might matter, that is, on runways and taxiways crowded with Cheapbus RJs stewarded (can I say that word now?) by overworked ATC personnel. Why? Because there is no profit in it.

I don't know about automation for its own sake, but I was amazed when I learned that the airlines were using autothrottles (in whichever form you wish to call it) to manage power during cruise, which ought to be the least demanding area of flight. Do you really want to give a crew so little to do that they have resort to reading books to stay awake? Whatever happened to setting XX pounds/hour per engine fuel flow or YY EPR and then backing it off as required to hold your cruise mach. Do you really save that much fuel?

When you leave the crew so far out of the loop in the actual flying of the aircraft, can you really blame them if they have trouble coming up to speed in an emergency?

OK, yes, I'm a dinosaur. I sometimes used autothrottles (technically an approach power compensator) to manage engine power while flying my swept wing bird aboard ship at night when you can use all the help you can get. But using it in cruise??:yuk:

What? You need help in a night carrier landing? What sort of pilot are you? :) Just call the ball or shut up and..

Testability
 

Machinbird @ #2321

:mad:To avoid the costs of ejection seats (or capsule) and destructive testing of the a/c why not to test in the same flights an augmented "APU" turbine? With a 45° rotating nozzle if necessary?:mad:

Back to uncensored mode:

Question:

A minimum of how many kN, for this class of a/c, would be required to play a "recovery from stall"? And for generic "unusual attitudes"? (using a 45° nozzle)

deSitter; Very simply, were there no accidents before computers were introduced into aviation?

The impeccable reliability of safety-critical computing has most likely lulled people into a false sense of security. Many accidents just wouldn't happen if there were a sober acknowledgment and balanced processing of the general risks associated with flight.

Mankind continues to push the flight envelope further, soon we will be routinely flying manned sub-orbital craft around the planet, which in itself is hardly a bad thing. Computers have enabled progess. But are passengers really aware (at a concious level) that they are paying to travel at near 800km/hr at -50C temperatures, through potentially hazardous weather, and in the dark?

AF could have eliminated the hazardous weather, and darkness risk factors, sacrificing schedules and incurring the cost of an AOG. A few days late, but so what? Passengers would still be alive?! Is it mankind's impatience, his disregard for the fury of the environment, is this our real culprit?

deSitter
 

More automation = more dangerous, is that your point?

Take a look at page 21 of this Boeing document, then please shut up.

http://www.boeing.com/news/techissues/pdf/statsum.pdf

Egads, I stand convicted. Let's get rid of pilots altogether, those accidents-waiting-to-happen! Vive le telechargement!

There are two problems with unreliable airspeed:
1. The unreliable airpeed per se.
2. The bigger problem is when the system (and the pilot) does not recognise that the airspeed is unreliable - and automation then insidiously takes the aircraft closer to the edge of the flight envelope.

Although the system obviously works most of the time, there is a weakness if the system uses 3 identical tubes to detect a problem. If the problem effects all 3 equally, then it can be missed. It will be unreliable, but not recognised as unreliable. Just as three 2nd graders can't together do 6th grade math, 3 problem tubes can't reliably determine airspeed (nor even the state of unreliable airspeed).

With pitot tubes, you are using air flow through the tube to create a pressure, which you then compensate for altitude by using static sensors, and then converting this compensated pressure back into flow (or airspeed). There are a lot of links in this chain. Even worse, a problem could generate either an over-speed (eg blocked pitot drain hole) or an under-speed (blocked tube).

When it is difficult to measure something important, an alternative that is easy to measure becomes important. And so it was 200-300 years ago - flow was difficult to measure, pressure was easy, and so we calculated flow from pressure.

Maybe the time has come for us to measure flow, and thus airspeed directly. Presumably that is the principle behind the laser systems currently being developed.

It may be that pitot tubes today are dinosaurs looking for a tar pit.

The concept of having safety enabling features as "customer option" is somewhat scary. Assume an accident happen and the accident investigation finds out that "lack of AOA information to pilots contributed significantly to the cause". Should the blame fall into the airline beancounters who saved by skipping an "unnecessary option". Or the airplane maker, whose business model includes making extra profit with optional features?

To get back to AF447, the Air France beancounters were reluctant to upgrade pitot tubes to safer ones. I have no idea what the price of the pitot upgrade was, but probably it was not cheap, since it got beancounters on their toes. Blame beancounters? Well, the other side of the coin is that Airbus/Thales was making a profit on what was essentially a safety fix...

This is an attempt to redirect the recent negative tone of this thread. :eek:

This statement is a very good one. Yes, automation has advanced aviation safety...on the flip side it also has created a false sense of security.

That is why this is a watershed event. It seems that AF447, with what we think we know at this point, is the "perfect storm" of the "human vs. automation" argument. So the point of conversation should not be whether you would rather have HAL flying you around, or a Sky God from the past flying by the seat of his pants! The point should be how do we move beyond this discomfort and meld man and machine. My guess is it may take more man power than originally assumed...which my cause some impediments on advancement.

'keitei' makes an interesting point in #2335 .

May we put this 'AoA/FPV' etc discussion to bed here please? You can have a 'safe' AoA with a dangerous FPV and vice versa. AoA, as those who have used it know, is a great tool for approach and landing. Trying to 'peg' a value of 'AoA' or an 'FPV' in the middle of a storm area would, I suggest, defeat most 'sky gods'. The more info you put on a display, the more 'chimes/alerts/ECAM messages you insert, the more challenging it is to sort wheat from chaff when it all turns to crock - sensory overload cuts in big time, and I'm sure happened here, and the captain (reportedly) shouting commands at the pilots could have added to the distraction (Q - what is the first 'sense' to be lost under stress?).

The message is clear, if 'old-fashioned' and not 'software driven'. Maintaining the correct pitch and power will generally get you out of trouble, despite temporary 'excursions', even momentary stalls/high-speed excursions, if the weather is really rough. Overall you should get through it. Rely on what may be badly degraded bells and whistles or excessive clever and pretty CRT displayed info and you may well not.

29 Bodies recovered
 

Source Vesseltracker
"Since May 21, another 29 bodies have been recovered from the wreck of the crashed Air France flight from the bottom of the Atlantic by the "Ile de Sein". The ship had returned to the crash site off the Brazilian coast on May 21 coming from Senegal with a replacement crew. Meanwhile a total of 82 human remains have been recovered of the 216 passengers and 12 crew members on board the AF 447 flight."

I think that the authorities are now focusing on bodies recovering rather than the wreckages by themselves.
I'm still wondering if the cockpit has been recovered and bring to the surface.
During the last BEA press conference, Mr Bouillard briefly spoke of the cockpit recovering and it was not clear, even for him, whether it had be lifted to the surface or would be "soon". I have not recorded the footage and I don't recall exactly what he said precisely.

...and the embarrassment continues!

Pitot tube measure airspeed via dynamic pressure, this is also what the wings use to generate lift. Measuring air molecule approach speed (laser?) will still need air density from static pressure and temperature from temperature probe. Pitot tubes are simple and have well known failure modes - how long will it take to develop alternatives to the same level of maturity?

What is not clear is why these simple devices seem to have increased number of incidents in cruise - in conditions that are uncertain and do not form part of any current certification requirements. Is it subtle changes to planned flightpaths or "Climate Change". I have no doubt if a reliable test of the "alleged supercooled liquid" or my preferred explanation of "particle size distribution of micro-fine ice crystals" can be generated - pitot tube heating can be redesigned to prevent blockage - but don't hold your breath waiting to get them introduced any time soon.

The now preferred Goodrich probe has also already suffered icing, but my understanding is that it is less likely for the drain hole to block, so blockage of the ram port should give a more obviously failed low reading, for example:-

Investigation: AO-2009-065 - Unreliable airspeed indication - 710 km south of Guam, 28 October 2009, VH-EBA, Airbus A330 202

To be fair there was (and still is) a technical debate as to whether the alternate probes are significantly better for high altitude icing. The change was not a mandatory safety requirement, there was just a logistical supply issue and biggest cost would have been taking planes out of revenue generating service for unscheduled service.

Some great reading and food for thought here. I especially find myself siding with desitter. Aside from the pros and cons of automation I think that EU OPS (JAR OPS) and regulators as a whole have a part to play in the short comings of this accident. Whilst EU OPS has improved the training depts output in low end airlines, their rule-making may have had the opposite effect on the bean-counter led airlines training depts. The bean counters are constantly putting pressure on training dept heads to cut costs and slim down. The, 'we train to proficiency' (no more no less) mentality is now showing the fruits of it's labour. Personally I don't remember any really challenging training scenarios for many years now, actually since 1997. The usual LPC items have been covered and the training day is the usual rushed affair with trainers who have less and less to give, or are allowed to give. Very prescriptive, sterile packages. Very few 'old boys' that put you through the ring with scenarios that are multi dimensional. God forbid that we give our pilots multiple failures, they might fail! That would cost money and that's not an option.
It's time to train hard again, it's time the regulators got real with training, it's time that pilots with 'heavy training files' were given the extra mile, and it's time that PC took a backseat and allowed the truth to be told. A few egos may be bruised but a few lives may be saved.

Razoray said "So the point of conversation should not be whether you would rather have HAL flying you around, or a Sky God from the past flying by the seat of his pants!"

That's right, and it's not. It's about over-reliance on automation in all aspects of our modern existence, not just in the air. I can't begin to tell you the damage this has done to my own specialty, physics, where people are starting to take models as reality, and to actually believe that the model is giving them direct information about the world. This has gone so far as to cause people to imagine that they've got reality licked down to the first nanoseconds of existence, and that up to 95 percent of the universe is unobservable, and all this within 100 years of discovering its most basic rules. In this toxic and neurotic environment, it's almost impossible to have a reasoned discussion - the digital universe has acquired a life of its own, and a strange religious fervor has settled over what should be the most rational and sane of investigative bodies. One fantastic whopper after another emerges from the dark vortex of neurosis that has ingested academic physics.

There is no earthly reason to have an airplane whose crew are mere stewards to some cheap pile of circuits somewhere in its chin. There is nothing wrong with using computers to help control an airplane, but from reading all this catechism of modes and laws of the FMC, I'm strongly reminded of the irreal universe of modern physics. The same deadly neurosis is sweeping over aviation under the pretense of cost savings. There is something utterly disturbing about the idea of a perfectly good, flyable airplane falling from the sky because its crew are sitting there staring at screens and processing idiotically coded error reports generated by some pimply digeratus with a belly full of fast food and soda in some tacky office who knows where? I've seen IT/software engineering/whatever buzzword you wish to use from the inside and it's ugly, and whether it's a pile of milspec engineers or a crowd of H1B slaves makes no difference.

Jebus - that's some serious bile you have there. Ever tried counselling?

Then as a physicist - a man of science and reason - you of all people should be aware of the dangers of confusing a single anecdote with data.

de sitter. :eek: That is probably the truest statement in ........... the history of the universe. :D

squawk ident, thank you for the update.

That would seem to be a very fast recovery rate, given the time it takes to get to the bottom and then back up.

It may be that the Ile de Sein's crew change was to bring aboard more members of the National Gendarmerie.

http://www.diplomatie.gouv.fr/fr/IMG...fo_anglais.pdf

* National Gendarmerie’s Criminal Research Institute (IRCGN)

Speculation, but this recovery phase may be concentrating only on recovery of the bodies, and once that is completed, the Ile de Sein would again swap crews if any other parts of the plane are to be retrieved in the future.

DozyWan, anyone who appreciates the ugly reality of pseudo-engineering cannot help but be galled.

Trust me, if you'd actually studied Software Engineering at even an undergraduate level, you'd quickly realise it's a discipline that shares the same reliance on repetition, models and a*se-achingly dry textbooks filled with complex graphs and barely-comprehensible formulae as engineering of any other stripe. Are you stating that as far as you're concerned the only "real" engineering exists in the physical realm?

Some Computer Science degrees these days tends to effectively be BSc Java Programming, however a Software Engineering degree is a very different beast that happens to share the same underpinnings.

Mr. Pitot's tube(s)
 

One or more Pitot tubes have been fitted to most aircraft that have ever flownn and a better system of finding one's airspeed has yet to become general aviation practice - or even perhaps, invented.
This, basically, for those who find to their horror, that all aircraft, ancient of modern, have a "single point of failure".
Mr. Pitot's invention has served aviation well, worldwide, and throughout the ages, so calm down people ... !!

Strawman, and a misreading of deSitter's theme. His point is behavioral and systemic, which is over-reliance on automation, which leads to an imbalance in the man-machine interface.
Take a look at page 21 of this Boeing document, then please shut up.

One would expect that, over the time frame given, and the amount of time and effort expended, that causal factors would be identified and solutions proposed. The accident rate would be expected to go down, due to a cultural imperative that it do so. It has been reduced thanks to the flying community communicating to, educating, and training pilots, crews, and all ground staff on accident prevention. Likewise the technical fixes/advancements that have come along. (IFF? TCAS? ILS? GPS? Wind Shear detection?)


That said, each tool has its limits, and traps.


What has also happened in the last sixty years, oldchina, is that we now fly successfully in conditions that we could not at the start point of that graph. So we do. In the year 2011, passenger aircraft are able to risk departing from and landing in more dangerous conditions than when I was born. You could say we are collectively trying to get to the very edge of the danger zone on a routine basis. So the risk profile (and the need for greater mitigation) is much higher now.


The man-machine interface is at the heart of modern machine accidents.

The most effective mitigation for that is training and profieincy in use, as well as awareness of the machine's limitations. As true of my car, or lawn mower, as of any aircraft I ever flew.

I don't think those numbers tell you what you were asserting in your demand that deSitter shut up.

Jig Peter's right. The Space Shuttle has ................... pitot tubes.

NASA Media Item

Agreed, Jig Peter. There are thousands of planes relying on pitot at this instant. Icing seems to be a rare event, and even more rare in non-Airbus.

Thanks to Sensor Validation for the OZ link, from which I quote.
Are they building the best pitot they can, or just building to (inadequate) requirements?

I'd suggest there is a high probability that the reason that is so, is because "general aviation practice" has commonly been to follow the axiom: If it ain't broke, don't fix it.

As these UAS incidents have been on the increase, and probably already "contributed"* to major loss of life, perhaps it's time to consider Mr. Pitot's tubes "broke"? There are plenty of other ways to measure airspeed... Surely one less disturbed by ice crystals could be adopted for back-up at altitudes where they're encountered?

* Though the statement UAS "is not cause for Loss of Control" is undoubtedly correct, I think it is likely to be a significant link in a chain of causal events.

Very true. But maybe their time is drawing to a close Its not that the pitot tube has suddenly become inadequate. The issue is that the rest of the system has moved on over 200 years - to the point that the system the pitot inputs to now may not adequately cope with the occasional pitot malfunction.GIGO.

Pitot tubes must have been suffering from occasional episodes of icing for many years. The problem is not so much that the tube generates a false airspeed. The problem is that the technology may not be able to reliably pick an UAS state, makes changes assuming the false airspeed to be true, and the pilot is increasingly out of the loop with degraded SA.

I would like to see more emphasis on pilot training and simulation as suggested by others. I really would. Not to turn back the clock and throw out the automation. But to help improve the pilot:system interface, which is something I suspect has been neglected somewhat. For many reasons, I am doubtful that is going to happen however - a new generation less critical of technology, economics, start-up airlines in developing countries (with some very poor track records), existing airlines facing increased competition, reducing hours requirements.......

Its not just aviation. Its every aspect of our lives. Less understanding, but more acceptance of technology (? blind faith) despite this decreased understanding.

Would it help if the heating elements were beefed up? Too low tech?

On an emergent path to DIRECT LAW, the automatics degrade, losing protections. From 'Monitor' to PIC, the pilot gains SA and acquires command as the Computed Flight Path disappears. I submit that in any "Loss" of acuity, whether Man or Machine, one be selected immediately to Fly the airplane.

BOAC wrote some scholarly papers on this. Can we see the links?