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AF 447 Thread No. 7

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AF 447 Thread No. 7

Old 20th Nov 2011, 22:59
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Lyman pontificated:
There is a soft bottom line, of course. To me, continued questions and a resistance to knee jerk pronouncements, plus an unwillingness to eliminate even a remote possibility, is preferred.
That's because only a fool would eliminate possibilities until the final report is issued.

Hope this helps.

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Old 20th Nov 2011, 23:26
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While there is a lull in the current aerodynamic discussion, an Airbus initiative on future FDR options has been published in the August 2011 edition of FAST TECHNICAL MAGAZINE-#48. In light of the difficulty in locating AF447, the options they are exploring for pre-crash alerting, jettisoned ELT and floatable QAR devices are touched on. Well worth a look.

NOTE: File is a large PDF - 9MB
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Old 20th Nov 2011, 23:29
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There are those here who reject other than PE as the procuring cause of this fatal wreck.

I believe the Pilots may have inherited an UPSET airframe, and were unable to recover the flight path, for reasons as yet undetermined. A chorus of 'consensus' notwithstanding, the Procuring cause has gotten virtually no attention, every thing has been a buzz of holier than thou judgment. Pontificate? As in: "These imbeciles?"

At the end, it is likely no complete certainty will be reached. There will be questions left, it is common.

A finer point for you? I think you may have misinterpreted my post. I have no inviolate opinion.
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Old 21st Nov 2011, 00:45
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@Lyman,
Sorry, I think I may have read it backwards or upside-down.
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Old 21st Nov 2011, 11:04
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Originally Posted by infrequentflyer789
We mostly agree. I think the autotrim discussion probably merits a thread in itself as it goes much wide than this accident.
Why not

Originally Posted by infrequentflyer789
In more general terms I fear the industry may have got itself into a nasty spiral:
  1. more accidents per hour in manual flying therefore we should use more automatics
  2. only times pilots get handed the plane is when George says "something's wrong because we've got to the edge of the envelope, I have limited (no) intelligence and don't know what to do now, so you have control. By the way, that's the stick shaker..."
  3. resulting crash happens with human in control and is then another tick in the "mechanics are better than meat" box
  4. return to (1)
Nicely put!

Originally Posted by infrequentflyer789
I've thought for a while that it might even be beneficial if George took a mandatory random bathroom break every flight or so, just to ensure the real pilots are kept excrcised. Ecam: "you have control, I'm off down the back for a pee and to chat up the cute FA, back in 15".
Now that would be a reason to call automation "HAL". The under-tought is interesting but please don't try to sell it that way
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Old 21st Nov 2011, 13:57
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ATPL’s should comment rather than people like me, but I would have thought any manual practice in line flying is almost useless if just taking over from AP when in level cruise. I have noted several older pilots talking about taking every opportunity, SOPs etc. permitting, to do descents, climbs, and other things that are more active, to keep current; and deploring the modern tendency to keep hands off and let AP do it all.

In my line of (office) work, some of us used to query whether somebody claiming years of experience really only had about 1 year, repeated multiple times. I wonder about flying hours the same way (as somebody else here hinted at) – thousands of hours might be mostly thousands of times doing the same sort of hour, letting AP do it all, with actual decision making and manipulating controls being – what? A few hundred?

I would be interested in informed answers to that.

Chris N.
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Old 21st Nov 2011, 15:43
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ChrisN, this probably belongs in a thread of it's own, but hand flying a FBW "protected" Airbus in normal law, requires a different skill set than does hand flying a non "protected - normal law" aircraft. That in itself is not a bad thing. I have no problem switching between a simple Cherokee 180 and a FBW Airbus. The skill sets are different and it is quite simple to fly each with the appropriate skill set.

You wrote:
Originally Posted by ChrisN
ATPL’s should comment rather than people like me, but I would have thought any manual practice in line flying is almost useless if just taking over from AP when in level cruise. I have noted several older pilots talking about taking every opportunity, SOPs etc. permitting, to do descents, climbs, and other things that are more active, to keep current; and deploring the modern tendency to keep hands off and let AP do it all.

In my line of (office) work, some of us used to query whether somebody claiming years of experience really only had about 1 year, repeated multiple times. I wonder about flying hours the same way (as somebody else here hinted at) – thousands of hours might be mostly thousands of times doing the same sort of hour, letting AP do it all, with actual decision making and manipulating controls being – what? A few hundred?

I would be interested in informed answers to that.
I'm not certain what it is you are asking, but I'll attempt to answer the question I perceive you to ask.
The skill set required to hand fly a transport category swept wing turbojet at normal cruise altitudes with no abnormals and in fair meteorological conditions is FAR different than the skill set required to hand fly the same aircraft when said aircraft is turned over to the pilot in an abnormal situation in bad weather. (An additional bit of information you should know is that RVSM rules effectively outlaw hand flying at cruise.) Hand flying the above described aircraft at cruise in optimal conditions requires nothing more than a normal instrument scan and minor corrections. So yes, the skills required to hand fly in optimal conditions would not necessarily transfer to "recovering" the same aircraft when the A/P hands the pilots an unknown and abnormal situation. This is similar to the difference between a normal take off and one that includes a critical engine failure. If you take a proficient single engine pilot (centerline thrust) and put him/her in a light twin and include an engine failure on his first take off, with no previous demonstration or instruction in engine failure procedures, his performance is likely to be unsuccessful.

As mentioned, the skill set required to hand fly our aircraft in an abnormal would be FAR different than normal straight and level. The only solution would be to provide pilots with practice dealing with some of the potential abnormals.

The autopilot on my A320 disconnects at cruise with some regularity. Sometimes I do it myself when my Jeppesen manual bumps the disconnect button, sometimes it's the FO,..... Whatever the reason, the A/P disconnects, you take the controls and then re-select the A/P. Simple. I have never in my career, been handed an aircraft under the following conditions: at night, in turbulence, with questionable instrumentation, and in a questionable attitude. Neither can I think of any way in which to practice such a scenario.
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Old 21st Nov 2011, 15:55
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Earlier, Infrequentflyer789 mentioned it possibly being beneficial for the automation to "take a break" on occasion.

In my opinion, that would be of very little benefit, if any. As I wrote to ChrisN, the skills required to deal with an abnormal in cruise are far different than the skills required to take over from a lazy autopilot every once in a while. Allowing the automation to take a break would only provide practice in normals; what the AF447 pilots ( and most of the rest of us, including myself) really need is practice in ABnormals.
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Old 21st Nov 2011, 16:00
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Flying versus monitoring

Salute!

A very good question, Chris, and it gets to the heart of the matter WRT AF447.

Your observation hits home with this old military pilot who never flew a heavy. And I am sure that 'bird, Retired, Smilin', Wolf and others can chime in here.

Make no mistake, I used the AP a lot when not engaged in a serious mission requirement like air combat or dive bombing or flying formation or in-flight refueling or low level navigation at 200 feet or lower or.... I preached the value of even some crude AP's we had, like the one in the Viper. My other AP's in the Voodoo and SLUF were really good, especially the Voodoo. We could "couple" Otto to the ILS and simply observe and adjust the throttle until field visible. The F-106 could couple Otto to ground radar datalink and actually steer the interceptor to a position that enabled radar lock-on of the "enema" bomber.

The biggest use of Otto was in bad weather and having to plan an approach or calculate fuel required to an alternate or to simply get your act together. Then we had the long haul missions like flying across the ocean while sitting in a small chair with no snack bar or flight attendants, heh heh. Of course, we would have to snuggle up when weather was crappy, and then we had to get within 20 or 30 feet of a big guy to sip some gas.

Our good-natured jibes at the heavy pilots was that we had less hours but more landings. So in 4,000 hours I had maybe 3,000 landings. We also had 95% manual flying, often at the edge of the aero envelope.

So I feel we need to seriously look at the training regimen of the airline pilots. Get them into something capable of stalling and spinning and buffeting and....

Back in the 70's, USAF assigned T-37 trainers to the buff wings so the pilots could actually practice stalls and do some aerobatics. Was a well-accepted program, and was dirt cheap.

later,
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Old 21st Nov 2011, 16:51
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I was the painter of the stick movement between 2:10:07 and 2:10 18 at end of juli 2011

please, take a pin or a joystick in your hand and follow the movement, for every sec there is a number on the paint,

it is not so fast, the PF did not rest but he controled his moves, try it !
if you will make (shake?) mayonaise, like jcjeant called this picture, you have to move the stick 10 times faster


http://www.pprune.org/tech-log/44773...ml#post6610311

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Old 21st Nov 2011, 18:02
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TT, and Gums, thanks. TT identified the first part of what I was asking about – sorry if I did not express it clearly enough, but you got there.

(I know amateur gliding is miles removed from flying airliners, but in instructing, once past the essentials, most of the further training is in dealing with the unusual, not seeing once again that the student can fly the easy bits with no problems. I would have thought almost all subsequent checks and training follow that, for power including airliner flying, in sims or reality; and to the extent possible, also in self-imposed currency practice in manual flying. It seems obviously most beneficial if handling the more difficult bits. You confirmed it.)

The other part I was interested in was the “000’s of hours of experience” vs “1 hour 000’s of times over”. (An exaggeration, but I think you know what I mean. Like Gums’s many landings. And I have even more landings per hour than him!) I am not criticising the AF447 PF; rather, if anything, questioning the selection, training and check regime that led him to being at the controls in a situation unprepared for. But just how many hours of his few thousand would have been experiencing new stuff ?

Any guesstimates from those in a position to say?

Chris N.
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Old 21st Nov 2011, 18:12
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Grity, I’m glad you posted that again – don’t know how to find the first posting easily.

I tried what you said. I think it serves to confirm something Retired F4 sent to me in a pm (he said I could refer to it here if I wished). He came up with a rationale for what PF was doing, and why.

While I understand F4’s detailed analysis, the amplitude of the SS movements (at M. 0.80-0.82) seemed to some other commentators, and to PNF if I understand his remarks correctly, to be inappropriately large or rapid. Again, ATPL’s and AB drivers particularly would comment better than I could. I know that my much slower glider, like most or all gliders, has an envelope that prohibits full control deflection at VNE or speeds approaching it. I would have thought that some limitation would apply equally to airliners – unless “Hal” protects regardless of what the SS calls for. (Sorry, but I get too easily lost in what still works in alt1, alt 2 and direct. I understand when people spell it out, but can’t remember in between times.)

Chris N
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Old 21st Nov 2011, 18:25
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Nice Depiction of the stick movements Grity! Somehow I had missed this the first time.
Earlier I had noticed a ~2 second period between stick reversals in the BEA data. For a transport sized aircraft, this is very rapid. Mayonnaise stirring for sure when you consider the scale of what is happening with the aircraft. And look at the amplitudes of lateral stick travel!.
PF had to be all tensed up with his mitt firmly around the stick. Probably with his arm not properly supported as well. Hard to keep from pulling a stick back inadvertently under those conditions. (But keep in mind I've never sat in an Airbus Cockpit).

Last edited by Machinbird; 22nd Nov 2011 at 00:49. Reason: SPELLING can be important
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Old 21st Nov 2011, 18:44
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Originally Posted by Machinbird
PF had to be all tensed up with his mitt firmly around the stick. Probably with his arm not properly supported as well. Hard to keep from pulling a stick back inadvertently under those conditions. (But keep in mind I've never sat in an Airbus Cockpit).
I don't think even with a death-grip on the stick it would be possible to inadvertently pull halfway back without intending to - there's a fair amount of travel involved. But the kicker is that he *slammed it back against the stop* from 2:11:40 to 2:12:15, and there is absolutely no way that could be done accidentally.

One of the things that has occurred to me recently is that with the arrival of big and powerful high-bypass engines 35 years ago, much was made of the "rocketship approach" to things like windshear - which over the years may have been corrupted into a belief that modern engines are powerful enough to get you out of almost anything. This fits with the PF's comments about being in TOGA, in that he may have believed that with the donks at full chat stall was an impossibility. I don't know what kind of groundschool knowledge was imparted to AF cadets, but if the fact that the higher you get, the less effective the engines are was not drilled in then it could have contributed to that kind of misconception. Obviously you have SOPs for things like engine-out in cruise in which descent to a lower flight level is necessary, but were the cadets ever taught why?
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Old 21st Nov 2011, 19:12
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Originally Posted by ChrisN
(I know amateur gliding is miles removed from flying airliners, but in instructing, once past the essentials, most of the further training is in dealing with the unusual, not seeing once again that the student can fly the easy bits with no problems. I would have thought almost all subsequent checks and training follow that, for power including airliner flying, in sims or reality; and to the extent possible, also in self-imposed currency practice in manual flying. It seems obviously most beneficial if handling the more difficult bits. You confirmed it.)
You would think, wouldn't you? Sadly, in the US this is not exactly the case. The FAA requires recurrent checking. Not specifically recurrent training. My carrier, as do most others, are loath to provide more than the FAR's require because training is expensive. I take a PC (proficiency check) once a year and a PT (training) once a year, spaced six months apart. Sometimes I take two PC's a year due to pairing limitations in the training schedule.(my training partner may require a PC, a situation that makes us both fly a PC).

A PC is effectively an instrument checkride. In the Airbus, due to it being "stall proof", stalls are not checked. The PC consists of instrument departures, instrument approaches, engine failures on take off, and one or two minor abnormals (such as an airpac failure that leads to an emergency descent), one of the emergencies is usually a engine failure that leads to a fire that leads to an evacuation after landing. This sequence has not changed for me in over twenty years. Effectively, I re-take my ATP checkride over and over again. It's like the Bill Murray movie, Groundhog Day.

The PT I am scheduled for once a year usually consists of PC practice (engine failures at V1, for example) and instruction on a particular procedure (such as a specific arrival/approach/missed approach into a particularly dangerous airport. Guatemala City or Bogata, Columbia for example)

In summary, there is very little time to train things like high altitude stall recovery, and since it is not required, the airlines don't desire to spend the time(money) to do so. To my carriers credit, they did include the UAS/ADIRS failure procedure in our PT's last year. But we trained it once and I don't expect to see it again in the near future. This last PT, I spend a great deal of time taxi-ing around in significantly reduced visibility which is actually good training because runway incursions have killed more pax than Airbus UAS events.

The only answer I see to the problem would be regulatory. The international aviation industry regulators must demand that the carriers provide realistic training in a wider range of abnormal system and aeronautical events instead of focusing on things that were pertinent in 1966.
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Old 21st Nov 2011, 20:02
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Cool

Hi,

DW
I don't know what kind of groundschool knowledge was imparted to AF cadets, but if the fact that the higher you get, the less effective the engines are was not drilled in then it could have contributed to that kind of misconception. Obviously you have SOPs for things like engine-out in cruise in which descent to a lower flight level is necessary, but were the cadets ever taught why?
but were the cadets ever taught why?
Well if it's not taught in a flying school (different power effect with altitude) .. this will demonstrate that the schooling level in Françe is very low
It's just a physic principle you (normaly) learn in teenagers school level
I wonder if .. at end .. the famous "concierge" will be better choice for Air France than those cadets ...
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Old 21st Nov 2011, 22:22
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Salute!

You scaring the hell outta me, Tex.

How much of your checkride was engaging and disconnecting Otto?

Upsets?

Mach buffet versus basic turbulence versus approach to a stall?

The basic Airbus design seems robust, and we have all seen great examples of the airframe and pilot skill such as Sully demonstrated.

My point is that I am not worried about basic profiles and even emergencies such as loss of an engine or such. I am more worried about lack of basic airmanship when Otto quits and the crew has to coordinate, communicate and such.

I sure hope that all the airline pilots look at the AF447 example and demand better training for those 1 in 10,000 times when something goes wrong.
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Old 21st Nov 2011, 22:56
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Originally Posted by Dozy
I don't think even with a death-grip on the stick it would be possible to inadvertently pull halfway back without intending to - there's a fair amount of travel involved. But the kicker is that he *slammed it back against the stop* from 2:11:40 to 2:12:15, and there is absolutely no way that could be done accidentally.
Dozy, In my opinion the reason for the stick against the stop after the stall had nothing to do with the earlier nose up inputs seen in Grity's graph. The post stall nose up was an effort to control the nose bobble in the stall. You can see clearly when PF changes his strategy in the BEA stick position charts.

The early nose up inputs have to be the result of an improper (palmed) stick grip. Do you see the NE-SW orientation of many of the motions? These indicate (at least to me) that PF was controlling the aircraft in roll with wrist flexion instead of rotation.
When he had to get to the far left corner on the chart, he was probably pulling his elbow off the rest also. Looks like the "Death Grip" on the stick was going full blast from the beginning. He wasn't at all relaxed.

Maybe they should put force transducers inside the stick to measure the "squeeze" on the stick. That might tell the psychologists a lot about a pilot's mental state.
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Old 22nd Nov 2011, 00:24
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Gums, I'm not in the training department, therefore I don't keep up with the specific FAR's. So this is from memory.

A standard FAR 121 Captains PC consists of: Low vis taxi, normal takeoff and area departure, airwork (stalls, steep turns, etc - the stalls are not required in the Airbus), one arrival, one normal precision approach, one single engine precision approach, one non precision approach, one missed approach, one CAT II/III approach (if CAT II/III approved) one V1 cut, and one emergency. The only times the A/P is required to be off are: one single engine ILS, and by at least MDA -50ft on the non-precision approaches. I'm probably missing something here, but for now I think you get the picture.

The only time we get training is in initial. After that, due to constraints of money, they give us the minimum, which consists of checking only. Occasionally we focus on something like the UAS/ADIRS, but that is the exception not the rule. I'm sure a training dept member will be able to give more data, but rest assured that we are given the little more than FAR mins. The same goes for recurrent ground school. It's now down to three days. One day on systems, one for GOM/FAR issues, and one for hazmat/security/etc. My current airline is my fourth and I must say that only one of the four actually provided me with thorough training in the airplane and on the ground. Interestingly enough, that carrier trained in the airplane (B1900) instead of using simulators.

It is my opinion that the US Airline companies rely more on the accumulated skill and experience of the Captains corps than they do on providing good training. IOW, they assume the Captains will give the FO's "on the job training" and that practice will continue from one generation to the next. This was likely good practice when the Captains were mostly military trained, but in the last 20 years the amount of ex mil pilots has dwindled. For the record, I am not military, but am well enough educated to recognize that the military produces/produced well trained pilots. I personally benefited greatly from flying with retired USN pilots early in my career. Unfortunately, historical accident statistics don't prove the past to be any better than the present. But I believe that to be an anomaly. Technology has improved safety, and has tempted airline management to hire less qualified pilots. When you mix a well qualified, well trained, well educated, well experienced pilot with technology in an abnormal situation you get the Miracle on the Hudson. Sadly, that generation of pilots is rapidly retiring.

Edit: One more thing, I am truly saddened and amazed by the number of pilots who chalk the AF447 accident up to nothing more than pilot error. I don't want to be seen as breaking my own elbow patting myself on the back, but I talk about this to everyone I can get to listen and most of them really can't conceive of it being anything other than a screwed up pilot. I personally believe the cause is much deeper than the pilot not knowing how to get out of a stall.
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Old 22nd Nov 2011, 00:25
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Originally Posted by Machinbird
In my opinion the reason for the stick against the stop after the stall had nothing to do with the earlier nose up inputs seen in Grity's graph. The post stall nose up was an effort to control the nose bobble in the stall. You can see clearly when PF changes his strategy in the BEA stick position charts.
Agreed completely, Machinbird. Like you, I see evidence (in both the control handling and CVR transcript) that the PF seems to have changed his mental picture (perhaps because he never found one that fitted with the plane's behaviour?).

IMHO the clearest example of incompatible actions for a single mental picture, are him mentioning TOGA (perhaps stall avoidance was in his mind then?), and at another time the "crazy speed" comment and (brief) deployment of the speedbrakes.

Therefore I believe comparing his actions at different times, to try to produce a consistent theory (or to try to disprove an explanation for one handling or another) is unfortunately futile, as his mental picture of the situation (and hence the reason for comments & control movements at each point) was likely varying throughout the event.
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