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  • #31
    Originally posted by Evan View Post
    Such as...
    Such as if you don't remember the memory items, were not trained for high-altitude UAS, are startled, or a a betting man that like cowboy improvisation and willing to not go around when you just lost visual contact with the runway after passing minimums and receiving 13 GPWS alerts.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

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    • #32
      Originally posted by Jhonmicky View Post
      Hello everyone,,
      Involved in a discussion of the computerization of recently produced automobiles, trying to make an analogy to fly by wire. Attempting to reference pitot tube failure. Got hung up on how fly by wire systems compensate for loss of pitot tube sensing. I know that not all systems are dependent on working pitot tubes. But all I remember of the long detailed discussions of crashes involving pitot tubes is something about power and attitude. So maybe someone can remind me of where the pilots turn when they no longer have air speed data. It is my impression that air speed is very critical to flight management, but pilots can still aviate after the air speed is unreliable.
      First of all, let me welcome you to jetphotos. In my eyes it's still somehow incredible. I'm here since, ok half an eternity. There are other seniors who are here since a full eternity.

      So, you are completely new here on this platform. Ok, if you like to say that. But never on Earth you are new to aviation. Nevertheless, I was 30 (thirty) years old when I wrote my first jetphotos forum entry. So, I was a jetphotos junior at the age of 30!

      Back on topic. You are not new to aviation, imho. So, what are we talking about? Come on. France is such a great country, and that's the opinion of a man who certainly knows more Italian melodies... The A320 was invented in France, you mentioned fly by wire. That's not new. LH ordered A320s beginning with the year 1985.
      Two quite serious aviation accidents happened on board of an A320 or A330, in combination with 'pitot tube failure' and/or the really not new fly by wire in an A320.

      1. 1988, June 26th. Which must have been an inauguration flight for the A320 in France. But somebody chose the completely wrong Flight Captain for such a procedure. 44 years old by then, so, born 1944, he must have thought that he is something like a God. Although in 1988 there definitely had been jet pilots who fly the A320 much more careful than this daredevil. Not necessarily the LH CEO, but Spohr spontaneously comes to my mind.
      Now, I am 41 years old. So, old enough to be a thoughtless daredevil? People who are with me in a car when I drive do not confirm that. A pilot (passage airline) has to be aware that he does not fly dead pigs. But 130 passengers, back then, 1988, at Habsheim. You can be 44 years old with xx,xxx flight hours on whatever a/c types on this planet, I only count the flight hours on type A320,
      especially for a so called flight captain who is
      a) on a completely new a/c type and
      b) on a tiny airport where neither he nor his F/O has ever been before and
      c) who does not obey the 11th commandment in aviation,

      You shouldst never fly a passenger jet in low-level flight.

      Definition: not below 1970 ft AGL !

      If I know this 11th commandment, then he also knew it, I'm sure. And he ignored it, without the exact knowledge of the 'alpha protection' rule, which is a killer combination together with low-level flight in unknown terrain.

      Who am I to teach a man who was born 1944 how to fly a jet full with passengers?! There is a difference between Cargo and Passage. Passengers do write down what they experienced after the flight, in contrast to dead pigs.

      The second case, AF 447, is the best example for 'how to NOT react to a temporarily pitot tube failure'. Again, passengers died. But not due an egomaniacal Flight Captain. During AF 447 the Captain, Monsieur M.D., obviously was the only one who could have rescued that flight.
      No pilot names. But that Captain deserves my respect. Within seconds he saw what went wrong, with his 6300 flight hours as a Flight Captain (responsible Flight Commander).

      I have heard of flights with more than 1 pilot in the rank of a Captain (four stripes), so, rather 2 Captains and 1 'apprentice' (F/O). So that always 1 instructor is present in the cockpit, to avoid the 'sleep gap', to avoid misunderstandings, especially on the long haul. That's not cheap. But in case of AF 447 it obviously had saved 228 souls..

      Two newbies in an A330-200, and the Captain needed his sleep, so left the cockpit. That's the first thing which I've learned when I was a young aviation enthusiast, 30 years ago. You pull the yoke, that's one of the best ways to slow the bird down. In a Cessna 172, in a Fairchild Swearingen Metro, in a LH-B744, and also
      in an Airbus A330-200.

      So, what should you do in case of pitot tube failure. Please do me a favor and do not pull the yoke. You can try to descent or accelerate. But the best way of reaction is, and this is also what the BEA (Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile) published back then,
      do nothing.

      And I have to second that. All jets which I know since I am here on this platform have one very cute quality. A320, A330, A340, A380, B763ER, B777, B757, B747, all of them try to gain speed after a descent which was (apparently) begun with a loss of speed.

      That means, all these jets are able to regain a stable flight situation , if not,
      yes, if not a F/O who knows nothing
      tries to pull the yoke out of that jet.

      Please don't pull the yoke if you try to avoid a stall.

      Leave the elevator alone, and your aircraft will recover! That's what the experienced AF 447 Flight Captain tried to say, but the newbies called him too late..
      Last edited by LH-B744; 2019-07-30, 06:30. Reason: Sometimes we should ask the instructor again, the AF 447 PNF, the captain.
      LH and the Hamburg - Düsseldorf - Shannon - NYC route, open since June 1st, 1955. A/C type: Lockheed Super Constellation.
      EW, one of the dearest LH daughters, the brandnew November 19 schedule (frequency):
      DUS - VRA (--3-5-7), DUS - EWR (1234567), DUS - MIA (1-3-56-), DUS - BGI # 1152 (Mon and Thu with exceptions), ...

      Aviation enthusiast since more than 30 years. A whole decade here on this platform.

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      • #33
        Originally posted by Jhonmicky View Post
        So maybe someone can remind me of where the pilots turn when they no longer have air speed data. It is my impression that air speed is very critical to flight management, but pilots can still aviate after the air speed is unreliable.
        My impression is that you were looking for a purely technological solution for redundancy. That does not currently exist. Pilot intervention is always required. How does that translate to a self-driving automotive industry?

        Despite the equivocation you may be reading on this thread, there IS an established procedure for pitot failure resulting in loss of airspeed data, and all pilots are supposed to be taught this and are expected to be proficient in applying it. The procedure involves two stages with different sources of information, but is actually very simple.

        The first stage is done from memory, using what are called Memory Items or Instant Recall Items. Pilots are taught these in type-certification training and are required to have them memorized before taking control of the aircraft. There are only a small number of these trained memorized procedures (around seven on the A330) depending on the operator, comprising the most essential actions needed to stabilize the most common failure scenarios. Aside from Unreliable Airspeed (UAS - loss of airspeed data most often due to iced or obstructed pitots), examples include Sudden Loss of Cabin Pressurization, Rejected Takeoff and Fire Warning. These are scenarios where there may be no time to reference any checklists and where there may be only one chance to get it right: a correct pilot action is needed immediately. It must be done, from memory, and done correctly. The purpose of the memorized procedures is to immediately stabilize the situation without requiring the pilot to improvise.

        In addition to memory, modern glass-cockpit aircraft such as the A330 provide text message instructions including necessary pilot actions, in order of priority, in a specific part of the central cockpit display. On the Airbus jets, this is called ECAM. On Boeing jets it is called EICAS (although neither the 737NG nor the 737MAX has this system).

        The second stage is done from referencing a Quick Reference Guide (QRH) providing instructions for a large variety of failure scenarios. This part is done methodically once the plane is stabilized and there is time to safely do so. This stage provides engineering-derived pitch and power settings specific to the current weight range and altitude range, providing a more accurate and thus safer airspeed estimate. It also assures that collateral systems that might be compromised by the failure condition (steath factors) are reconfigured or shut down. The critical process of task sharing and communication involved in this stage is known as CRM (Crew Resource Management) and requires two pilots with one assigned to flying and one assigned to reading the QRH and working through the checklists. Many accidents occur when CRM breaks down, or is disregarded altogether.

        I've given a lot of thought to how similar automation failures will affect automotive safety in self-driving passenger cars. One thing aviation automation has taught us is that the transition from automation to manual control is one of the most dangerous flight regimes. If that transition is abrupt and unexpected, it can startle and disorient human thought proficiency and result in gross errors of judgment and seemingly unthinkable erroneous actions. It can also introduce steath factors that work against pilot assumptions and expectations. This is the reason pilots must be so intensely trained and tested on rare, abnormal procedures. How are we going to do that with civilian motorists? The answer is, we aren't, we can't. If we were to apply a similar safety standard to automobile licensing, at least half the population would fail to obtain a driver's license (or would lack real-world proficiency on these procedures).

        So, considering this, and considering that all systems must be expected to fail at some rate, and considering the vast number of cars on the roads at any given time, how are self-driving cars going to be considered safe? My impression is that the industry is naively (or conveniently) not considering this at all, and that 'self-driving' cars are, at this stage of human history, just a lot of new accidents waiting to happen. At the very least, critical systems must be entirely fail-operational, such that no driver actions are required to stabilize control of the car in the event of any system malfunction. That level or redundancy is what makes modern airliners so expensive to build and maintain. Are we going to build cars to this standard in a price-competitive, consumer-affordable market? I think not. I think we need to curtail the greed and opportunism that is trying to rush 'self-driving' automation to market, and to give much more time to working out new technologies for safety concerns.

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        • #34
          Originally posted by Evan View Post
          My impression is that you were looking for a purely technological solution for redundancy..
          You must have missed this: (How surprising)

          Originally posted by Jhonmicky
          It is my impression that air speed is very critical to flight management, but pilots can still aviate after the air speed is unreliable.
          I'll repeat- as you and Gabriel stack systems on top of systems, and we already see them interacting in strange ways, I want the poor flawed, slow-operating humans to know how P+P=P and that 16 degree AOA's (which can be independent from pitch) tend to cause stalls in 150s and 340s.

          Originally posted by 3BS
          ...is there anything specific you want me to tell my neighbors at Boeing to see if they can get the suggestion over to the development department? I repeat my concerns that they seem a bit disinterested regarding the subject of software modifications.
          A harsh, dismissive statement. However, it is factual, and it was a failed attempt to say that P+P=P is not a new concept and among all the aeroengineers in the world it has probably been considered. Yet, (per Gabriel) such systems do not exist. Maybe there are good technical reasons (in addition to Gabe's legal ones)? A most interesting argument that planes are built more dangerous, but in a way where you blame the pilots, and not the manufacturer.
          Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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          • #35
            Originally posted by LH-B744 View Post
            Leave the elevator alone, and your aircraft will recover! That's what the experienced AF 447 Flight Captain tried to say, but the newbies called him too late..
            What? By the time the Captain arrived, the plane was in a fully-developed stall and pilot action in the form of downward elevator was MOST DEFINITELY needed. Nor was the left-side F/O's a 'newbie'.

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            • #36
              Originally posted by 3WE View Post
              You must have missed this: (How surprising)
              No, I didn't miss it. I read between the lines. Pilots are required to have special, intense and expensive training, far beyond that of motorists. So, in a similar scenario involving cars, can we provide motorists with the same level of training and proficiency? No. Not even close. Therefore, we need a purely technological, fail-operational solution. Or do you think P + P improvisation is a good idea here as well?

              Comment


              • #37
                Jhonmicky:

                I remember visiting with a light plane pilot (his aircraft lacked pitot heat).

                He departed in some IMC weather and was climbing out.

                He noted he was a little fast so he nosed back a bit.

                A short time later, he was again little fast, so he nosed back a bit more.

                Again, he was a little fast.

                HOWEVER his attitude was a bit nose-high compared to where it should have been.

                BAM: "My pitot tube has iced over!" he realized.

                He called ATC and did a 180 and began a descent with known, robust power and attitude settings and made good use of his attitude indicator.

                As he was beginning an instrument approach, he saw the airspeed needle jump a bit as the ice melted off...He broke out at a nice altitude and landed visually.

                It is probably easier to do in a draggy-light plane at low altitudes than a big huge jet...then again, they do have nice attitude indicators and beaucoup power indications and a book of Acronyms and Power/Pitch settings, or maybe they even initiate occasional descent by hand, no less.

                Anyway- a real example of a real human using the concept of P+P=P to address a pitot issue and living to tell about it.
                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                • #38
                  Originally posted by Gabriel View Post
                  That the memory items came first.

                  As far as I recall.
                  Do you recall me stating (on more than one forum, in fact) that the memory items didn't apply in this case? In fact, I might have even explained (in some detail, too) what the purpose of the memory items for this failure was, but, to refresh your memory, it certainly wasn't anything having to do with an airplane flying FDnH (albeit without a good IAS indication) at FL370.

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                  • #39
                    Originally posted by Evan View Post

                    This is the hostile, dismissive and belittling argument I would expect from insiders like ATL, but you of all people know that this is a discussion forum for the purpose of discussion, for the sake of discussion.
                    Heeeeeey! I fed a homeless kitten six years ago, so hostile my butt!

                    Comment


                    • #40
                      Originally posted by ATLcrew View Post
                      Do you recall me stating (on more than one forum, in fact) that the memory items didn't apply in this case? In fact, I might have even explained (in some detail, too) what the purpose of the memory items for this failure was, but, to refresh your memory, it certainly wasn't anything having to do with an airplane flying FDnH (albeit without a good IAS indication) at FL370.
                      Sorry, I made a mistake. I thought that 3we's was asking if I recalled Evan's position, not yours, and I answered in that way.
                      I don't recall what you said (sorry again, and if you want to explain it beyond what you've just said above, appreciated).

                      I do recall someone (don;t remember if you or somebody else) bringing to the table the fact that the UAS procedure introduced the memory items with "If needed to stabilize the flight" or something like that.

                      And what is FDnH?

                      --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                      --- Defend what you say with arguments, not by imposing your credentials ---

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                      • #41
                        Originally posted by Gabriel View Post

                        And what is FDnH?
                        Fat Dumb n' Happy. (AF447 was not FDnH when the airspeeds were lost).

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                        • #42
                          Originally posted by Evan View Post
                          Fat Dumb n' Happy. (AF447 was not FDnH when the airspeeds were lost).
                          Sure, it was. At least FDnH enough not to mess with. Even if you got a good amount of bumpage happening, that's still plenty FDnH not to go pitching and pulling and Krishna only knows what else. The only "memory item" should have been to leave the airplane be and methodically and deliberately go through the ECAM.

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                          • #43
                            Originally posted by Gabriel View Post

                            I do recall someone (don;t remember if you or somebody else) bringing to the table the fact that the UAS procedure introduced the memory items with "If needed to stabilize the flight" or something like that.

                            And what is FDnH?
                            It was me, and it wasn't "if needed to stabilize flight", it's a rather more forceful "if safety of flight is impacted". The purpose of this memory item is to get you away from the ground, so you can level off and troubleshoot (which is what the memory item ends with), not to start doing things things when you're seven miles away from the ground.

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                            • #44
                              Originally posted by ATLcrew View Post
                              Sure, it was. At least FDnH enough not to mess with. Even if you got a good amount of bumpage happening, that's still plenty FDnH not to go pitching and pulling and Krishna only knows what else. The only "memory item" should have been to leave the airplane be and methodically and deliberately go through the ECAM.
                              I believe that Evan refers to the fact that they had just selected a lower speed to enter the turbulent zone so the A/T had just reduced thrust. The A/T was supposed to add thrust when the selected lower sped was achieved, to keep the plane from keeping losing speed, but with the UAS the A/T disconnected and that would not happen. I remember Evan was concerned that if they didn't set climb thrust (which ironically started by taking the thrust levers OUT of the climb detent) they would stall. Not that I agree with that.

                              Now Evan, googling some I found that ATLcrew is so right that official Airbus documentation explains why they added the "If the safe conduct of the flight is impacted" condition to the memory items and how they propose to train the pilots to specifically NOT apply the memory items unless the safety of the flight is impacted and how that relates to ground/obstacle clearance.

                              Check the date of this document (admittedly, it is for the A320 family but I can see that the A330 UAS procedure in place when AF happened follows exactly the same structure and logic).
                              http://www.smartcockpit.com/docs/Unreliable_Speed.pdf

                              --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                              --- Defend what you say with arguments, not by imposing your credentials ---

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                              • #45
                                I think that Jhonmicky started the fuse and ordered a large bucket of pop-corn.

                                --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                                --- Defend what you say with arguments, not by imposing your credentials ---

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