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Pakistan plane crash: Jet carrying 107 people crashes into houses near airport

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  • #91
    Originally posted by 3WE View Post
    it reflects my bias that intelligent humans generally don't do UBER gross deviations from good practice without some logic and reason.
    Your bias is justified. However, conditional probability.

    When you take intelligent humans in general, most intelligent humans don't do UBER gross deviations from good practice without some VALID logic and reason.

    However, statistically speaking, when you take the subset of humans that were involved in a fatal commercial aviation accident where an unstabilized approach was involved, the numbers start to tend to favor either stupidity, or negligence, or reasons that were no VALID, or simple incompetence. Typically not serious technical issues. Which I don't discard, just judge unlikely.

    And, again, unjustified unstabilized approach happen relatively often. Just that 99.9% of the times the pilots are able to bring it to a good ending. It is the 0.1% what we try to avoid when we prohibit unstabilized approach and mandate a go around if one happens.

    --- 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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    • #92
      Originally posted by Evan View Post
      [If] approach data is real and it was clearly unnecessary getthereitis I will add stupidity if you like.
      Minor edits, but that would probably be valid to do...now we just have to figure out why they wound up high...gross error or a somewhat valid reason...
      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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      • #93
        Originally posted by Gabriel View Post

        Your bias is justified, but also NOT_supported by the lack of problem reports over an extended period AND inquires...
        Fixed to return acknowledgement
        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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        • #94
          Originally posted by Gabriel View Post
          How do you know? I've seen a pilot calling out an item but not really checking it, or accidentally skipping a line, or...


          ... or actually checking the item but doing so wrong, all when in all these cases it was his best intention to do it correctly. I know because it happened to a friend. He told me that it mostly happened with the carb heat (that you would turn on for the descent but need to turn off on final to get full thrust in case of a go around). He also told me that flying a Tomahawk single pilot in the pattern when you are #7 to land in a controlled airport can get your hands full, especially when you have low hours.
          rather than get into a long-winded argument over hypotheticals, i'll simply wait for the cvr to be released then we can discuss. if it turns out that one of them called out, "gear down" or "landing gear" or whatever they are supposed to say and the other replied "check" or "3 green" or any such shit when it wasnt true, i will fly to where you are and buy you dinner and drinks.

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          • #95
            Originally posted by TeeVee View Post
            rather than get into a long-winded argument over hypotheticals, i'll simply wait for the cvr to be released then we can discuss. if it turns out that one of them called out, "gear down" or "landing gear" or whatever they are supposed to say and the other replied "check" or "3 green" or any such shit when it wasnt true, i will fly to where you are and buy you dinner and drinks.
            I suspect the drinks will be on me...

            --- 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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            • #96
              I read that the CVR has been located. The first article also mentions that on the initial attempt, the gear was not down and that the engines struck the tarmac three times.

              https://www.reuters.com/article/us-p...Name=worldNews

              https://www.financialexpress.com/world-news/pakistan-air-crash-foreign-experts-recover-missing-cockpit-voice-recorder-of-crashed-pia-aircraft/1973990/

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              • #97
                This is an example of how an accident like this could happen

                http://avherald.com/h?article=4d7fb6f3&opt=0

                An Bulgarian Air Charter McDonnell Douglas MD-82, registration LZ-LDM performing flight 1T-8115 from Catania (Italy) to Lourdes (France) with 136 passengers and 6 crew, was on an ILS approach to Tarbes-Lourdes-Pyrennees Airport's runway 20, the first officer (39, CPL, 2000 hours total, 1200 hours on type) was pilot flying, the captain (61, ATPL, 24,200 hours total, 6,100 hours on type) was pilot monitoring. The approach was fully stabilized, at 470 feet AGL the first officer disengaged the autopilot but kept autothrust active in SPEED mode maintaining 140 KIAS. Immediately after the first officer switched to manual control of the aircraft strong gusts and rain occurred, the aircraft began to drift left off both localizer and below the glideslope. The captain took control of the aircraft, corrected with a right bank and increased pitch, however, despite autothrust the aircraft continued to descend below the glide. Descending through 100 feet AGL the aircraft was completely out of all parameters for a stabilized approach, significantly below the glide, however, the captain did not call for a go around. Descending through 85 feet the captain disengaged autothrust. At a height of 58 feet the captain increased the pitch from about 4 to 11 degrees and initiated a go around, however, without adjusting engine thrust or activating TOGA, at that point the aircraft was 480 meters before the runway threshold at a height of 40+/-5 feet. The aircraft flew parallel to the ground for about 10 seconds, crossed the runway threshold at 37 feet AGL and 129 KIAS. The first officer, growing increasingly concerned, offered a call "GO AROUND". About 5 seconds later, about 350 meters past the runway threshold, the captain ordered "Go Around" and pressed the TOGA button, but did not notice that autothrust was still off and did not push the thrust levers into the position for Go Around. The aircraft travelled a further 830 meters parallel to the runway with minimal engine thrust nearing angles of attack close to stall. The first officer also did not notice the thruttle levers did not move and thus did not assist to take the engines into TOGA power. The aircraft began to slightly climb, the flaps were reduced from 40 to 11 degrees in one selection, the landing gear was retracted, at 88 feet AGL and 118 KIAS the target altitude for the go around was armed, the target speed selected to 180 KIAS and the spoilers disarmed. The speed reached a minimum of 116 KIAS at a pitch of 15 degrees nose up, the aircraft began to descend again. While disarming the spoilers the first officer noticed the thrust levers were not in the TOGA position, informed the captain and was instructed to set TOGA. At 71 feet AGL and 119 KIAS the thrust levers were aggresively pushed forward, the engines accelerated from about EPR 1.3 to EPR 2.04 (left) and 2.14 (right). At 50 feet AGL, 124 KIAS and 20 degrees nose up the aircraft began to climb again, speed increased and pitch/angle of attack reduced. The aircraft had travelled a total of 1680 meters without sufficient thrust at critical angles of attack.

                --- 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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                • #98
                  did not push the thrust levers into the position for Go Around.
                  It that so hard? Is that so much to ask? I say ban the TOGA button (thank you Airbus). We've seen repeated instances of this and seriously, how much workload is it to move the damned levers. And why is your hand not on the levers anyway?

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                  • #99
                    Automation !!!!!!! Some pilots get so used to it they lose proficiency in flying manually. You know in some wind conditions it's kind of hard to maintain your speed. Auto-throttles let you just concentrate on pitch with one hand and not think about the hand on the throttle. Not Good!

                    I remember years ago when Boeing came out with the B737-300. Southwest bought a bunch of them. They had all the cool horns and whistles. The "then" Chief Pilot required that everyday you had to hand fly one leg. It's a shame that requirement didn't go on as maybe some of these accidents/incidents would never have happened .

                    We'll see when the CVR comes out but, I think I read where this airline hadn't been flying for a period of time, hmm. Then I remember how, before CRM, the FO was afraid to say anything contradictory to the Capt. We all have experiences in our aviation career where for what ever reason, we get behind the airplane. I remember hearing occasionally a pilot asking the tower "did the guy ahead of me make it" during a low vis ILS. It's not what someone else can do but what you can do. Know your own minimums. "Oh hell I'm going around". Remember "There are old pilots and bold pilots but no old bold pilot".

                    Comment


                    • Originally posted by kent olsen View Post
                      "There are old pilots and bold pilots but no old bold pilot".
                      We've got one.

                      I don't think anything here is about proficiency in manual flight. It's about proficiency in automation and, of course, proficiency in judgment. In the incident above that Gabriel just posted, the PF disconnected the autothrust, then expected the TO/GA button to just magically function. That belies a poor understanding of automation. But, yeah, a habit of moving the levers would have definitely helped...



                      Comment


                      • Originally posted by Evan View Post
                        I don't think anything here is about proficiency in manual flight. It's about proficiency in automation and, of course, proficiency in judgment. In the incident above that Gabriel just posted, the PF disconnected the autothrust, then expected the TO/GA button to just magically function. That belies a poor understanding of automation.
                        Not necessarily. It may have been a moment of confusion where he thought that they had the AT still on.

                        There is an AT mode in the MD80 called "CLAMP" where the levers stay wherever you put them. It is used for example to control your rate of climb or descent in IAS/MACH vertical mode. In this mode you basically have manual thrust with the exception that if you change the autothrottle mode (for example to TOGA) then that mode will kick in and the levers will automatically move to the required position. So maybe he thought he was in CLAMP? That said, that mode should not have been in use during the approach, especially not if you had just been flying an ILS with AP/AT since in that mode the AT is set to IAS, CLAMP is not a selectable mode but a mode the AT automatically goes into when you select IAS/MACH vertical mode or, during take-off and go-around, the mode the AT reverts to after setting TOGA thrust. Just saying this to explain how, in your mind and in a moment of confusion, your brain may reconcile the fact that you had just been manually controlling the throttles with the expectation of the AT to kick in and set TOGA.

                        However, what I find amazing in this case, or in the Emirates one, is that the pilots didn't immediately notice the lack of thrust and took action (regardless of the reason and before any analysis of why they were not getting thrust automatically as expected). The change from low thrust during the approach to TOGA is not subtle. It is like the change in the take-off from being lined up and waiting to starting the roll with TOGA. It is a massive acceleration, you get thrown against the seat back and pressed against it.

                        A couple of other things to mention (not applicable for Airbus) is that, even if AT is controlling the speed, it is a good practice to keep your hand on the throttles for 2 reasons, one to get direct tactile feedback of "what it is doing now" (or not doing) and the other to be ready to take immediate action if "what it is doing" doesn't match what you need it to do. THis is especially applicable during final approach and go around.

                        Another thing to mention, is that procedure of TOGA - PITCH UP - TOGA THRUST - FLAPS REDUCTION - POSITIVE CLIMB - GEAR UP in a quick succession. This has caused more than one incident and accident. One of the reasons to start a go around could be too low speed, widhshear, stall warning... In those cases you want to be very careful with the pull up, perhaps, altitude permitting, even delay it until you applied TOGA and the engines are clearly spooling up and the speed is increasing. Same for the flaps reduction. And for the gear up, I would add a check of not only "positive climb" but also "positive speed" (i.e. altitude AND speed bot increasing, or at least positive climb and speed stable at or above a minimum threshold value which could be the same Vref). Positive climb can be easily obtained trading speed for altitude and without really gaining a single joule of energy, rather losing joules. That is not a good place to raise the gear and also could be a good moment to realize that you need more thrust.

                        --- 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 ---

                        Comment


                        • Originally posted by Gabriel View Post
                          A couple of other things to mention (not applicable for Airbus) is that, even if AT is controlling the speed, it is essential to keep your hand on the throttles for 2 reasons, one to get direct tactile feedback of "what it is doing now" (or not doing) and the other to be ready to take immediate action if "what it is doing" doesn't match what you need it to do. THis is especially essential during final approach and go around.
                          Fixed. Actually, I want to put required in there, but...

                          Comment


                          • Hi all. Just watched this:

                            https://www.youtube.com/watch?v=UEYiiZdvNh4

                            The master caution chime heard on the ATC recording could just be due to the airspeed exceeding the speed limits for gear, flaps, etc.

                            Comment


                            • Originally posted by Evan View Post

                              It that so hard [to push the throttles forward]? Is that so much to ask? I say ban the TOGA button (thank you Airbus). We've seen repeated instances of this and seriously, how much workload is it to move the damned levers. And why is your hand not on the levers anyway?
                              Are you feeling OK?

                              Suggesting fundamentals to always have your hand on the throttles and to "think fundamentals"? [Sure, I'm putting words in your mouth but only a FEW words].

                              Contrast that with "the plots not dong their homework on -200 vs 236A" where the TOGA functions differently, but "keeping your hand on the throttles and eye on the airspeed" transcends 172s, sunny afternoon 777's, old 737s in wind shear and MD-80's trying to go around...

                              Is the world ending?
                              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                              Comment


                              • Originally posted by 3WE View Post

                                Are you feeling OK?

                                Suggesting fundamentals to always have your hand on the throttles and to "think fundamentals"? [Sure, I'm putting words in your mouth but only a FEW words].

                                Contrast that with "the plots not dong their homework on -200 vs 236A" where the TOGA functions differently, but "keeping your hand on the throttles and eye on the airspeed" transcends 172s, sunny afternoon 777's, old 737s in wind shear and MD-80's trying to go around...

                                Is the world ending?
                                On top of that, it is not like Airbus didn't have its share of TOGA screw-ups during go around.

                                I remember at least 2 cases (sorry, I don't remember the details) of Airbus pilots failing to fully advance the throttles to TOGA (they advanced them ALMOST to TOGA) which made the plane not go to TOGA mode (i.e. not select the TOGA speed, climb profile, altitude, flight director commands, etc) which made these planes almost crash when the pilots were fast to trust that the automation would take care and slow in recognize that it was not taken care.

                                Not to mention that one of the hypothesis in this Pakistan crash (I don't think it is the most likely one but let's wait see) involves the pilots going around and retracting the gear but forgetting to add thrust and settling back on the RWY (i.e. same scenario than Emirates and than the MD-80 above).

                                --- 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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