Announcement

Collapse
No announcement yet.

Lion Air crash in Bali

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Originally posted by Fear_of_Flying View Post
    I'm going to go with that very useful catch-all phrase as the most likely culprit, lack of situational awareness. Someone lost track of altitude, speed or position, not because they fell asleep, but quite the opposite, because they were stressed out and not keeping their head.
    I can see a loss of situational awareness that led to loss of control, like in Turkish.

    I cannot imagine a loss of situational awareness that led to a CFIT. Not in visual conditions with the runway fully in-sight. I meant, the RA saying "one hundred, fifty, forty, thirty, twenty, ten" should be an unbearable temptation to look out to see if the runway is still out there. (it would not be the first time that a pilot is able to do something that I can't imagine being possible, though).

    --- 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


    • #47
      Originally posted by Gabriel View Post
      Maybe you are used to some airplane with binary control (full up, full down)...
      Ooooo.....Insulting!

      You are glossing over two things:

      1) The plane was encountering lots of turbulence.

      2) Big planes have a ton of inertia (is there another post about that somewhere?)...pilots tend to put big control inputs in to adjust attitude. Just watch some of those Youtubes of cross wind landings- the control surfaces are very active in both directions with significant deflections.

      When your butt is not sitting there dealing with 70 kt wind shears, it's easy to judge that someone shoved forward a bit too much and a bit too long...Yeah, I see where you say negative G's, but I've felt negative Gs in a Jetsream 31 on a clear day with white puffy clouds and windy, but not extreme conditions.

      I acknowledge that this is not a black and white deal- I seem to recall that someone attempted to give "unprepared" pilots a simulated version of the windshear and most survived.

      On the other hand, I belive a pilot named Naviator 5 from a forum long ago, reported that the training exercise has you tree-top high, with genuine butt-hole pucker and a need for critical conrol management. (And let's not forget that the simulator cannot simulate a lot of the movements 191 did)
      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

      Comment


      • #48
        Originally posted by NTSB
        Airplane Control During Microburst Penetration

        Delta and most major air carriers taught their flightcrews to trade airspeed for altitude if they inadvertently encountered low-altitude windshear. This technique was practiced in the simulators, including the L-1011 simulators, and flightcrews were taught to increase the airplane’s pitch attitude and to add maximum thrust if necessary to control the airplane’s flightpath.
        If necessary to avoid ground contact, the pitch attitude could be increased until the stickshaker activated and then decreased slightly to an attitude which would silence the stickshaker. Thereafter, the airplane’s pitch attitude should be kept at an attitude just below that which would reactivate the stickshaker until the end of the windshear area was traversed.

        The first officer was apparently able to apply the above techniques to keep the airplane on the ILS glideslope as it passed through and beyond the initial portion of the microburst. When the airplane descended into the vortex, the combination of an airspeed loss of 20 KIAS and a strong updraft most likely caused a momentary (1-second) activation of the stickshaker. The Safety Board believes that the first officer acted reflexively when the stickshaker activated to exert a 20- to 25pound forward push on the control column. This control column force and the longitudinal stability of the airplane resulted in the airplane nosing over to a -8.5° pitch attitude, a rapid departure from the ILS glideslope, and a descent rate which approached 5,000 fpm for an instant. [and this was during a strong updraft!!!]
        Don't misunderstand me. I am not blaming the pilot. He had a lot of things against him, to name a few:
        - There was not so much awareness and understanding of windshears back then as there is now.
        - The windshear training was in its infant stages.
        - There were no reactive and preventive on-board windshear alerts as there are now.
        - The PFD had not pitch limit indicator as they have now.
        - The flight director cues did not follow a widshear profile during a windshear. They just remained commanding the mode selected in the AP.
        - The ground equipment was not so good for early detection of windshears.
        - And last but not least, the plane was shaking like a cocktail shaker.
        And also, he displayed a great airmanship by keeping the plane closely on the glide slope when he flew through the core of the microbrust and the strong headwind draft turned into a strong downdraft and then a strong tailwind draft.

        The part where I disagree with you is where you use terms like "the pilot should maybe think of maybe lowering the nose just a little bit" in contrast to Air France or Colgan, or that "the pilot was bit reluctant to pull up" in Delta. It makes it sound like the pilots just didn't lower the nose a bit in AF and Colgan when what they were doing was applying full back control inputs in response to a stall, or that the Delta pilot was a bit reluctant to pull up when in fact he was applying a 20 to 25 lb push down force.

        Next thing is that Pamela Anderson is maybe just a tad not virgin enough.

        --- 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


        • #49
          Preliminary Report into the Lion Air crash at Bali. Interesting reading.
          Aviation Herald - News, Incidents and Accidents in Aviation




          Comment


          • #50
            The NTSB reported the captain (48, ATPL, 15,000 hours total, 7,000 hours on type) was pilot monitoring, the first officer (24, CPL, 1,200 hours total, 923 hours on type) was pilot flying.
            That's a lot of experience in the 737 for the captain and not that bad for the FO, who however had only 277 hours TT when he started flying the 737.

            The aircraft positioned for the VOR/DME approach to runway 09 with MDA at 465 feet AGL (editorial note: the chart by AIP Indonesia identifies MDA at 465 feet MSL and 454 feet AGL). While descending through 1600 feet the aircraft was cleared to land on runway 09 by Tower who reported winds from 120 degrees at 5 knots.

            According to the flight data and cockpit voice recorders the aircraft was descending through 900 feet AGL when the first officer stated the runway was not in sight.

            37 seconds later the aircraft descended through 550 feet AGL, the EGPWS called "MINIMUMS", the autopilot and autothrottle were disconnected and the descent was continued.

            At about 150 feet AGL the captain took over control of the aircraft, the first officer acknowledged and stated he could not see the runway. 8 seconds later the EGPWS called out "TWENTY", the captain commanded "Go Around", one second later the aircraft contacted the water surface
            Busted minimums + CFIT.

            That, or... nah...

            --- 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


            • #51
              Originally posted by Gabriel View Post
              Busted minimums + CFIT.
              NTSC's final report:

              - The aircraft flight path became unstable below minimum descends altitude (MDA) with the rate of descend exceeding 1000 feet per minute and this situation was recognized by both pilots.

              - The flight crew loss of situational awareness in regards of visual references once the aircraft entered a rain cloud during the final approach below minimum descends altitude (MDA).

              - The PIC decision and execution to go-around was conducted at an altitude which was insufficient for the go-around to be executed successfully.
              There is other interesting stuff: Highly variable weather condition, not timely informed by the ATC to the flight crew, which included shifting winds, turbulence and rain showers. Or the pilot deciding to continue the approach after the FO said he had lost sight of the runway because the PIC said he still could see the flashing approach lights, which were in fact off.

              --- 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


              • #52
                Originally posted by Gabriel View Post
                NTSC's final report:



                There is other interesting stuff: Highly variable weather condition, not timely informed by the ATC to the flight crew, which included shifting winds, turbulence and rain showers. Or the pilot deciding to continue the approach after the FO said he had lost sight of the runway because the PIC said he still could see the flashing approach lights, which were in fact off.
                A senior PIC with 15,000 flight hours and another blatant case of get-there-itis trumping stabilized approach criteria. I guess you just can't teach an old dog new tricks. So I expect this will keep on happening until operators learn how to do that.

                Comment


                • #53
                  Originally posted by Evan View Post
                  A senior PIC with 15,000 flight hours and another blatant case of get-there-itis trumping stabilized approach criteria. I guess you just can't teach an old dog new tricks. So I expect this will keep on happening until operators learn how to do that.
                  And yet, these things don't stop amazing me.

                  In this case, at 900ft the FO said that he had lost sight of the runway but the PIC said that he had a non-existent flashing approach light in sight. At 650ft, the GPWS calls minimums. Then five hundred, four hundred, three hundred, two hundred, then the PIC says "my plane" and the FO acknowledges "your plane, I can't see the runway".

                  I can't understand in a situation like this that the control is taken over for anything but to go-around. Even if due some kind of magical situation the PIC had in sight the runway that was invisible to the FO, you can't (or shouldn't) continue the approach with the FO out of the loop.

                  But no: One hundred, fifty, forty, thirty, twenty and only then the pilot calls for a go-around. Of course they were in the water one second later.

                  Two final thoughts.

                  Unlike the US-AIR "miracle of the Hudson", this airplane contacted the water with a slightly negative pitch attitude and at more than 1000fpm of sink rate. The plane remained largely intact and only 4 persons were seriously (but not critically) injured, and all evacuated by themselves. Man, those toothpaste tubes are tough.

                  All in all, and given that the crew didn't initiate the go-around in time to prevent ground contact (not to mention when the approach become unstabilized because they exceeded 1000ft of vertical speed below minimums, not to mention when they busted minimums by continuing the approach without the runway in sight at minimums or having lost visual contact with it below minimums), all these people were very lucky that the crew initiated the go-around so late. The airplane stopped bare meters short of the sea wall. Had they initiated the go-around a couple of seconds earlier, we could be talking about a plane smashed against the sea wall rather than a somehow controlled ditching.

                  --- 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


                  • #54
                    So Gabriel's post on 4/14 was pretty close:
                    Originally posted by Gabriel View Post
                    Dual engine failure due to:
                    - Birds
                    - Fuel exhaustion / mismanagement
                    - Mismanaged single engine failure (wrong engine shut down)
                    - Fish

                    That's not going to look good on a resume!
                    Be alert! America needs more lerts.

                    Eric Law

                    Comment


                    • #55
                      Originally posted by Gabriel View Post
                      Two final thoughts.

                      Unlike the US-AIR "miracle of the Hudson", this airplane contacted the water with a slightly negative pitch attitude and at more than 1000fpm of sink rate. The plane remained largely intact and only 4 persons were seriously (but not critically) injured, and all evacuated by themselves. Man, those toothpaste tubes are tough.

                      All in all, and given that the crew didn't initiate the go-around in time to prevent ground contact (not to mention when the approach become unstabilized because they exceeded 1000ft of vertical speed below minimums, not to mention when they busted minimums by continuing the approach without the runway in sight at minimums or having lost visual contact with it below minimums), all these people were very lucky that the crew initiated the go-around so late. The airplane stopped bare meters short of the sea wall. Had they initiated the go-around a couple of seconds earlier, we could be talking about a plane smashed against the sea wall rather than a somehow controlled ditching.
                      Not to mention negative pitch and > 1,100fpm below 50'... The report findings state that the pitch and N1 levels indicate a basic violation of flight principals, apparently using pitch for speed on short final... trading VS for airspeed?

                      But yes, ahh, the irony. Damned by pilot error, saved by pilot error.

                      And given the fact that this thing struck not only the water at about 18fps but also a coral reef, it's remarkably intact.

                      Comment


                      • #56
                        My guess is that the PIC had committed to landing, passing 50', the point where you are committed to land by the LAWS OF PHYSICS, without calling for go-around, and that he just uttered the words "go-around" at 20' instinctively, i.e. instead of calling out "mommy" or "ho lee fuk".

                        Comment


                        • #57
                          It sounds to me like he was committed the whole time, and for whatever reason could not bring himself to reverse that decision - no matter what. When they reached minimums at 650 feet the approach should have been called off, but his mental commitment to landing was so great that he imagined he could see the approach lights just to justify continuing (this is where Gabriel jumps in and cites "confirmation bias" ).

                          But on your other point, I would argue that under normal circumstances, the laws of physics will never force you to commit to landing. Even when the wheels have contacted the runway you can throttle up and become airborne again. Whether or not you call that a "landing" or a "missed approach" is a matter of semantics.

                          Of course note that I did mention "normal circumstances" above. If your wheels are in the water instead of on pavement, your options for continuing the flight may be more limited.
                          Be alert! America needs more lerts.

                          Eric Law

                          Comment


                          • #58
                            Originally posted by Evan View Post
                            My guess is that the PIC had committed to landing, passing 50', the point where you are committed to land by the LAWS OF PHYSICS, without calling for go-around, and that he just uttered the words "go-around" at 20' instinctively, i.e. instead of calling out "mommy" or "ho lee fuk".
                            At 50ft a go-around with no touchdown is perfectly viable, if the airspeed is healthy (as it was in this case) and the sink rate is normal (it was a bit too high in this case, but my guess is that it was still perfectly viable).

                            The flare is started below 50ft, and many times the airplane flies parallel to the runway for a short while before touching down, and others they even baloon a bit gaining a bit of altitude again, and that was after idling the throttles and just a slight pull-up.

                            What I can't imagine is listening "three hundred, two hundred, one hundred..." , not having the runway in sight, and continuin the approach.

                            I don't know if I would have had the balls to do it, but the FO, instead of pasing the controls to the PIC saying "I can't see the runway", should have firewalled it, pulled up and said "go around". Let the PIC protest after the fact.

                            --- 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


                            • #59
                              Originally posted by Gabriel View Post
                              At 50ft a go-around with no touchdown is perfectly viable, if the airspeed is healthy (as it was in this case) and the sink rate is normal (it was a bit too high in this case, but my guess is that it was still perfectly viable).
                              ...and you are over land on the runway heading...

                              How is < 50' go-around viable when you can't see the threshold?

                              I don't know if I would have had the balls to do it, but the FO, instead of pasing the controls to the PIC saying "I can't see the runway", should have firewalled it, pulled up and said "go around". Let the PIC protest after the fact.
                              He should have pushed the TOGA button. Do they know about this button?

                              Comment


                              • #60
                                Originally posted by Gabriel View Post
                                I don't know if I would have had the balls to do it, but the FO, instead of pasing the controls to the PIC saying "I can't see the runway", should have firewalled it, pulled up and said "go around". Let the PIC protest after the fact.
                                Wasn't there some well-known accident where the FO did exactly that, and I'm not sure if the captain said anything but he physically overrode the decision - grabbed the throttles and pulled them to idle and shoved forward on the yoke to attempt to land?
                                Be alert! America needs more lerts.

                                Eric Law

                                Comment

                                Working...
                                X