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  • Ok guys, to be fair: Asiana admits that the crew failed to do their job. But they said that Boeing helped in that fail. I copy-pasted fragments that show the last part only, but told you to go to AvHerald to get the full story.

    Here is a fragment of the "full picture": This is a sort of accident investigation report made by Asiana themselves:

    The probable cause of this accident was the flight crew’s failure to monitor and maintain a minimum safe airspeed during a final approach, resulting in a deviation below the intended glide path and an impact with terrain. Contributing to this failure were (1) inconsistencies in the aircraft’s automation logic, which led the crew to believe that the autothrottle was maintaining the airspeed set by the crew; and (2) autothrottle logic that unexpectedly disabled the aircraft’s minimum airspeed protection.

    Significant contributing factors to the accident were (1) inadequate warning systems to alert the flight crew that the autothrottle had (i) stopped maintaining the set airspeed and (ii) stopped providing stall protection support; (2) a low speed alerting system that did not provide adequate time for recovery in an approach-to-landing configuration; (3) the flight crew’s failure to execute a timely go-around when the conditions required it by the company’s procedures and, instead, to continue an unstabilized approach; and (4) air traffic control instructions and procedures that led to an excessive pilot workload during a high-energy final approach.
    I fully agree with the bolded parts. I don't have enough info to judge the last sentence about ATC (but of course that the pilot can always, and MUST if needed, say "unable"). The rest is, in my not-so-humble opinion, BIG TIME ROTTEN DIARRHEA BULLSHIT.

    Now, let me explain why in more detail. Most of the explanation below has nothing to do with the Asiana accident, except that you need to understand the big picture to properly manage each mode, including the one used by the Asiana crew. You cannot properly understand just a part of it and expect to use it correctly. In the same way that you cannot just learn the use of the yoke and then say "ok now, let's move to the throttle class".

    Let me warn you that this will be a very "Gabriellian" thread.

    There are two basic categories of AP modes for the pitch channel:
    1- Pitch controls altitude.
    2- Pitch controls speed.

    The first mode has a good control of the vertical path. The second, used together with other tools and methods, help optimize the operations.

    So, if you want to hold the altitude, climb or descend at a specific climb rate, of follow the glide slope of an ILS or other approach with vertical guidance, which mode will you use? Pitch controls altitude.

    If you want to climb to cruise at the optimum cruise power and speed, or make a descent with he engines idled, or get the max climb performance with full thrust and best-climb speed, which mode will you use? Pitch controls speed.

    There are several modes within the "pitch controls altitude" group.
    - Altitude hold: The AP will command pitch to hold the selected altitude and correct any deviations from it. If you are flying in another mode (including manually) and then select "altitude hod" then the selected altitude is automatically set to your current altitude.
    - Vertical speed: The AP will command pitch to keep the selected vertical speed and correct any deviations from it. In this mode you will also set a target altitude, which will hopefully be consistent with your selected vertical speed (like a lower altitude of you selected a negative vertical speed). When approaching the target altitude, the AP will revert to "Altitude hold" by itself.
    - Glide slope: The AP will command pitch to track the glide slope and correct any deviations from it.

    Note that, traditionally, the AP will try hard to follow your command. Too hard.
    It will, for example:
    - Attempt to fly through the ground if you are descending in vertical speed and the selected target altitude is below the elevation of the terrain.
    - Overspeed the plane of you select a sink rate that is too high for the currently applied thrust.
    - Stall the plane in an attempt to keep the selected vertical profile when the thrust applied is not enough to sustain it. Examples are Turkish at Amsterdam where they were in "glide slope" mode with the engines at idle and the plane increasingly pulled up to try to keep the glide slope with a deteriorating airspeed, until it stalled, and the Pinnacle crash ("let's four oh' one it, dude, and gimme a diet pepsi") where even max thrust was not enough to keep a healthy airspeed a that altitude, but the AP insisted with his "altitude hold" command and stalled the plane at 41000ft.

    Pilots need to understand that the AP is not there to do their jobs. The pilots are still responsible to ensure the flight path. The AP is there to follow the pilot's commands so he is relieved from some workload and has more time to concentrate on ensuring that the plane is doing what he wants. The difference between an AP and a co-pilot is that the copilot will hopefully not fly through the terrain or stall the plane if the captain tells him to do so, and will instead hopefully question the captains orders or advise "sum tin wong". A copilot is a crewmember with whom CRM is possible and expected. The AP is a stupid machine that won't question the pilot's stupidity and will gladly destroy himself in a fiery crash to honor the commands given to it.

    The "pitch controls speed" family of modes is in fact just one mode: Speed hold: The AP will adjust the pitch to keep the selected airspeed (or Mach number).

    For example, say that you are flying in the "altitude hold" mode and have a thrust that keeps a constant airspeed. Now you select "Speed" mode. What will the plane do? Nothing. With the current altitude and thrust the AP was actively holding the altitude constant but the speed was also stable, so now actively holding the airspeed means that the altitude will be stable.

    Now, if from this stable state you:
    - reduce the thrust, the AP will pitch down to hold the airspeed.
    - increase the thrust, the AP will pitch up to hold the airspeed.
    - increase the selected speed, the AP will pitch down to increase the airspeed.
    - reduce the selected speed, the AP will pitch up to reduce the airspeed.

    In this mode you also enter a target altitude, hopefully different from your current altitude and hopefully consistent to the maneuver you are about to perform (a lower altitude if you are about to descend). When the altitude approaches the selected target, the mode again automatically reverts to "altitude hold".

    This is the mode the Boeing calls FLCH for "Flight Level Change", because you use it (among other things) at cruise to change your cruising flight level without changing your speed.

    In a time where the FMS managed the horizontal aspect of the flight navigation) but not the vertical path (no V-NAV), it was much more used for other things too. I will go back to that later.

    Did you see all the times that I've said "AP" above. Well, delete them. I did it for simplicity, but in fact it's the "FD", "flight director". The "flight director" shows in the attitude indicator the control inputs that the pilot needs to do (pull up, push down) to achieve the desired performance (i.e. the values that you entered and the mode you selected). "The pilot needs to do" here means the human pilot or the auto pilot. The human pilot will typically try to follow the flight director's commands because he knows that this assured the desired performance. But he can also choose not to follow it for whatever reason (for example, realizing that the result is not what he expected). The AP will simply obey the flight director's commands.

    Now, all that is the Auto Pilot (AP). What about the Auto Throttle (AT, also Auto Thrust)?
    I didn't mention it because of one good reason: all of the above applies with and without AT. In fact, there are many planes with APs that have all the above modes and are not even fitted with an AT.

    Now, the AT also have different modes which I will also divide in two categories: "throttle controls speed" and "throttle controls thrust".

    The "throttle controls speed" category is the most obvious one and has only one mode that does what it's name says: Speed hold. It adjusts the throttle to hold the selected airspeed (or Mach number). It's the equivalent to the "cruise control" in cars.

    In the "throttle controls thrust" category we have different modes:
    - Hold a given engine parameter: For example, hold a given N1 (which is a fancy name for RPM).
    - Hold a performance thrust: For example, hold take-off thrust or climb thrust or maximum continuous thrust. This is quite similar to the previous one, except that the engine parameter is automatically computed. For example, the N1 for the take-off thrust depends on ambient temperature. So the pilot can look up the correct value for today's conditions and select "hold this N1" or, more simply, select "hold take-off thrust". In some planes, in facts both modes are the same one. The AT will hold a N1 that is shown in a window. Now, that N1 can be manually entered by the pilot or the pilot my chose "show the take-off N1". The AT doesn't care and will just hold whatever N1 is shown.
    - Do nothing (I will cal this mode "clamp"): Now, this is tricky. What is the difference between this and "AT off"? The only difference is that the AT will remain engaged, but doing nothing whatsoever, until some specific criteria is met. Then it will "wake up", "kick in" and start doing things. More on this later.

    Now, what happens if you select the "speed" mode both in the AP and AT? That shouldn't be done. Only one of them should be trying to hold the speed, or they would be fighting between them.

    But there are good news: The engineers are not that stupid, so while the AP and AT are two different systems, there is communication between them, and selecting the "speed hold" in one of them will revert the other one to some other mode (if it was in "speed hold" too). There is more communication and coordination between them.

    Let me give you an example of a very simplified full flight in an MD-80 (which is the system I know best). The names will be different in other planes but the concepts will be basically the same.

    So the flight, of which I will concentrate only in the vertical profile, is this:
    Take off, climb at V2+10, level off at 1500ft, accelerate to 250 while cleaning up, climb to 10000ft at 250, climb to 20000 at 270, cruise at 290, descend to 10000ft at 270, descend to 2500 ft at 250, slow down to Vapp while configuring for landing, follow the glide slope and land.

    Here we go:

    I'm lined up. The AP and AT are off.
    I select "TO/GA" in the Thrust Rate Computer. The correct N1 for take-off thrust appears in a window. In the AT I select the "Hold N1" function, but the AT remains off.
    In the AP (in fact, in the flight director) I select 1500ft. The AP also remains off.
    I advance the throttles levels to achieve a N1 value that is close to the N1 shown in the window, then I engage the AT which will follow the "N1 hold" mode already set, and adjust the throttle levers to keep that N1 value shown in the window: Take off thrust.
    Vee one, rotate, positive climb, gear up. While the plane accelerates, I slowly increase the pitch do diminish the acceleration until I stabilize the plane at V2+10 with about 15 to 20° nose-up attitude (depending on the weight and ambient conditions).
    Now I engage the AP in "speed hold" mode. So by now, the AT will hold take-off thrust and the AP will adjust the pitch to hold V2+10.
    But remember that I had already selected a target altitude of 1500ft.
    When we approach 1500ft, the AP will automatically revert to "altitude hold" and the AT will automatically revert to "speed hold".
    So I now select 250 in the AT and the AT increases the thrust to increase the speed while the AP adjust the pitch to keep 1500ft.
    As the plane accelerates I start retracting the flaps and slats. The AP makes many pitch corrections to keep 1500ft with all these configuration changes and increasing speed.
    The plane will approach 250kts and the AT will reduce the thrust to hold it. Eventually, the plane will stabilize with the AT holding 250 and the AP holding 1500.
    Then, I change the AP mode to speed hold at 250, the AT automatically reverts to "clamp" (stops playing with the thrust levers).
    Now I select at target altitude of 20000ft and... ta-da!!!! Nothing happens. The plane remains at 250 and 1500.
    Ok, now I select "climb thrust" in the thrust rate computer, the correct value of N1 for climb is shown in the N1 window, and now yes... nothing happens.
    Now I change the AT mode from "clamp" to "N1 hold". Finally, the AT starts playing with the throttles, increases thrust to hold the selected N1 (which, remember, was the N1 calculated by the thrust rate computer) and the speed will tend to increase, but the AP will prevent that by pitching up.
    The plane will achieve a stable climb at climb thrust and 250 kts. And at what vertical speed? Whatever makes the plane hold 250kts. The AP is not caring of vertical speed but speed itself.
    When we cross through 10000ft I slowly start to increase the selected speed in the AP to 270. The AT will lower the nose a bit to let the speed increase to 270 and then will pitch up a bit again to hold 270 for the remaining of the climb. Why did I say "slowly increase the selected speed"? Remember I commanded to the AP "you will adjust the pitch to hold the speed I tell you". If we are at 250 and suddenly I tell the AP "now adjust the pitch to hold 270", the "lower the nose a bit" may become more than "a bit". The AP might lower it enough that the plane might actually descend as it builds speed. Nothing serious anyway. As the speed approaches 270 the AP will raise the nose again to stabilize in a 270 kts climb. The "slowly" part was for the sake of smoothness only.
    When the altitude approaches 20000ft, the AP will revert to "altitude hold" and the AT will revert to "speed hold".
    Now I set 290 in the AT and the plane stabilizes at cruise with the AP holding 20000 and the AT holding 290.
    After a while at cruise, it's time to descend.
    I change the AP mode to "speed", the AT reverts to "clamp", select a target altitude of 10000 and nothing happens.
    So I manually retard the throttles all the way to idle and the AP commands nose down to keep the speed.
    I slowly reduce the selected speed in the AP to 270 (again, "slowly" to prevent that the AP actually climbs to reduce the speed quickly), and the plane finally stabilizes in a descent at idle and 270. At what vertical speed? Again, whatever it happens to be the only vertical speed that makes this happen.
    Note that now I selected 10000ft as target altitude, but I had not selected the intermediate 100000ft as a target altitude during the climb. The reason is that, during the climb, I have no problem to cross 10000ft at 250 and then accelerate to 270 while climbing. But now want to make sure I won't descend below 10000ft with a speed above 250 because I'd be violating the "250 max below 10000ft" speed limit.
    When the plane approaches 10000ft, the AP reverts to "altitude hold" and the AT reverts to "speed hold", but I override it by pulling and keeping the throttle levers to idle. So the plane levels off at 10000ft and, with the throttles levers kept at idle by my hands against the wishes of the AT, the loses speed.
    When the speed reaches 250 (because, unlike Asiana pilots, I AM monitoring the speed) I select "speed hold" in the AP and the AT reverts to "clamp".
    Now the AP will lower the nose to keep the speed at 250kts. And I don't need to fight against the AT anymore to keep the levers at idle.
    The plane will stabilize in a descent at idle and 250kts.
    Now I set a target altitude of 2500ft.
    When the plane approaches this altitude, the AP will revert to "altitude hold" and the AT will revert to "speed hold", and the plane will stabilize with the AP holding 2500 and the AT holding 250.
    Ladies and gentlemen, we will be landing in a few minutes. Fasten your seatbelts, close your trays, and put your seat-backs in the vertical position.
    Now I select Vapp (say 140kts) in the AT.
    The AT reduces thrust to slow us down, and as we do I start extending the salts and flaps in steps and also lower the landing gear.
    When we are close to 140kts, the AT adds thrust and the plane stabilizes at 140kts and 2500ft.
    I see that the glide slope needle of the ILS comes alive. I select the glide slope mode in the AP but nothing happens yet. The glide slope is just armed, but since we are not tracking the glide slope yet the active mode remains "altitude hold".
    As the glide slope needle approaches the center, the AP mode reverts to "glide slope" and the AP starts to adjust the pitch to keep that needle centered. The AT remains in "speed hold", so it will retard the throttles a bit since less thrust is needed to keep 140kts while descending in the glide slope than what it was needed to hold the altitude.
    Perfect, we are stabilized in the glide slope. Now I will select a target altitude of 4000ft. No, I'm not crazy and the AP will ignore it, at least by now. It's the altitude we have to climb in the event of a go-around.
    We complete the landing checklist and get the tower clearance to land.
    You might not note it, but I am closely monitoring the ILS and the speed and I am ready to immediately disconnect the AP and AT and take manual control if these parameters don't stay where they should. I even have my hand on the thrust levers to have a tactile cue of what the AT is doing and to be able to quickly firewall the throttles if needed.
    We are in visual conditions, so our stabilized approach gate is 500ft, and we are approaching this altitude right now.
    Let's see:
    Aligned with the runway? Check.
    Speed stable at Vapp (which is not the same than "crossing through Vapp")? Check.
    Stabilized in the glide slope (which is not the same than "crossing the glide slope)? Check.
    Thrust stabilized in an "approach" value, and specifically NOT in a very low value (like idle) from where we know that it would take too long to spool up? Check.
    Airplane configured for landing? Check.
    Landing checklist completed? Check.
    Are we cleared to land? Check.
    Ok, we go.
    I am about to disconnect the AP to manually complete the landing (I plan to leave the AT on so I only need to monitor the speed but don't need to control it, and I will override it by pulling to idle during the flare), but then the tower calls: "There's a cow in the runway, go around".
    No problem. I click the "go around" buttons. The AT and AP enters "go around" mode which basically is AT goes to "Take-off thrust hold" mode and the AP goes to "go-around speed hold" mode. I follow with my hand how the AT firewalls the throttles and I monitor the AP pulling up to keep Go-Around speed. Flaps 15. Take-off thrust check. Positive climb, gear up.
    Now, remember that target 4000ft that we entered a few minutes ago? There we go. When we approach 4000ft the AP will revert to altitude hold and the AT will revert to speed hold. And we are ready for a second try. Don't worry, I'll not go through it.

    There were some simplifications there, but I hope that now we all have a good understanding of the concepts and philosophy behind the design of these AT and AP systems. The big picture.

    Now let's move to Asiana.

    The pilot is in a long final and finds himself higher and faster than he would have liked to. What are his options?
    - Go around.
    - Requesting a descending 360 turn.
    - Try to correct the situation while continuing the approach.

    The pilot opted for the last one. I am ok with that, but don't blame the ATC for this because you had the other 2 options. A pilot is never compelled to follow ATC instructions that he feels are not safe, including if that feeling is due to own limitations rather than technical ones.

    So how would a pilot try to correct the situation? Let's see: it's a visual, long straight-in approach in a perfect day with excellent visibility and nearly no winds? I'd likely turn everything off and, manually fly the beast and, if I don't like how it's going, I'll go around.

    A second option would be to disconnect just the AP but leave the AT set in "speed hold" and selecting lower speeds (all the way down to Vapp) as we "dirty" the plane by extending slats, flaps and landing gear. But I have to be careful because if I pitch down too much to try to descend to the "good" descend profile, the AT might be unable to keep the selected speed even with the throttles at idle and I might bust some flaps speed.

    A third option would be to use the "speed hold" mode (FLCH) in the AP (the AT reverts to "clamp") and pull the throttles back to idle. This is what the Asiana pilot did and, unlike many, I actually like it. A lot! You can just select Vapp in the AP and, as the speed goes down, you start dropping slats, flaps, gear, speedbrakes, the anchor, all what you have. You don't need to care about the speed because the AP will first keep the nose up to slow down to Vapp, and then lower the nose as much as needed to keep Vapp (well, you DO need to care about it and monitor it, but as long as it's doing what you expect you don't need to "manipulate" it). If THAT doesn't correct the situation, then NOTHING will and it's time to go around. And if it works, when you are in the path you wanted you select "speed hold" in the AT and "vertical speed hold" in the AP and make small adjustments in the selected vertical speed to keep the desired descent slope until you finally disconnect the AP and manually land the plane (you can leave the AT on in "speed hold" mode if you want).

    But... the Asiana pilot did one more thing: He disconnected the AP.
    Now, I know that I have just presented two first courses of action that included disconnecting the AP. But in this third option, doing it is really way too stupid. Think of it:

    You tell the system: Autothrottle, forget about the speed. Autopilot, you have the speed. And next you disconnect the autopilot? So who is in charge of the speed now? YOU. Okay, we are now in the first scenario, the pilot is in full manual flight. I am okay with that. That was my first option after all. But if you are going to take full manual control of the plane, why select FLCH in the AP (only do next disconnect the AP) which causes the AT to go in "clamp" mode and leave the AT engaged in a mode that basically means "do nothing"?
    AND YOU STILL EXPECT THAT THE AT WILL KEEP A SPEED?????
    Again: By selecting the FLCH ("speed hold" mode) in the AP, you have just told the AT "forget about the speed" and told to the AP "you have the speed". And then, killed the AP.
    Do you realize the magnitude of the stupidity of this?

    If you want to take full manual control, better disconnect everything, right?
    But no, this pilot's intention was not to take full manual control. Apparently, his intention was to override the AP to pitch down more steeply and he expected that the AT will take care of the speed (yes, he have just told the AT exactly the opposite, but it seems that he didn't understand what he was commanding by selecting FLCH).

    So, why did the pilot thought that the AT would take care of the speed?
    Nothing in all this explanation so far said anything about the AT taking care of the speed when not in "speed hold" mode, and in many planes this is the end of the history. However, the 777 adds an additional safety layer: If the speed goes too low, the AT will add thrust to keep the speed and prevent a stall.
    This additional safety layer is not required by regulations and that many planes don't have it.

    So the pilot was using a last-resource back-up safety feature to operatively control the speed. But there is one thing that he didn't take into account: this feature is inhibited when these two conditions are met at the same time: the throttle levers are at idle AND the plane is below 100 ft above the ground. Why? Because when the pilots flare the plane for landing, they are below 100ft, they pull the throttles to idle, and they do it precisely because they WANT the speed to go down and become what would be "too low" for normal flight.

    Look at the videos and animations of the Asiana crash. It would have been a perfect and smooth landing, except that the runway was 2000ft farther. How on Earth could have the AT known that the pilot was not in fact flaring to touch down on a runway that began 2000ft earlier than the actual runway?
    The crash was so close to the actual runway, that even the EGPWS (enhanced ground proximity warning system), which is specifically designed for this, couldn't detect that it was landing short of the runway and hence triggered no warning.

    So Boeing adds a last-resource back-up safety layer that works exactly as designed but not as the pilot (and Asiana) expected, and now Boeing is sued for such system. If I was Boeing I'd say "You know what? I should have not added it. All operators must disable this function and it will not be included in airplanes coming out of the factory".

    It happens all the time: The manufacturers add additional safety features that are not required and then they get in trouble when the operators abuse them. And then the people (and the operators) ask "but why don't add this feature to the feature to prevent this, and then this other feature in case we abuse from the new additional feature in some other way, and then..." And the answer is "because each additional feature that I add is abused by you and then you blame me for it". The manufacturers could add much more safety features but they don't because of this reason.

    Let me make an analogy: I manufacture inflatable life vests. These life vest have two independent chambers with two independent gas bottles to inflate them. One chamber is enough to keep you afloat. But the vest is designed with this redundancy in case one chamber leaks or one bottle fails.

    Now you have one of these life vests in your boat. You already inflated one of the chambers once some time ago, so you know that this bottle is empty. But never minds, there is another one, right?

    You are not rated to operate this boat, but still recklessly operate it in a dangerous reef zone, the hull is breached, you put this life vest and jump. You pull the chord to inflate the other chamber, but it fails. You die and your mother sues me. Know what? Fuck your mom.

    And fuck Asiana. That the pilot made this human-factor mistake is serious enough. That Asiana uses this as a defense is criminal.

    Ok, another point that Asiana makes is not only that the system failed to give them the expected speed protection, but that the plane didn't want them of the deteriorating airspeed with enough time to correct the situation. Let's revise this:

    So, the pilot selected FLTCH, disconnected the AP and retarded the throttle. I don't have this clear, but I will assume that he didn't disconnect the flight director.

    If so, the flight director would have shown command bars on the attitude indicator that, if followed, will have made the plane slow down and then keep Vapp. If the AP had been on, it would have followed these command bars.

    As soon as the speed goes below Vapp, the command bars will show the need to lower the nose to keep the airspeed. Something that the pilot didn't follow. Cue one.

    The plane was last trimmed at 1500ft. From this point down, all and any reduction in airspeed must have been accomplished by the pilot pulling up with increasing yoke travel and increasing force. For any low-time student pilot, the fact that more pull is needed is and must be a clear and unmistakable cue that the speed is going down. Cue two.

    In line with the previously explained increasing pull-up, the airplane was flying with increasing levels of nose-up attitude since, as the speed goes down, the angle of attack must increase to keep the lift. In the last stages of the approach but when there was still time to save the day, the nose-up attitude was way above the normal approach attitude (7° vs the normal 2°), and thios attitude is clearly displayed in 3 attitude indicators (two of them directly in front of the pilots in the PRIMARY FLIGHT display that have the words PRIMARY and FLIGHT in its name for a reason). But, more surprisingly, was also "displayed" in the windshield. Remember this was a visual approach, so the pilot had to be looking outside at least from time to time to see if he was high or low, for example. The CVR even recorded the sound of an electric seat motor, which is strongly suspected was one of the pilots raising the seat to be able to see the approach zone through the windshield with this so nose-up attitude. As said, that you need a too nose-up attitude is a strong cue that you are too slow. Cue 3.

    Several seconds before the crash, when there was still time to correct, they received a 4-chimes warning and an EICAS alert message that said "AIRSPEED LOW". Did they increased the thrust at this point? Nah! The AT will provide!!! Cue 4.

    After all this, the fact the pilot had airspeed indication seems too basic. But there was not one but three airspeed indicators, all correctly showing that the plane was slowing down too much, two of them included a Vapp bug, which is an icon that shows where the airspeed should be so you don't have to say "let's see, the airspeed is 120, it should be 140, oh fuck, I'm 20 kts slow". You just see that the current speed is below the icon and you know you are slow. It's like putting a sticker at the target speed in your car's speedometer. You don't need to "read" the speed. Just tell if the needle is above or below the sticker. Easy, uh? Not only that, but these 2 airspeed indicators that featured the speed bug were, again, directly in front of the pilots in the PRIMARY FLIGHT display that have the words PRIMARY and FLIGHT in its name for a reason. And do you know for how long they showed the speed below the bug until they finally increased thrust? 26 seconds!!!! Who on Earth was the pilot flying the plane during this time? And who was the pilot monitoring? Because holding the speed and monitoring the speed is well within their job requirements, do you know? Cue 5.

    So say again, Asiana?

    "Contributing to this failure were (1) inconsistencies in the aircraft’s automation logic, which led the crew to believe that the autothrottle was maintaining the airspeed set by the crew; and (2) autothrottle logic that unexpectedly disabled the aircraft’s minimum airspeed protection.

    Significant contributing factors to the accident were (1) inadequate warning systems to alert the flight crew that the autothrottle had (i) stopped maintaining the set airspeed and (ii) stopped providing stall protection support; (2) a low speed alerting system that did not provide adequate time for recovery in an approach-to-landing configuration;
    I don't even blame the pilots any longer. This is my final report:

    "The probable cause of this accident was fucking Asiana"

    [/rant]

    --- 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


    • Is anyone gonna read Gabriels post?

      The counter argument is simply this: Across a few million flights could you reasonably expect a couple of humans to brain fart at the same time, line up the Swiss cheese and assume that the speed control is working- just like it's worked thousands of times before...

      ...and, after a long trans-oceanic flight might someone get lax on watching the airspeed...especially when you are making a visual approach on a beautiful evening where most of your time should be spent looking out the window anyway...
      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

      Comment


      • Originally posted by 3WE View Post
        Is anyone gonna read Gabriels post?
        Did you?

        The counter argument is simply this: Across a few million flights could you reasonably expect a couple of humans to brain fart at the same time, line up the Swiss cheese and assume that the speed control is working- just like it's worked thousands of times before...
        Two things:

        Okay, but then the airline blame Boeing.

        Forget the Okay. You should never (let alone a thousands times) have the autothrottle add thrust when the AP is in FLCH mode. It's the equivalent to use the stick pusher to keep you from stalling.

        ...and, after a long trans-oceanic flight might someone get lax on watching the airspeed...especially when you are making a visual approach on a beautiful evening where most of your time should be spent looking out the window anyway...
        Is that sarcastic? The pilot admitted being afraid of visual approaches and that he didn't feel up to the task.

        --- 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 brianw999 View Post
          I would stab a guess that legal action by passengers and relatives of the deceased against the crew as individuals would be a bit of a non starter as they would be simply unable to pay the kind of damages that would be claimed.
          Plaintiffs would therefore be forced to take action against the airline which, given Asiana's latest little gem in trying to blame Boeing would probably result in them throwing their hands up in horror and claiming that they are not responsible as they supplied the required levels of training. The plaintiffs would then be faced with the almost impossible task of proving that the training given simply did not work and that Asiana had failed to adequately audit their training.
          I can see this one going on for a long time.
          a legal principle called respondeat superior makes asiana liable for its employees even if the airline was as pure as jesus' ass on the day he was born. basically, unless the employee was acting outside the scope of his employment, the employer will always be liable. and unfortunately, even grossly negligent flying of the a/c is still within the scope.

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          • Originally posted by elaw View Post
            That... is just plain silly. You've conveniently ignored the fact that without LAWYERS, plaintiffs either cannot, or in any case extremely rarely, file suits. Tell me, how many of the suits related to this accident were filed without the involvement of lawyers? I bet it's approximately 0% of them.

            It's a little like saying that a botched root canal done by a dentist is the fault of the patient for coming to him/her with a toothache...
            you are of course entitled to your opinion.

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            • Gabriel, if i ever take on an aviation case, i'm gonna hire you to testify as at least one of my expert witnesses.

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              • Originally posted by TeeVee View Post
                Gabriel, if i ever take on an aviation case, i'm gonna hire you to testify as at least one of my expert witnesses.
                Why? Do you want me to bore the jury to death?

                --- 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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                • Originally posted by 3WE View Post
                  Is anyone gonna read Gabriels post?
                  I did, a bit long winded haha...but an excellent analysis of how poorly these men flew that airplane, and it makes you wonder how poorly other Asiana crews fly daily in situations we don't hear about.

                  Comment


                  • Originally posted by Gabriel View Post
                    Why? Do you want me to bore the jury to death?
                    nope. i want you to explain "whatever" to them in terms that even a lay person can understand.

                    it was an excellent post

                    Comment


                    • Originally posted by elaw View Post
                      It's a little like saying that a botched root canal done by a dentist is the fault of the patient for coming to him/her with a toothache...
                      i slept on this before deciding to give you a real answer. so here it is.

                      your analogy is a bit imperfect. this is better: you have incredible pain in your jaw you believe is a toothache, so you head to the dentist. he tells you that you need a root canal, so you say, ok, do it. later on you still have pain so you go to a different dentist who tells you that not only is your pain not being caused by a tooth problem, but that you never had a tooth problem to begin with and the root canal was completely unnecessary.

                      here's how it works. a prospective plaintiff walks into a lawyer's office and says he was involved in a plane crash. lawyer immediately gets a hard-on thinking about how much money airlines and plane manufacturers have. he asks you a few questions, decides that boeing must have screwed up because we all know that automation MUST BE PERFECT. so he runs off to the court house and sues boeing for you.

                      what did he do wrong? well, like that dentist, the lawyer had an obligation to properly investigate the claim before filing it. if he had only come to this forum and read gabriel's sagacious soliloquy, he would have know that boeing was not at all liable.

                      now, back to the PLAINTIFFS. many, if not most of the folks that walk into lawyer's offices complaining of some manner of injury are full of shit. were they hurt? i'll bet most were. do they have the type and extent of injury they claim? i'll bet not. but, they are looking at dollars and cents. i'd be willing to bet that if elaw's ass was on the asiana flight and he lived, he would have headed to a lawyer's office as well. why? $$$$$$ plain and simple. he would instantly be thinking,

                      "shit! i nearly died! i'll never be able to fly without being scared out of my mind! SOMEONE HAS TO PAY ME! boeing made the plane, it failed, sue them!"

                      Comment


                      • 3WE:

                        ...and, after a long trans-oceanic flight might someone get lax on watching the airspeed...especially when you are making a visual approach on a beautiful evening where most of your time should be spent looking out the window anyway...

                        Gabe: Is that sarcastic? The pilot admitted being afraid of visual approaches and that he didn't feel up to the task.

                        3WE: No sarcasm.

                        Indeed- that the pilot was afraid of a manual landing really dismisses my question with respect to this incident.

                        However- in general the question remains...is there a reasonable suspicion that over several million landings, a crew might brain-fart and have speed control off, when they think it's on.

                        And- yeah, you should always be glancing at the airspeed...but again, on a beautiful evening after a long flight and a little tunnel vision on the runway ahead as you are aligning so nicely on the TDZE...
                        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                        Comment


                        • Originally posted by 3WE View Post
                          Indeed- that the pilot was afraid of a manual landing really dismisses my question with respect to this incident.

                          However- in general the question remains...is there a reasonable suspicion that over several million landings, a crew might brain-fart and have speed control off, when they think it's on.

                          And- yeah, you should always be glancing at the airspeed...but again, on a beautiful evening after a long flight and a little tunnel vision on the runway ahead as you are aligning so nicely on the TDZE...
                          Ok, in general, it can happen, and it's inexcusable every time.
                          Even in a Piper J3 you closely monitor the airspeed during final. At the very least, you trim for final approach speed and then use the control column as a tactile final-approach-airspeed-deviation indicator.

                          I know you are talking in general, but in this specific case it was not the beautiful approach in a lovely evening where everything was going smoothly and so nicely aligned on the TDZ. They were high and fast and doing all sort of anti-SOP things to try to correct it.

                          And even if it begins as your dreamed approach, the fact that the nose raises to 7° nose up, you are holding the yoke against your balls pulling with quite a bunch of pounds, and all the PAPI lights go red (you can't miss that when you are tunnel-visioning on the TDZ) should all wake you up from that dream.

                          --- 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 TeeVee View Post
                            here's how it works. a prospective plaintiff walks into a lawyer's office and says he was involved in a plane crash. [...] now, back to the PLAINTIFFS. many, if not most of the folks that walk into lawyer's offices [...]
                            Are you sure it's not the other way around in some cases?
                            I've seen lawyers at hospitals giving their business cards to everyone that came crying from a talk with the doctors.

                            In this high-profile cases, I can see big firms that live of commissions on liabilities for damages go out to hunt potential plaintiffs as soon as the event occurs, explaining them how much money they can make and how much they deserve it, and how they are the best lawyer they can contract to have it done. If not, you would not have one firm with 150 victims. The victims will hardly be so organized.

                            "shit! i nearly died! i'll never be able to fly without being scared out of my mind! SOMEONE HAS TO PAY ME! boeing made the plane, it failed, sue them!"
                            I think that the natural reaction of the victim will be to sue the airline, not the airplane manufacturer.
                            I bet that suing Boeing, Rolls Roys, the FAA and what not is the creativity of the lawyer, not the victim.

                            --- 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 TeeVee View Post
                              i slept on this before deciding to give you a real answer. so here it is.

                              your analogy is a bit imperfect. this is better: you have incredible pain in your jaw you believe is a toothache, so you head to the dentist. he tells you that you need a root canal, so you say, ok, do it. later on you still have pain so you go to a different dentist who tells you that not only is your pain not being caused by a tooth problem, but that you never had a tooth problem to begin with and the root canal was completely unnecessary.

                              here's how it works. a prospective plaintiff walks into a lawyer's office and says he was involved in a plane crash. lawyer immediately gets a hard-on thinking about how much money airlines and plane manufacturers have. he asks you a few questions, decides that boeing must have screwed up because we all know that automation MUST BE PERFECT. so he runs off to the court house and sues boeing for you.

                              what did he do wrong? well, like that dentist, the lawyer had an obligation to properly investigate the claim before filing it. if he had only come to this forum and read gabriel's sagacious soliloquy, he would have know that boeing was not at all liable.

                              now, back to the PLAINTIFFS. many, if not most of the folks that walk into lawyer's offices complaining of some manner of injury are full of shit. were they hurt? i'll bet most were. do they have the type and extent of injury they claim? i'll bet not. but, they are looking at dollars and cents. i'd be willing to bet that if elaw's ass was on the asiana flight and he lived, he would have headed to a lawyer's office as well. why? $$$$$$ plain and simple. he would instantly be thinking,

                              "shit! i nearly died! i'll never be able to fly without being scared out of my mind! SOMEONE HAS TO PAY ME! boeing made the plane, it failed, sue them!"
                              Well... and I'll admit this is pretty far off-topic so I'll probably leave it at this... I do agree to an extent with what you say. But I think part of what's in play is a culture that lawyers created... or at least failed to stop.

                              It seems to me "back in the day" - prior to sometime in the 1970's - when a potential plaintiff walked into a lawyer's office and proposed bringing an inappropriate lawsuit (and I understand that term is very subjective), the lawyer would say to the person "you're an idiot - get out of my office". The main motivation probably being for the lawyer to protect his/her professional reputation.

                              Then one day someone walked into a lawyer's office and proposed bringing an inappropriate lawsuit... and the lawyer did not kick the person out of his/her office... he/she filed the suit instead. Once that happened, other lawyers had to follow suit (ha! a pun) to avoid losing business. And so it began.
                              Be alert! America needs more lerts.

                              Eric Law

                              Comment


                              • Originally posted by Gabriel View Post
                                ...They were high and fast and doing all sort of anti-SOP things to try to correct it.

                                And even if it begins as your dreamed approach, the fact that the nose raises to 7° nose up, you are holding the yoke against your balls pulling with quite a bunch of pounds, and all the PAPI lights go red (you can't miss that when you are tunnel-visioning on the TDZ) should all wake you up from that dream.

                                So here's the deal...I can't count the high, fast approaches I've done on MSFS...but I'm aiming at the TDZE and speed is decaying just right to cross the fence VERY close to a proper speed...It's a very fun exercise-and guess what:

                                1) There's this incredibly cool rocker switch by my thumb that I bump to get me more and more nose-up input as the speed decays from 250 kts towards 140 kts. So no column in the crotch like you mention.

                                2) And here's the biggie...I sometimes wind up just a little bit short on speed and height and sometimes even stall into the approach lights. The decaying speed simply sneaks up on me.

                                Sure- beer was sometimes involved and neither the SA (nor the seriousness) was the same as in a real plane...but I compare that to a situation of where you've made thousands of landings and everything is going the right direction...it all LOOKS good, and you are a bit tired...

                                ...sometimes it's that simple.

                                But to restate for clarity- Hui Thieu Lo being afraid to land a plane does derail that comment for this incident.

                                I dunno- maybe he was staring at the VASI and centerline, frozen with fear- too scared to glance at the airspeed but confident that the speed control was doing it's job...

                                I 100% agree that it was crappy flying- but even good pilots sometimes screw up.
                                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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