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That's commentary. We can reasonably speculate they were looking at warnings and the flight log, autopilot is only one part of the flight director and as autopi

That's commentary. We can reasonably speculate they were looking at warnings and the flight log, autopilot is only one part of the flight director and as autopilot was never turned back on, pointing at it seems odd.

inferiorhuman 7y ago
That's commentary. Changing settings in the flight director is very much an action (not mere commentary). Plus it's a good distraction from flying the plane — especially while the overspeed alarm is going off.
- orwin 7y ago
  Maybe, just maybe, when you're in a plane that does not respond to your commands, you want to have a look at the most likely possibility: the autopilot did not disengage, or the autopilot malfunctionned and prevents you to get full control of the airplane. IF hte pilots knew about MCAS, they would likely have checked that instead, but they did not. Most pilots are rationnal and pretty smart people. Implying that two of them are stupid enough to "play" with the autopilot in this situation is pretty insulting. This kind of reactions are interesting though. I might tour facebook, twitter and reddit to see if it's widespread.
- cmurf 7y ago
  Overspeed is the result of the mistrim. They were in fact flying the plane, the significant back pressure they used to fight the mistrim makes that clear. On what basis do they anticipate 4 seconds after two successful nose up trim using yoke toggle switches (manually initiated, electric motor turns jackscrew) that MCAS will cause a 40 degree nose down within seconds? Nothing. There's no basis for expecting such madness. The emergency AD following LNI610 doesn't at all account for significant mistrim, the possibility of heavy jackscrew loading forces that could prevent manual (handcrank) retrim, and the necessity of setting stab trim switches back to normal to solve the mistrim. It's realy vile to me that this whole mistrim scenario was not thoroughly explored by the FAA and NTSB (independently of each other) in 737 MAX capable simulators following Lion Air 610. Very clearly the emergency AD was still inadequate months after Lion Air 610. Could ET302 have been prevented? Perhaps, but not based on the then published AD.
  - inferiorhuman 7y ago
    Overspeed is the result of the mistrim No, it wasn't. Overspeed was because the pilots basically firewalled the throttles and never once touched them. Look at the Lion Air flights, they never came close to those sorts of speeds.
    - cmurf 7y ago
      If I'm trimmed for level flight and go to 100% power, I will not overspeed. Initial airspeed increases, the plane starts to climb, airspeed decreases, and fairly quickly without any other inputs the airspeed will return to level flight airspeed, but I'll be in a climb. It's basic aerodynmics. Primary flight students are taught this, and in more advanced training it's given a name: positive static stability. All FAR 23 and FAR 25 certified airplanes have this behavior. In the case of ET302, the power settings were completely normal for the phase of flight they were in. What was abnormal was the trim. If the trim were normal, they would have had a normal climb and normal climb speed. On what basis would or should the pilots have made a power reduction? In the case of LNI034 and LNI610, you're determining speed how? Do you have a page reference? Are you even able to estimate percent Vno? What I see for LNI610 is normal takeoff power, and just before midway through the flight a power reduction. Airspeed isn't affected. And how are you comparing the stabilizer trim setting value between LNI610 and ET302?
      - inferiorhuman 7y ago
        In the case of ET302, the power settings were completely normal for the phase of flight they were in. N1 was nearly at 100% for most of the flight. ET302 had an unreliable airspeed situation, yeah? My understanding is that the memory items for this on the 737 involves setting the throttles to well less than 100% (closer to 80-85% is what I've seen). Honestly I thought climb thrust was around 80% as well. On what basis would or should the pilots have made a power reduction? Both the overspeed clackers were going off for much of the flight (granted so was one of the stick shakers — at the same time). In the case of LNI034 and LNI610, you're determining speed how? The initial leak of the preliminary report included units with the graphs. https://ngamotu.nz/images/20181122-jt610-knkt.pdf https://ngamotu.nz/images/20181122-jt610-knkt.pdf

inferiorhuman 7y ago

That's commentary. Changing settings in the flight director is very much an action (not mere commentary). Plus it's a good distraction from flying the plane — especially while the overspeed alarm is going off.

orwin 7y ago
Maybe, just maybe, when you're in a plane that does not respond to your commands, you want to have a look at the most likely possibility: the autopilot did not disengage, or the autopilot malfunctionned and prevents you to get full control of the airplane. IF hte pilots knew about MCAS, they would likely have checked that instead, but they did not. Most pilots are rationnal and pretty smart people. Implying that two of them are stupid enough to "play" with the autopilot in this situation is pretty insulting. This kind of reactions are interesting though. I might tour facebook, twitter and reddit to see if it's widespread.
cmurf 7y ago
Overspeed is the result of the mistrim. They were in fact flying the plane, the significant back pressure they used to fight the mistrim makes that clear. On what basis do they anticipate 4 seconds after two successful nose up trim using yoke toggle switches (manually initiated, electric motor turns jackscrew) that MCAS will cause a 40 degree nose down within seconds? Nothing. There's no basis for expecting such madness. The emergency AD following LNI610 doesn't at all account for significant mistrim, the possibility of heavy jackscrew loading forces that could prevent manual (handcrank) retrim, and the necessity of setting stab trim switches back to normal to solve the mistrim. It's realy vile to me that this whole mistrim scenario was not thoroughly explored by the FAA and NTSB (independently of each other) in 737 MAX capable simulators following Lion Air 610. Very clearly the emergency AD was still inadequate months after Lion Air 610. Could ET302 have been prevented? Perhaps, but not based on the then published AD.
- inferiorhuman 7y ago
  Overspeed is the result of the mistrim No, it wasn't. Overspeed was because the pilots basically firewalled the throttles and never once touched them. Look at the Lion Air flights, they never came close to those sorts of speeds.
  - cmurf 7y ago
    If I'm trimmed for level flight and go to 100% power, I will not overspeed. Initial airspeed increases, the plane starts to climb, airspeed decreases, and fairly quickly without any other inputs the airspeed will return to level flight airspeed, but I'll be in a climb. It's basic aerodynmics. Primary flight students are taught this, and in more advanced training it's given a name: positive static stability. All FAR 23 and FAR 25 certified airplanes have this behavior. In the case of ET302, the power settings were completely normal for the phase of flight they were in. What was abnormal was the trim. If the trim were normal, they would have had a normal climb and normal climb speed. On what basis would or should the pilots have made a power reduction? In the case of LNI034 and LNI610, you're determining speed how? Do you have a page reference? Are you even able to estimate percent Vno? What I see for LNI610 is normal takeoff power, and just before midway through the flight a power reduction. Airspeed isn't affected. And how are you comparing the stabilizer trim setting value between LNI610 and ET302?
    - inferiorhuman 7y ago
      In the case of ET302, the power settings were completely normal for the phase of flight they were in. N1 was nearly at 100% for most of the flight. ET302 had an unreliable airspeed situation, yeah? My understanding is that the memory items for this on the 737 involves setting the throttles to well less than 100% (closer to 80-85% is what I've seen). Honestly I thought climb thrust was around 80% as well. On what basis would or should the pilots have made a power reduction? Both the overspeed clackers were going off for much of the flight (granted so was one of the stick shakers — at the same time). In the case of LNI034 and LNI610, you're determining speed how? The initial leak of the preliminary report included units with the graphs. https://ngamotu.nz/images/20181122-jt610-knkt.pdf https://ngamotu.nz/images/20181122-jt610-knkt.pdf