3 ms·

> MCAS is specifically designed for an edge case Source? That's the first I've heard that it's only for edge cases.

dsfyu404ed 8y ago
If the pilot, who hopefully has thicker skin than people on the internet, moves the buttons and levers properly MCAS should never have to do anything. It's only supposed to actually do anything when you let the nose pitch up a little too much (which the system will detect using the AoA sensors)[0]. It's like automatic braking in a new car, if you drive the way you're "expected to" you shouldn't be activating it often. [0] https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/ https://theaircurrent.com/aviation-safety/what-is-the-boeing...
- Rooster61 8y ago
  Again, please post a source backing this claim up. And it would be appreciated if the folks that died commanding this flight were not referred to as "meat bags".
  - dsfyu404ed 8y ago
    Edited the original.
- Gibbon1 8y ago
  > when you let the nose pitch up a little too much Or flying into windshear changes the angle of attack on you.
pdonis 8y ago
> That's the first I've heard that it's only for edge cases. It's only supposed to activate in a specific edge case (high angle of attack, manual flight, no flaps, low airspeed). That's been discussed plenty online (including previous threads here at HN). But that assumes that the angle of attack sensors are accurate. If the AoA sensors are inaccurate, as they were on this flight (more specifically the left one), MCAS can activate when it's not supposed to. That's what happened here.
- cjbprime 8y ago
  I don't agree with "low airspeed". You can exceed critical AoA (and therefore stall) at any airspeed.
  - pdonis 8y ago
    > You can exceed critical AoA (and therefore stall) at any airspeed. I wasn't talking about at what airspeeds a stall is possible. I was talking about at what airspeeds MCAS is designed to activate (assuming correct AoA sensor input).

If the pilot, who hopefully has thicker skin than people on the internet, moves the buttons and levers properly MCAS should never have to do anything. It's only supposed to actually do anything when you let the nose pitch up a little too much (which the system will detect using the AoA sensors)[0]. It's like automatic braking in a new car, if you drive the way you're "expected to" you shouldn't be activating it often. [0] https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/ https://theaircurrent.com/aviation-safety/what-is-the-boeing...

Rooster61 8y ago
Again, please post a source backing this claim up. And it would be appreciated if the folks that died commanding this flight were not referred to as "meat bags".
- dsfyu404ed 8y ago
  Edited the original.
Gibbon1 8y ago
> when you let the nose pitch up a little too much Or flying into windshear changes the angle of attack on you.

pdonis 8y ago

> That's the first I've heard that it's only for edge cases. It's only supposed to activate in a specific edge case (high angle of attack, manual flight, no flaps, low airspeed). That's been discussed plenty online (including previous threads here at HN). But that assumes that the angle of attack sensors are accurate. If the AoA sensors are inaccurate, as they were on this flight (more specifically the left one), MCAS can activate when it's not supposed to. That's what happened here.

cjbprime 8y ago
I don't agree with "low airspeed". You can exceed critical AoA (and therefore stall) at any airspeed.
- pdonis 8y ago
  > You can exceed critical AoA (and therefore stall) at any airspeed. I wasn't talking about at what airspeeds a stall is possible. I was talking about at what airspeeds MCAS is designed to activate (assuming correct AoA sensor input).