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Would you still fly with Boeing Max after all this? I understand that the "issue" can be fixed with software but it looks like a hardware/design issue in the fi

Would you still fly with Boeing Max after all this? I understand that the "issue" can be fixed with software but it looks like a hardware/design issue in the first place. If your highest priority is safety the software should be used only when the hardware fails not to support a flawed design.

Innominate 8y ago
I would be perfectly comfortable flying on the 737 Max right now even without the software fixes.
- thefounder 8y ago
  How is that? Even if its nose goes down after take off? That's something for sure.
- Someone1234 8y ago
  That's an irrational position. After the Ethiopian Airlines initial report was released pilots were discussing refusing to fly them even for ferry flights (i.e. no passengers). The Ethiopian airlines crew followed Boeing's post-Lion Air safety bulletin and still crashed. There's no safe way to operate a 737 Max in its current state. The hypothetical recovery techniques (e.g. point nose down to release pressure on the horizontal stabilizer) only work at high altitude, which is notable if Ethiopian airline's AOA sensor was damaged by a bird strike right after take-off. Nobody who understands the current state of this investigation should be saying they'd be comfortable on a 737 Max without changes. The "pilot training" narrative isn't just dead, but dead, buried, with a tomb stone. Sure, pilots should have received training on MCAS existing, but MCAS was commanding trim changes that aren't easily recoverable under any circumstances and certainly not if you follow procedure and disable electronic trim. Nobody should fly on the 737 Max until an update completed, I'd go so far as to suggest that the US/EU should ban ferry flights.
  - Zak 8y ago
    > The hypothetical recovery techniques (e.g. point nose down to release pressure on the horizontal stabilizer) only work at high altitude That's not quite right. Manually operating the motorized trim as soon as unwanted nose-down trim is detected prior to disabling it with the cutout switches appears to be a viable means of recovery. It's also an undocumented, timing-sensitive procedure in a critical phase of flight, which is not anything resembling what airline pilots want from their planes.
    - Someone1234 8y ago
      > Manually operating the motorized trim as soon as unwanted nose-down trim is detected prior to disabling it with the cutout switches appears to be a viable means of recovery. That's what the Lion Air crew did. They died. The Ethiopian Airlines crew followed Boeing's safety bulletin. They also died. But I do take your point, which may prove to be correct. It is hypothetically possible to electronically trim against MCAS then immediately cut out the electronic trim system before MCAS has a chance to re-initiate (5 secs after last trim command). Then you mechanically trim for the remainder of the flight, which should be possible without too much pressure on the horizontal stabilizer. It is crazy to think that that may ultimately be the life saving procedure here, given its complexity/nuance. Particularly for a largely undocumented (for flight crew) system.
      - Zak 8y ago
        The information I'm aware of so far is that the Lion Air flight crew did repeatedly attempt to adjust the trim, but it's not known if they used the cutout switches. A previous flight with the same aircraft did experience runaway trim,and the cutouts were used before the problem became unrecoverable. I find the design of this system shockingly ill-considered. At the very least, it should require input from both sensors and not activate if the sensors disagree. It seems to me a better system would be to automatically add some nose-down trim if the pilot applies full forward pressure on the stick since the primary underlying concern is insufficient elevator authority in certain impending stall conditions for that standard pilot response to be effective.
  - 8y ago
hodgesrm 8y ago
Sure, assuming it's just MCAS. The B737 program has had previous problems most notably uncommanded rudder movement that caused two US crashes in the 1990s with loss of all on board. [1] From what's visible so far in the investigations Boeing (a) botched the MCAS implementation and (b) failed to train pilots on differences between the Max and previous models. Cure those two and the problem seems to be solved. [1] https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues
- thefounder 8y ago
  As far as I understand without MCAS software the aircraft is impossible to fly manually. I'm not sure I'm comfortable with that. Like turning off self driving just to find out that the car still changes direction by itself to compensate for a twisted wheel.
  - Obi_Juan_Kenobi 8y ago
    > As far as I understand without MCAS software the aircraft is impossible to fly manually. Why does anyone think this? The MCAS system rarely engages. The issue is simply to make the stick behavior similar to the older 737s at high AoA. For an older 737, when you're pitching way up, you really have to pull on the yoke to keep that high AoA. The plane naturally wants to return to a neutral AoA, so you have to fight it. With the new design, the engine position keeps the plane from wanting to return to the neutral AoA, at least to the degree it did before. Hence, the 'stick feel' at high AoA is lighter. You don't get the same tactile feedback about being near a stall. (you still have the stick shaker) The MCAS is simply there to bring back that resistance to extreme AoA, and thus make it less likely to accidentally stall. MCAS isn't even active with flaps down (i.e. around takeoff and landing) so can't possibly affect those aspects of flight. It's a questionable design for a number of reasons, but it's not at all necessary for flight, let alone 'basically impossible' without it.
    - cavisne 8y ago
      I think the point is more you have to go all the way to manual trim to disable MCAS. For Lion Air, the pilots didnt run (or even recall) the checklist so didn't disable MCAS. However Ethiopian appears much worse, pilots did run the checklist, had some success with MCAS turned off but couldn't operate the manual trim (unclear why). They then made the fatal decision to turn back on electric trim (and MCAS with it) and MCAS almost immediately nosed them down into an unrecoverable state.

Innominate 8y ago

I would be perfectly comfortable flying on the 737 Max right now even without the software fixes.

thefounder 8y ago
How is that? Even if its nose goes down after take off? That's something for sure.
Someone1234 8y ago
That's an irrational position. After the Ethiopian Airlines initial report was released pilots were discussing refusing to fly them even for ferry flights (i.e. no passengers). The Ethiopian airlines crew followed Boeing's post-Lion Air safety bulletin and still crashed. There's no safe way to operate a 737 Max in its current state. The hypothetical recovery techniques (e.g. point nose down to release pressure on the horizontal stabilizer) only work at high altitude, which is notable if Ethiopian airline's AOA sensor was damaged by a bird strike right after take-off. Nobody who understands the current state of this investigation should be saying they'd be comfortable on a 737 Max without changes. The "pilot training" narrative isn't just dead, but dead, buried, with a tomb stone. Sure, pilots should have received training on MCAS existing, but MCAS was commanding trim changes that aren't easily recoverable under any circumstances and certainly not if you follow procedure and disable electronic trim. Nobody should fly on the 737 Max until an update completed, I'd go so far as to suggest that the US/EU should ban ferry flights.
- Zak 8y ago
  > The hypothetical recovery techniques (e.g. point nose down to release pressure on the horizontal stabilizer) only work at high altitude That's not quite right. Manually operating the motorized trim as soon as unwanted nose-down trim is detected prior to disabling it with the cutout switches appears to be a viable means of recovery. It's also an undocumented, timing-sensitive procedure in a critical phase of flight, which is not anything resembling what airline pilots want from their planes.
  - Someone1234 8y ago
    > Manually operating the motorized trim as soon as unwanted nose-down trim is detected prior to disabling it with the cutout switches appears to be a viable means of recovery. That's what the Lion Air crew did. They died. The Ethiopian Airlines crew followed Boeing's safety bulletin. They also died. But I do take your point, which may prove to be correct. It is hypothetically possible to electronically trim against MCAS then immediately cut out the electronic trim system before MCAS has a chance to re-initiate (5 secs after last trim command). Then you mechanically trim for the remainder of the flight, which should be possible without too much pressure on the horizontal stabilizer. It is crazy to think that that may ultimately be the life saving procedure here, given its complexity/nuance. Particularly for a largely undocumented (for flight crew) system.
    - Zak 8y ago
      The information I'm aware of so far is that the Lion Air flight crew did repeatedly attempt to adjust the trim, but it's not known if they used the cutout switches. A previous flight with the same aircraft did experience runaway trim,and the cutouts were used before the problem became unrecoverable. I find the design of this system shockingly ill-considered. At the very least, it should require input from both sensors and not activate if the sensors disagree. It seems to me a better system would be to automatically add some nose-down trim if the pilot applies full forward pressure on the stick since the primary underlying concern is insufficient elevator authority in certain impending stall conditions for that standard pilot response to be effective.
- 8y ago

hodgesrm 8y ago

Sure, assuming it's just MCAS. The B737 program has had previous problems most notably uncommanded rudder movement that caused two US crashes in the 1990s with loss of all on board. [1] From what's visible so far in the investigations Boeing (a) botched the MCAS implementation and (b) failed to train pilots on differences between the Max and previous models. Cure those two and the problem seems to be solved. [1] https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues

thefounder 8y ago
As far as I understand without MCAS software the aircraft is impossible to fly manually. I'm not sure I'm comfortable with that. Like turning off self driving just to find out that the car still changes direction by itself to compensate for a twisted wheel.
- Obi_Juan_Kenobi 8y ago
  > As far as I understand without MCAS software the aircraft is impossible to fly manually. Why does anyone think this? The MCAS system rarely engages. The issue is simply to make the stick behavior similar to the older 737s at high AoA. For an older 737, when you're pitching way up, you really have to pull on the yoke to keep that high AoA. The plane naturally wants to return to a neutral AoA, so you have to fight it. With the new design, the engine position keeps the plane from wanting to return to the neutral AoA, at least to the degree it did before. Hence, the 'stick feel' at high AoA is lighter. You don't get the same tactile feedback about being near a stall. (you still have the stick shaker) The MCAS is simply there to bring back that resistance to extreme AoA, and thus make it less likely to accidentally stall. MCAS isn't even active with flaps down (i.e. around takeoff and landing) so can't possibly affect those aspects of flight. It's a questionable design for a number of reasons, but it's not at all necessary for flight, let alone 'basically impossible' without it.
  - cavisne 8y ago
    I think the point is more you have to go all the way to manual trim to disable MCAS. For Lion Air, the pilots didnt run (or even recall) the checklist so didn't disable MCAS. However Ethiopian appears much worse, pilots did run the checklist, had some success with MCAS turned off but couldn't operate the manual trim (unclear why). They then made the fatal decision to turn back on electric trim (and MCAS with it) and MCAS almost immediately nosed them down into an unrecoverable state.