7 ms·

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

thefounder 7y ago
How is that? Even if its nose goes down after take off? That's something for sure.
Someone1234 7y 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 7y 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 7y 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 7y 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.
- fulafel 7y ago
  Flying at all, given currently unfolding climate catastrophe, does reflect tolerance (or even disregard) for putting life at risk. Actually this change in the risk appetite of the average future air travelers might have impact on how safety is emphasized in the future.

How is that? Even if its nose goes down after take off? That's something for sure.

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 7y 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 7y 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 7y 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.
fulafel 7y ago
Flying at all, given currently unfolding climate catastrophe, does reflect tolerance (or even disregard) for putting life at risk. Actually this change in the risk appetite of the average future air travelers might have impact on how safety is emphasized in the future.