4 ms·

From the same Wikipedia article that was just linked: > "The aircraft suffered an airspeed indicator problem for its last four flights, including the flight to

From the same Wikipedia article that was just linked: > "The aircraft suffered an airspeed indicator problem for its last four flights, including the flight to Denpasar. Thinking that it would fix the problem, the engineers in Bali then replaced one of the aircraft's AoA sensors, but the problem persisted on the penultimate flight [...] [the crew] recorded a twenty-degree difference between the readings of the left AoA sensor and the right sensor." > "On 28 November, Indonesia investigators said the Lion Air jet was not airworthy on flight before crash."

Someone1234 8y ago
Those are prior flights. The aircraft was fully repaired: > The chief executive officer of Lion Air, Edward Sirait, said the aircraft had a "technical issue" on Sunday night, but this had been addressed in accordance with maintenance manuals issued by the manufacturer. Engineers had declared that the aircraft was ready for takeoff on the morning of the accident So you still haven't supported your extraordinary claim that the aircraft was: > unsafe on takeoff. In fact we know it was safe on takeoff.
- laken 8y ago
  Quoting from the same comment you just replied to: > "On 28 November, Indonesia investigators said the Lion Air jet was not airworthy on flight before crash." "not airworthy" means that it was unsafe.
  - detaro 8y ago
    on flight before the crash. After which it was repaired, and sent on the fatal flight.
    - DuskStar 8y ago
      It was also repaired before the previous flight. It goes like this: several flights report problem maintenance "fixes" the problem next flight reports that another, worse problem has appeared - bad enough that regulators have now said that the plane was "not airworthy" during this flight maintenance "fixes" the problem final flight impacts ocean at high speed Your assertion is that since maintenance cleared the plane after the second fix, the plane must have been fine. To that, I point to the previous time maintenance cleared the plane, when it was demonstrably not fine.
      - detaro 8y ago
        No, my claim merely was that the quote does not make the claim about the specific flight (although I didn't word it quite clearly). The findings about bad maintenance culture certainly suggest that the plane wasn't fixed properly.
  - Someone1234 8y ago
    Indeed, in a completely different flight than the one we're discussing.
- FabHK 8y ago
  > we know it was safe on takeoff Or rather, as airworthy as any other MAX flying around. Not sure why you're being downvoted, as I haven't seen any evidence linked contradicting what you said.
inferiorhuman 8y ago
Right, there were repeated problems with the angle of attack sensor. If I had to guess the sensor itself is and was just fine and the problem lay elsewhere in the pipeline. More important though is that the 737 MAX differs wildly from earlier 737s in how much it relies on the AoA data. Mechanics and pilots not experienced with the MAX were probably operating under the (false) assumption that a bad alpha vane wouldn't be the end of the world. In fact displays indicating the angle of attack and warnings about disparity between the alpha vanes is an optional feature on the 737. It's considered that unimportant. The key differences from earlier 737s are that the MAX uses the AoA data to calculate airspeed and that the MAX may use a single AoA input to try to kill you. I believe the former was disclosed, but considered how short the differences training is may have been easily overlooked. The latter, of course, was not disclosed until the crash.

Someone1234 8y ago

Those are prior flights. The aircraft was fully repaired: > The chief executive officer of Lion Air, Edward Sirait, said the aircraft had a "technical issue" on Sunday night, but this had been addressed in accordance with maintenance manuals issued by the manufacturer. Engineers had declared that the aircraft was ready for takeoff on the morning of the accident So you still haven't supported your extraordinary claim that the aircraft was: > unsafe on takeoff. In fact we know it was safe on takeoff.

laken 8y ago
Quoting from the same comment you just replied to: > "On 28 November, Indonesia investigators said the Lion Air jet was not airworthy on flight before crash." "not airworthy" means that it was unsafe.
- detaro 8y ago
  on flight before the crash. After which it was repaired, and sent on the fatal flight.
  - DuskStar 8y ago
    It was also repaired before the previous flight. It goes like this: several flights report problem maintenance "fixes" the problem next flight reports that another, worse problem has appeared - bad enough that regulators have now said that the plane was "not airworthy" during this flight maintenance "fixes" the problem final flight impacts ocean at high speed Your assertion is that since maintenance cleared the plane after the second fix, the plane must have been fine. To that, I point to the previous time maintenance cleared the plane, when it was demonstrably not fine.
    - detaro 8y ago
      No, my claim merely was that the quote does not make the claim about the specific flight (although I didn't word it quite clearly). The findings about bad maintenance culture certainly suggest that the plane wasn't fixed properly.
- Someone1234 8y ago
  Indeed, in a completely different flight than the one we're discussing.
FabHK 8y ago
> we know it was safe on takeoff Or rather, as airworthy as any other MAX flying around. Not sure why you're being downvoted, as I haven't seen any evidence linked contradicting what you said.

inferiorhuman 8y ago

Right, there were repeated problems with the angle of attack sensor. If I had to guess the sensor itself is and was just fine and the problem lay elsewhere in the pipeline. More important though is that the 737 MAX differs wildly from earlier 737s in how much it relies on the AoA data. Mechanics and pilots not experienced with the MAX were probably operating under the (false) assumption that a bad alpha vane wouldn't be the end of the world. In fact displays indicating the angle of attack and warnings about disparity between the alpha vanes is an optional feature on the 737. It's considered that unimportant. The key differences from earlier 737s are that the MAX uses the AoA data to calculate airspeed and that the MAX may use a single AoA input to try to kill you. I believe the former was disclosed, but considered how short the differences training is may have been easily overlooked. The latter, of course, was not disclosed until the crash.