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That aircraft was being knowingly flown with [edit: a broken sensor]. It was unsafe on takeoff. The final problem that brought the aircraft down - the trim run

That aircraft was being knowingly flown with [edit: a broken sensor]. It was unsafe on takeoff. The final problem that brought the aircraft down - the trim run-away - happens all the time in airliners you've flown in. When the run-away starts, the pilot is supposed to flip two switches to disable the trim system motors. In the Lion Air crash, it is indeed believed that a software bug from the misbehaving sensors started the run-away, but again, handling trim run-aways are something that pilots are supposed to train for and deal with. 737's are even safer here than many airliners, because after you disable the electric trim motors, you have manual wheels in the cockpit that you can rotate to set the trim back to what it should be. Some other airliners in common use don't have these manual trim controls - you have to disable a trim run-away in time, or it's game over.

Someone1234 8y ago
> That aircraft was knowingly flown with multiple broken sensors. It was unsafe on takeoff. You'll need to cite that, since it contrary to any information I can find on the Lion Air accident e.g.: > 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 Your claim that it was "unsafe to takeoff" and had "multiple broken sensors" is pretty remarkable. So I'll definitely need to see a source backing up such remarkable claims.
- teraflop 8y ago
  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.
- danielvf 8y ago
  https://www.google.com/amp/s/amp.theguardian.com/world/2018/nov/28/lion-air-jet-was-not-airworthy-on-flight-before-crash-indonesia-investigators-say https://www.google.com/amp/s/amp.theguardian.com/world/2018/... “Indonesian investigators have said the Lion Air Boeing 737 jet that plunged into the sea, killing 189 people in October, was not airworthy on a flight the day before it crashed. They further found that Lion Air must improve its safety culture and better document repair work on its planes. The flight from Bali to Jakarta on 28 October had experienced similar technical issues to the doomed flight the next day from Jakarta to Pangkal Pinang, said Nurcahyo Utomo, head of Indonesia’s national transport safety committee (KNKT). The pilot of the 28 October flight chose to press on to Jakarta after shutting down the plane’s anti-stall system, Utomo said. “This is the basis of our recommendation to Lion Air. In our view, the plane was not airworthy,” he told a news conference in Jakarta. ... But its investigators said that Lion Air kept putting the plane back into service despite repeatedly failing to fix a problem with the airspeed indicator in the days leading up to the fatal flight.” - So the aircraft spent several days flying with a broken sensor, sometimes without even an attempt at repair. I've removed the multiple sensor part.
  - Someone1234 8y ago
    > “Indonesian investigators have said the Lion Air Boeing 737 jet that plunged into the sea, killing 189 people in October, was not airworthy on a flight the day before it crashed. And was repaired between the two flights as I quoted above. Are you selectively ignoring the information in the very post you replied to? Here's that information again to refresh your memory: > 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 You and the other poster seem to be basing your whole position on time not moving forward in a linear fashion: Failure, repair, flight. In that order. Pointing out the previous day over and over while ignoring what occurred in the interim isn't a real argument.
    - danielvf 8y ago
      Let's say you hear a knocking sound from your car engine. You take it to a mechanic for repairs, and the mechanic says he fixed it. But you still hear the knocking sound. If you repeat this cycle for a few times, when the mechanic says for the Nth time that he fixed the problem, is it actually fixed?
t0mas88 8y ago
> the trim run-away - happens all the time in airliners you've flown in. It doesn't. A trim run-away is a very very serious incident for any pilot. There are procedures to deal with it, and we check trim override in pre-flight checks, but it's absolutely not an everyday thing. > 737's are even safer here than many airliners, because after you disable the electric trim motors, you have manual wheels in the cockpit that you can rotate to set the trim back to what it should be. Some other airliners in common use don't have these manual trim controls - you have to disable a trim run-away in time, or it's game over. This is not true at all either. There are no planes with a single electric trim that you cannot override. The FAA and EASA would refuse to certify those.
- danielvf 8y ago
  Embraer 190? There are no non-electrical trim controls in the cockpit. http://www.smartcockpit.com/docs/Embraer_190-Flight_Controls.pdf http://www.smartcockpit.com/docs/Embraer_190-Flight_Controls... Whereas a 737 has physical cables connected from wheels in the cockpit to the stabilizer jackscrew.
  - t0mas88 8y ago
    I've never flown an E190, but if you Google the basic systems description you'll find that it has two sets of trim controls and on top of that separate override controls. Both circuits are electric, but they are separate systems on separate power busses to ensure you always have control.
    - danielvf 8y ago
      Thanks!

Someone1234 8y ago

> That aircraft was knowingly flown with multiple broken sensors. It was unsafe on takeoff. You'll need to cite that, since it contrary to any information I can find on the Lion Air accident e.g.: > 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 Your claim that it was "unsafe to takeoff" and had "multiple broken sensors" is pretty remarkable. So I'll definitely need to see a source backing up such remarkable claims.

teraflop 8y ago
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.
danielvf 8y ago
https://www.google.com/amp/s/amp.theguardian.com/world/2018/nov/28/lion-air-jet-was-not-airworthy-on-flight-before-crash-indonesia-investigators-say https://www.google.com/amp/s/amp.theguardian.com/world/2018/... “Indonesian investigators have said the Lion Air Boeing 737 jet that plunged into the sea, killing 189 people in October, was not airworthy on a flight the day before it crashed. They further found that Lion Air must improve its safety culture and better document repair work on its planes. The flight from Bali to Jakarta on 28 October had experienced similar technical issues to the doomed flight the next day from Jakarta to Pangkal Pinang, said Nurcahyo Utomo, head of Indonesia’s national transport safety committee (KNKT). The pilot of the 28 October flight chose to press on to Jakarta after shutting down the plane’s anti-stall system, Utomo said. “This is the basis of our recommendation to Lion Air. In our view, the plane was not airworthy,” he told a news conference in Jakarta. ... But its investigators said that Lion Air kept putting the plane back into service despite repeatedly failing to fix a problem with the airspeed indicator in the days leading up to the fatal flight.” - So the aircraft spent several days flying with a broken sensor, sometimes without even an attempt at repair. I've removed the multiple sensor part.
- Someone1234 8y ago
  > “Indonesian investigators have said the Lion Air Boeing 737 jet that plunged into the sea, killing 189 people in October, was not airworthy on a flight the day before it crashed. And was repaired between the two flights as I quoted above. Are you selectively ignoring the information in the very post you replied to? Here's that information again to refresh your memory: > 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 You and the other poster seem to be basing your whole position on time not moving forward in a linear fashion: Failure, repair, flight. In that order. Pointing out the previous day over and over while ignoring what occurred in the interim isn't a real argument.
  - danielvf 8y ago
    Let's say you hear a knocking sound from your car engine. You take it to a mechanic for repairs, and the mechanic says he fixed it. But you still hear the knocking sound. If you repeat this cycle for a few times, when the mechanic says for the Nth time that he fixed the problem, is it actually fixed?

t0mas88 8y ago

> the trim run-away - happens all the time in airliners you've flown in. It doesn't. A trim run-away is a very very serious incident for any pilot. There are procedures to deal with it, and we check trim override in pre-flight checks, but it's absolutely not an everyday thing. > 737's are even safer here than many airliners, because after you disable the electric trim motors, you have manual wheels in the cockpit that you can rotate to set the trim back to what it should be. Some other airliners in common use don't have these manual trim controls - you have to disable a trim run-away in time, or it's game over. This is not true at all either. There are no planes with a single electric trim that you cannot override. The FAA and EASA would refuse to certify those.

danielvf 8y ago
Embraer 190? There are no non-electrical trim controls in the cockpit. http://www.smartcockpit.com/docs/Embraer_190-Flight_Controls.pdf http://www.smartcockpit.com/docs/Embraer_190-Flight_Controls... Whereas a 737 has physical cables connected from wheels in the cockpit to the stabilizer jackscrew.
- t0mas88 8y ago
  I've never flown an E190, but if you Google the basic systems description you'll find that it has two sets of trim controls and on top of that separate override controls. Both circuits are electric, but they are separate systems on separate power busses to ensure you always have control.
  - danielvf 8y ago
    Thanks!