3 ms·

> unclear how speed didn't increase How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware

by arcfour 22d ago

> unclear how speed didn't increase How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware that turbofan engines don't have instant throttle response and need time (up to 8 seconds) to spool up? I think a little more restraint is warranted in something like this if you don't know something that basic. You can actually do the math to work backwards and approximate how much thrust the engines were producing during that time, which was about 15,000 lbf (vs ~120,000 lbf max thrust for a 767-300er) which reduced how quickly they were decelerating by... Maybe a few % or so. But they didn't start accelerating yet. They would have in another second or two, however. I'll agree that they should have gone around far earlier; getting non-spurious GPWS callouts on final because you're trying to dive and find the glideslope is... Crazy, and configuring landing flaps over the numbers is also crazy, and so is landing 10-20kts faster than the highest possible Vref value for the type, and everything else. But that's fairly obvious...

snypher 22d ago
Not having handles where they should be at 1000 callout should have been an instant toga party.
- aaronmdjones 21d ago
  That they passed their minimums and still weren't set up correctly is shocking, yes. How can you commit to landing instead of going around when you're not configured for landing? The more egregious thing to me though is ignoring the GPWS callouts on approach because they were chasing the glideslope. If you can't maintain a stable approach, you need to go around, it's the first thing you learn. You expect this behaviour from a first-timer in the sim, not a commercial cargo pilot.
  - WalterBright 21d ago
    > You expect this behaviour from a first-timer in the sim, not a commercial cargo pilot. I'm curious - are commercial pilots reprimanded for doing a go-round after messing up the approach?
    - aaronmdjones 21d ago
      No, they're reprimanded for continuing. https://skybrary.aero/tutorials/stabilised-approach https://skybrary.aero/tutorials/stabilised-approach
    - arcfour 21d ago
      No. They might have to say why they went around but they can't be punished for it (that's a great way to open yourself up to liability even stripping away all of the human elements). And I can't imagine any reason that an airline would truly care since they don't want their planes crashing so they don't want to discourage pilots from going around if they need to do so. The delay incurred is usually fairly small anyways, maybe 20-30 minutes. However I will say that the majority of unstable approaches (97%!!) do continue to landing: https://flightsafety.org/wp-content/uploads/2017/03/Go-around-study_final.pdf https://flightsafety.org/wp-content/uploads/2017/03/Go-aroun... ...but I think that most of these unstable approaches are likely marginally unstable and only in one dimension. This landing was so far outside the realm of normal it's actually mind boggling that it actually happened. Pilots are trained to immediately go around without questioning it if many of the things that happened on this flight occur (such as not being in landing configuration well before touching down!)
overfeed 22d ago
> How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware that ... This is par for the course for HN; smart people applying first-principle thinking on unfamiliar domains for about a minute, which confirms the biases of other outsiders who vote the plausible, but not-quite-right comments to the top.
- stouset 21d ago
  This sounds about right to me, so I upvoted.
- stackghost 21d ago
  HN is particularly notorious for armchair aviation experts. I am an aerospace engineer having worked in airworthiness & certification as well as maintenance/repair/overhaul on multiple different aircraft types both fixed and rotary. I mention this only to establish my bona fides as someone who knows their shit: The comments here during the 737 MAX MCAS thing were fucking wild. So many randoms spitting out confidently incorrect nonsense.
  - sen 21d ago
    That’s all forums in a nut shell. Any time you read about something you’re not personally familiar with it’s “look at all these people who know what they’re talking about… “, as soon as it’s something you are personally familiar with it’s “wtf are these people on about?!”
    - implements 21d ago
      “Gell-Mann Amnesia“ - usually applied to media when experts scoff at stories they know to be sometimes woefully inaccurate but still accept all the other pages as gospel. Coined by Michael Crichton (the famous author).
  - oefrha 21d ago
    HN is notorious for armchair <insert-topic> experts for <insert-topic> you actually know, outside of software, computing/computing-adjacent electronic hardware and startups. “Fucking wild” “confidently incorrect nonsense” is likely the norm on most fringe topics, judging by the few I know about.
eh_why_not 21d ago
> How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware that turbofan engines don't have instant throttle response and need time (up to 8 seconds) to spool up? I think a little more restraint is warranted in something like this if you don't know something that basic. I'm a pilot, and I don't fly turbofans/jets. Not claiming any "authority", but qualified to comment... It's not "something that basic" unless you fly in that category, there's a lot more to aviation experience than knowing a fact about an engine you don't use. (But hey, congrats to you that you know it!) > I think a little more restraint is warranted in something like this.. More restraint than saying "unclear <i.e. to me> why ...", an exact statement about what I didn't know, which harms no one and led to several informative explanations by people who know (most of them in good spirit)? This is what good conversation is about. ... Anyway, the point I was making holds and is this: Orthogonal to whether they could/should have gone around at that point, and given that they stayed on the ground after all, it may turn out that that 4 seconds of indecision (instead of pure deceleration) may have directly contributed to the fatalities at the end of the crash.
AdamN 21d ago
We're not jurors or NTSB investigators - this is just a public messageboard on a tech-focused platform. It's totally fine to speculate and wonder here ... and to be corrected respectfully.
- arcfour 21d ago
  Was anything I said disrespectful? It is not intended to be, but it may read as somewhat stern; that's more because speculating without having the fundamentals down is not what I expect from HN. The knowledge in question isn't arcane or a secret.

by arcfour 22d ago

snypher 22d ago

Not having handles where they should be at 1000 callout should have been an instant toga party.

aaronmdjones 21d ago
That they passed their minimums and still weren't set up correctly is shocking, yes. How can you commit to landing instead of going around when you're not configured for landing? The more egregious thing to me though is ignoring the GPWS callouts on approach because they were chasing the glideslope. If you can't maintain a stable approach, you need to go around, it's the first thing you learn. You expect this behaviour from a first-timer in the sim, not a commercial cargo pilot.
- WalterBright 21d ago
  > You expect this behaviour from a first-timer in the sim, not a commercial cargo pilot. I'm curious - are commercial pilots reprimanded for doing a go-round after messing up the approach?
  - aaronmdjones 21d ago
    No, they're reprimanded for continuing. https://skybrary.aero/tutorials/stabilised-approach https://skybrary.aero/tutorials/stabilised-approach
  - arcfour 21d ago
    No. They might have to say why they went around but they can't be punished for it (that's a great way to open yourself up to liability even stripping away all of the human elements). And I can't imagine any reason that an airline would truly care since they don't want their planes crashing so they don't want to discourage pilots from going around if they need to do so. The delay incurred is usually fairly small anyways, maybe 20-30 minutes. However I will say that the majority of unstable approaches (97%!!) do continue to landing: https://flightsafety.org/wp-content/uploads/2017/03/Go-around-study_final.pdf https://flightsafety.org/wp-content/uploads/2017/03/Go-aroun... ...but I think that most of these unstable approaches are likely marginally unstable and only in one dimension. This landing was so far outside the realm of normal it's actually mind boggling that it actually happened. Pilots are trained to immediately go around without questioning it if many of the things that happened on this flight occur (such as not being in landing configuration well before touching down!)

overfeed 22d ago

> How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware that ... This is par for the course for HN; smart people applying first-principle thinking on unfamiliar domains for about a minute, which confirms the biases of other outsiders who vote the plausible, but not-quite-right comments to the top.

stouset 21d ago
This sounds about right to me, so I upvoted.
stackghost 21d ago
HN is particularly notorious for armchair aviation experts. I am an aerospace engineer having worked in airworthiness & certification as well as maintenance/repair/overhaul on multiple different aircraft types both fixed and rotary. I mention this only to establish my bona fides as someone who knows their shit: The comments here during the 737 MAX MCAS thing were fucking wild. So many randoms spitting out confidently incorrect nonsense.
- sen 21d ago
  That’s all forums in a nut shell. Any time you read about something you’re not personally familiar with it’s “look at all these people who know what they’re talking about… “, as soon as it’s something you are personally familiar with it’s “wtf are these people on about?!”
  - implements 21d ago
    “Gell-Mann Amnesia“ - usually applied to media when experts scoff at stories they know to be sometimes woefully inaccurate but still accept all the other pages as gospel. Coined by Michael Crichton (the famous author).
- oefrha 21d ago
  HN is notorious for armchair <insert-topic> experts for <insert-topic> you actually know, outside of software, computing/computing-adjacent electronic hardware and startups. “Fucking wild” “confidently incorrect nonsense” is likely the norm on most fringe topics, judging by the few I know about.

eh_why_not 21d ago

> How can you comment as if you are knowledgeable enough about aviation to speak on this with authority, but you aren't aware that turbofan engines don't have instant throttle response and need time (up to 8 seconds) to spool up? I think a little more restraint is warranted in something like this if you don't know something that basic. I'm a pilot, and I don't fly turbofans/jets. Not claiming any "authority", but qualified to comment... It's not "something that basic" unless you fly in that category, there's a lot more to aviation experience than knowing a fact about an engine you don't use. (But hey, congrats to you that you know it!) > I think a little more restraint is warranted in something like this.. More restraint than saying "unclear <i.e. to me> why ...", an exact statement about what I didn't know, which harms no one and led to several informative explanations by people who know (most of them in good spirit)? This is what good conversation is about. ... Anyway, the point I was making holds and is this: Orthogonal to whether they could/should have gone around at that point, and given that they stayed on the ground after all, it may turn out that that 4 seconds of indecision (instead of pure deceleration) may have directly contributed to the fatalities at the end of the crash.

AdamN 21d ago

We're not jurors or NTSB investigators - this is just a public messageboard on a tech-focused platform. It's totally fine to speculate and wonder here ... and to be corrected respectfully.

arcfour 21d ago
Was anything I said disrespectful? It is not intended to be, but it may read as somewhat stern; that's more because speculating without having the fundamentals down is not what I expect from HN. The knowledge in question isn't arcane or a secret.