Comment by arcfour
11 hours 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...
> 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.
This is par for the course for HN; smart people failing to interpret a comment in a charitable light, preferring instead to author a condescending reply in an apparent effort to score imaginary points at the expense of intellectually stimulating conversation.
Turbofans being slow to spool up is jets 101.
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>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.
You get what you incentivize. The point of the number in the top right is to incentivize. This kind of contribution is what this place is built for.
This sounds about right to me, so I upvoted.
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.
> The comments here during the 737 MAX MCAS thing were fucking wild. So many randoms spitting out confidently incorrect nonsense.
Maybe that helps explain some of the fraction of HN that loves LLMs: they found their soulmates.
The most ridiculous one was a poster who claimed that MCAS would run the trim at double the rate of the trim switches.
The trim motors only have 2 speeds - on and off.
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.
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?!”
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I've worked on several engine families engine certification, I can't read threads about aviation on HN because my brain hurts too much from people who know nothing posting like they are experts nonstop.
It actually causes me stress because a) I need to prevent myself from posting corrections and b) from knowing that these people are everywhere and are posting fud about trains or something
Lots of armchair experts incorrecting each other
HN = A bunch of weirdly aggressive nerds who fail to explore nuance living in the same prison cell.
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.
Not having handles where they should be at 1000 callout should have been an instant toga party.
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.
> 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?
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> 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.