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