Funny you mention 587. That was actually the first thing I thought of. That was the one where the pilot slammed the pedals lock to lock in response to turbulence and ripped the vertical stabilizer off. Aircraft of similar size take off similar distances behind 747s all the time. The pilot really reacted badly in the case of 587 though his training was partly at fault. From wikipedia:
"The first officer repeatedly moved the rudder from fully left to fully right... The resulting hazardous sideslip angle led to extremely high aerodynamic loads that separated the vertical stabilizer. If the first officer had stopped moving the rudder at any time before the vertical stabilizer failed, the airplane would have leveled out on its own, and the accident would have been avoided"
>And involved in this one, though the situation is harder to assess:
427 was a hydraulic failure and any source of turbulence (e.g. weather) requiring rudder movements could have raised that issue. IT was part of a larger issue.
I originally said "Thank you from changing the wording from "implicated" to "cited" because they mean very different things." but you since edited your comment to say "cause" and "involved" which IMO is as accurate on average as "implicated" but with greater standard deviation.
I don't think it's reasonable to say that wake turbulence has never caused an issue for an airliner, when many hundreds of people died because pilots misapplied rudder in direct response to wake turbulence.
The correct systemic response is to note that wake turbulence is very dangerous for airliners because it may cause pilots to catastrophically misapply rudder.
(Sorry for my many edits to the parent, I didn't realize you'd already replied.)
I don't think it's reasonable to say that N=1 warrants a systemic change when the N in question was a human (as opposed to a mechanical failure which is as repeatable as the components and the failure conditions are).
I don't know but I suspect United did change their training after that. The fact that the pilot reacted the way he did is as much their fault as the pilots. IMO it is a training/human factors issue, not some fundamental issue with turbulence and current following distances.
American Airlines' training division had taught its pilots to react vigorously to wake turbulence, and among pilots generally, there was a widespread mistaken belief that, below the maximum maneuvering speed, it was impossible to do structural damage through the primary flight controls. Now that these misunderstandings have been corrected, we can hope this particular problem will not occur again.
On the other hand, I would guess that there is still a risk of people-thrown-around-the-cabin type incidents from abnormally close encounters with wake turbulence, and I do not know if the possibility of structural damage can be ruled out, especially if this were to happen at cruising speeds. I think it is probably safe to say that any structural-risk incident would have been within a whisker of being a collision anyway, in which case the measures to avoid the latter cover the former as well.
But the point of systemic thinking is to see when you've hit an area that's vulnerable to human and training factors and try to do the best you can to reasonably remove the risk. There are surely hazards that have caused less loss of life that we still consider dangerous at N=0.
Do you know whether ATC large plane same-size spacing guidelines around airports have changed much over the years? I don't know whether airliner spacing would have generally increased or decreased, but I'd be surprised if it hasn't changed at all.
Edit: I read more about these flights and I think I agree with you that I'm overstating the risk to airliners from wake turbulence. I was expecting to find increases in separation distances in response to the American flight and instead it looks like the only change made was a training change for rudder control.
>https://en.wikipedia.org/wiki/American_Airlines_Flight_587
Funny you mention 587. That was actually the first thing I thought of. That was the one where the pilot slammed the pedals lock to lock in response to turbulence and ripped the vertical stabilizer off. Aircraft of similar size take off similar distances behind 747s all the time. The pilot really reacted badly in the case of 587 though his training was partly at fault. From wikipedia:
"The first officer repeatedly moved the rudder from fully left to fully right... The resulting hazardous sideslip angle led to extremely high aerodynamic loads that separated the vertical stabilizer. If the first officer had stopped moving the rudder at any time before the vertical stabilizer failed, the airplane would have leveled out on its own, and the accident would have been avoided"
>And involved in this one, though the situation is harder to assess:
>https://en.wikipedia.org/wiki/USAir_Flight_427
427 was a hydraulic failure and any source of turbulence (e.g. weather) requiring rudder movements could have raised that issue. IT was part of a larger issue.
https://en.wikipedia.org/wiki/Boeing_737_rudder_issues#Secon...
I originally said "Thank you from changing the wording from "implicated" to "cited" because they mean very different things." but you since edited your comment to say "cause" and "involved" which IMO is as accurate on average as "implicated" but with greater standard deviation.