There's a lovely example of it happening for real at the end of Die Hard 2; where John McClain has blown up the 747 and the other aircraft are using the flaming wreckage as landing lights, landing through the billowing smoke.
Watch for it next time
What's more those vortices can last for 10 minutes or more, just lazily rolling down the length of the runway. There are rules on how close light aircraft can follow heavier ones when landing, as vortices from a big plane can easily hurl a smaller one into the ground.
Well shiver me timbers. The circuit-board swap actually WORKED. I've got everything back!!! BIG thanks to everyone who gave me the confidence to actually try it.
Didn't need soldering at all - all the connections from the CB to the drive wre the compression type where the contacts are just pushed together when it's screwed down.
It also seems the problem wasn't caused by general wear & tear on the drive, it was....... leaking watercooling fluid..
Been a while since I did any. In most of the videos I've seen it just pops off so possibly (hopefully) it depends on the drive. It should arrive in the next day or so so we'll see.