Have also been a pax in an aircraft that dumped once - glad to say we were informed by the Flight Deck
I'd have to agree with this comment. Each time I've had to jettison fuel, I've been lucky enough to be in a position where I was able to make a PA before starting the dump and explain that people behind the wing at a window seat would see 'vapour' coming from the wing as we “lightened the aircraft weight for landing”. (I carefully avoided using the word 'smoke', as English is not the first language of many of my airline's pax, and I class 'smoke' not far beneath the word 'bomb' as being a word to avoid if possible when talking over the PA whilst airborne.)
As for landing overweight -v- jettisoning after an engine failure immediately after takeoff, I have to admit to have given that situation some thought. (I fly a two engined widebody.) All things being equal, (ie, no high terrain in the overshoot area, a 3600m to 4000m runway, as is usually the case at most airports I find myself using these days), I find myself leaning rather heavily towards the overweight landing option.
My reasons? As opposed to the simulator, where the check captain presses a button that gives you a nice, clean-cut “engine severe/separation at V1+1”, in the real world, the most likely reasons that might cause a usually very reliable engine to give up the ghost at V1+1 have a very good chance to affect the other engine as well. Among these I’d include multiple bird strike, contaminated fuel or foreign object damage. This FOD could be from a blown tyre, (either from my own aircraft or an earlier user of the runway), or debris on the runway, as allegedly caused the Concorde disaster at Paris.
Whatever the cause, I think getting back on the ground
without a rush, but without undue delay, is a better option over trolling off to a fuel jettison area that might be quite a few miles away from a quick landing should things start to go pear shaped with the other engine or some other vital system. For those who quote the fact that the aircraft is certified for 180 minutes ETOPS, I think that losing an engine in the cruise is a very different matter (for the reasons I quote above) to losing an engine immediately after takeoff.
I also accept that I may have to re-think these ideas when I start to operate ultra long haul twins (as I soon will be), for these will present me with takeoff weights so much above the recommended max landing weight that the approach speeds will be so high that jettisoning might be a ‘must do’ in all cases except something like an uncontrollable fire.