Well I wouldn't call it a desastrous hatching, more like OMG, its time to assist... LOL..... I'm not saying assist right now, I'm saying once it's past the due date and they are upside down or having some technical difficulties..On day 16 the embryo is just about fully formed and starting to turn towards the fat end of the shell. Please don't candle or disturb them much during this time, since if they get turned around in the wrong end it could mean a disastrous hatch.
"Is it close"? Not even remotely.In another week, maybe!