Originally Posted by
punkalouver
I think that is correct. If the general theme of what posters have been saying is correct, the controller’s plan(SW quickly taking off) put the FedEx flight at risk of a localizer anomaly at low in weather where that is not supposed to happen. The subsequent SW unannounced takeoff delay put the both aircraft in a position of serious collision risk.
I concur, there was a very serious risk of a collision. Using the NTSB data, it seems multiple slices of Swiss cheese had the holes aligned. It was the very last thin slice that didn't quite match up - but that was by pure chance.
1) Had the Southwest 737 commenced its roll just 4 or 5 seconds later the Fedex 767 would have been right on top of it at the minimum altitude before engine thrust arrested the 767's descent. Hard to be sure, but possibly the rear of the 767 and tailfin of the 737 might have been within 25-35 feet vertically. So just as dangerous as the 2017 SFO taxiway incident.
2) Had the Fedex FO taken a couple of seconds longer to call out "go around" the 767 would have sunk further towards the ground, possibly as low as the 737 tailfin. Also I can't be certain, but would the aerodynamic influence of an accelerating 737 on the runway disrupted the airflow to the extent that the 767 would have lost lift just as it was needed most?
Disclaimer - very long time lurker, very rare poster. Employed at EGLL, but dealing with what is disgorged by the aluminium / composite tubes, not in the air industry. Not often I can add something worthwhile that a pilot hasn't already mentioned. This has been a really good discussion.