Originally Posted by LarryJ

No, we don't like the SFO procedure. I never have, for a couple of reasons.

The margin of error is small. If one airplane deviates from its course the other one must react almost immediately. It has worked because it is professional pilots with a lot of experience staying on their final approach course, using the localizer or RNAV tracks so those deviations are rare.

The amount of attention required to monitor the other airplane is a threat that can allow other errors to be made or to go undetected.

Several months ago, an Airbus was departing SFO runway 1R at the same time that another airplane was departing 1L. The departure procedures call for a left turn, for 1L departures and a right turn for 1R departures. This creates the diverging courses which makes the procedure legal. For some reason, that Airbus turned left, instead of right, putting the two airplanes into very close proximity. I've never flown an Airbus so don't know what kind of error the crew might have made which caused the wrong turn. The problem is that a single error was able to create a dangerous situation with very little opportunity to for either crew to identify and mitigate.

For both the arrivals and departures, I would prefer there to be enough separation between the paired airplanes that a single error results only in a loss of separation, not the threat of a collision.