It’s 2,136 nautical miles from PHNL to KSFO, almost all of it over water.
What happens if we have an emergency?
The simple answer is that we’ll either turn back to HNL or continue to SFO, whichever is closest. To decide, we take into account the winds, assuming we have to descend to 10,000’ & drop a point where it’s an equal amount of time to either. If past the point, continue to SFO. Otherwise, turn around.
This is called our “CP” or “Critical Point”. It’s also sometimes called an “Equal Time Point”. It shifts from day to day, based on the winds, but out of the islands it’s usually at around 140° West. That’s about halfway in terms of mileage; the Coast Guard used to put a ship there in the early days, known as “Ocean Station November”. It served as a weather ship, had a beacon for navigation & was on standby for rescues at 30° North, 140° West.
(PanAm 6 did ditch near the Cutter once in 1956, with all aboard surviving)
Today, the Cutter is no longer there. Also, our CP is a little West of the mid point in terms of miles, because the winds are a light tailwind. If the winds were stronger, it would be even further West, because turning around means we have to battle a headwind now, slowing us down.
LAX is actually further from HNL at 2,217 nm, where SFO is 2,081 nm because it’s further West than LAX, so SFO is our best bet.
Hope that helps!