Originally Posted by
airsurfer
... I rather thing two hours: extra landing and takeoff costs 2x30 minutes plus one hour stop makes two hours. But, let it 4 hours, this is not the worst issue.
Taking 1-2 extra sets of crew, hunderd(s) tons of extra fuel makes such flights more costly than one stop flights on a similar distance. The extra fuel and extra crew costs paying passenger space, decreasing profits of the flight...
Two more factors in favor of the non-stop:
1. Routing via an intermediate airport is inherently longer than a non-stop. How much longer depends on how close to the non-stop route the stop is, but there's always some added distance. The optimal non-stop routing for such a long flight, under a given day's wind conditions, can push an intermediate stop that is right under the great circle route several hundred miles away from the best non-stop routing. That's a big part of where the four hours number comes from.
2. Any connection runs a risk of a missed connection because of delays in the first leg, of lost luggage at the connection point if you check it, of the aircraft for the second leg having a problem or not being there because of an earlier problem, of weather at the connection point interfering with a smooth connection, etc., etc. That's a big part of why people prefer non-stops: if the plane takes off, you have a much higher likelihood of arriving at your destination more or less when you expect to. Is there anyone here who has never had a problem with a connecting flight? Case closed.