Originally Posted by
DaveReidUK
Operating interleaved departures and arrivals on all of your runways sounds like a great way of unnecessarily p*ssing off the maximum number of communities surrounding an airport.
Maybe the way it's always been done isn't such a bad idea after all.
Only at Heathrow the communities know what that is.
With mixed mode runway occupancy times are leading, making the capacity ~25 arrivals and ~25 departures per hour. Two closely spaced parallels thus a higher capacity of ~35 arrivals and ~35 departures, as departures have to be coordinated with arrivals. Two independant runways will still have have an arrival capacity of ~35 but a departure capacity of ~45. The most important downside of mixed mode and closely spaced parallels is that the capacity reduces dramatically under limited visibility as (visual) confirmation of aircraft departing, landing and leaving the runway is essential.
The main problem with more than two parallel arrivals and departures is that your missed approaches for your middle runways can only go straight and thus interfere with your departure flows.