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In this YouTube video, one can see the arrival at KJFK, holding patterns, and eventual diversion to KPHL of LH400, an A380. When LH400 arrives in the New York area, the pilots request the use of runway 13R, the longest runway at the airport, since, with the runways wet from bad weather, their aircraft is too heavy to safely use any of the others, and the winds (from headings in the 100-130 range, at 15 knots gusting to 28 or so) are better aligned with runways 13R/L than with any of the other runways.

However, KJFK is operating with runways 22R/L, and the approach controller refuses to switch to 13 ops to allow the A380 to land. Part of the justification given for this is that the bad weather had also shut down KTEB, causing KJFK to experience a large wave of corporate and private aircraft diverting from KTEB, and that switching from 22 ops to 13 ops for LH400, and then back to 22 ops, would have massively delayed the landings of the general-aviation flock. Without enough fuel to wait out the wave of aircraft coming in on 22R/L, LH400 is forced to divert, and lands safely at KPHL.

With winds from 100-130, though, using 22R/L rather than 13R/L seems illogical (especially given the presence of an aircraft unable to land on either 22R or 22L). Winds from the southeast to east-southeast would produce a quartering or even straight headwind for 13R/L, but a crosswind or quartering tailwind (even worse for aircraft than a crosswind!) for 22R/L; in addition, while the 4/22 runways measure 8,400 and 12,079 feet in length, the 13/31 runways measure 10,000 and 14,511 feet. The choice of 22R/L is especially hard to understand when you find out that the winds had been like this all day, making one wonder why they even started 22 ops that day in the first place. Even with 22 ops already in operation, one would think that the time needed to switch over to 13 ops would be more than justified by the safety benefits of landing aircraft on longer runways facing more nearly into the wind (especially when, as here, aircraft will be needing more landing distance than normal, due to reduced wheelbrake effectiveness on contaminated runways).

Why did KJFK run 22 ops that day when the winds favored 13 ops, and why didn't they switch to 13 ops even when confronted with an aircraft unable to take anything but 13R?

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  • $\begingroup$ This question deals with changing runway use: aviation.stackexchange.com/questions/9126/… $\endgroup$ Nov 27, 2021 at 0:58
  • $\begingroup$ This boils down to a question of traffic flow coordination in a terminal area. $\endgroup$
    – mins
    Nov 27, 2021 at 10:54
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    $\begingroup$ @StephenS: Still doesn't answer why the frick they were using 22 ops in the first place. $\endgroup$
    – Vikki
    Dec 8, 2021 at 0:51

1 Answer 1

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Due to close proximity, the runways in use at JFK, LGA and EWR must be carefully coordinated to maximize total volume.

In particular, instrument approaches to JFK on the 13s and departures off the 31s all go over LGA. Plus, arrivals on the 4s and departures off the 22s all go over EWR. So, there is a very strong preference for JFK using 4s or 13s for departures and 22s or 31s for arrivals, regardless of the winds. And all the diversions from TEB would have made it even more important to stay that way.

If the crosswind or tailwind on the preferred runways gets so bad that most aircraft will have to refuse their assignment, ATC will change things—and they know exactly where that line is. But to maintain safety with conflicting approaches and departures requires more spacing between planes, which directly results in lower total capacity. Many flights will get delayed, diverted or canceled, and the problems will cascade across the entire US airline system. This obviously has an enormous cost, both to the airlines and to passengers, so ATC will run things right up to that line for as long as possible.

It’s simply not worth paying that cost for the sake of one aircraft; instead, they’ll get diverted to another airport with more favorable winds.

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