I thought I had been told that there's normally an extra plane in LGB or somewhere on the West Coast... in general, I would have thought JetBlue could do better at resolving disrupted service in a place like Seattle that has relatively few flights than they could when a big storm knocks out JFK or BOS; obviously, they can't double the number of flights systemwide the day after a storm, but if they had doubled all flights to SEA for a day or two that would only represent 5% or so of their total traffic, and I would think they would have that much extra capacity.

Obviously, I don't really know how much spare capacity in planes, crews, staff, fuel, supplies, and so on that airlines maintain. I would assume that there's some margin in each of these categories, because you don't want to have to cancel a full day's flights if one plane has a problem, one pilot is sick, or one flight attendant has car trouble... So barring other problems happening at the same time, they should be able to put another plane in the air if they choose. (Of course, once they've sent the spare plane/crew off to SEA, then they're in trouble if somebody back at JFK is sick that day, I suppose!)

I guess I just assumed that JetBlue might be looking for an opportunity to combat a reputation for being unable to respond well in this type of situation; instead, it appears that they just decided things would work themselves out.