Just to be frank, in my 40+ years of aviation and 20k+ hours as a pilot, I never heard such a sillness as "the airplane will sit idle on the ground at the alternate airport for 2-3 days"... com'on... that's ridiculous... we are not talking of "third world" airports, neither of exceptional adverse weather like typhoon, hurricane and similar stuff. The only excuse I might find is relevant to the max. Duty times of the outbound crew ( the flight time only is in the region of 17-18 hrs.) as it might position from the original destination to an alternate airport... but those might be easily Newark and La Guardia, so here no problem. For more distant alternates (e.g. Boston) the break for the crew after the positioning flight and before their duty flight might cost not more than 8-10 hrs. as a delay. Of course, the company coordination of all this should be quite effective. And that's not a rarity in the long haul operations.
Last edited by capricorn23; 19th Feb 2023 at 22:20.