Except for the "excutive jet sized" thing, that's what I come up with too. I used the figures for a 747 as a proxy and came up with between 60 and 170 flights a day being sufficient to hoist 5,000,000 tons a year. It's probably closer to the lower number because the higher one assumes the plane would be fully loaded with fuel which isn't necessary just to fly for a couple of hours to discharge the cargo.
BTW, I much prefer a "space shield" approach since it can also be used to raise the amount of heat deposited and combat the coming ice age. Ultimately we might have a fine enough understanding to control climates quite precisely. Maybe even eventually some control of severe weather.