An interesting article on the use of the B-52 and B1-B. The long loiter time for the B-52 means that 1 B-52 with a load of smart bombs can provide rapid response for the whole country of Afghanistan.
I tend to think of the B-52 as a battery of artillery that can travel at 500 knots.
727’s burn as much fuel as a 767. they’re real expensive to fly. They were originally designed to fly on 2 engines in cruise but that never made it through production.
the 70 series DC-8 could pull 50 tons off the runway coast to coast. It was a great airplane but it’s just too old to keep up the maintenance on now. And the cost of overhauling an engine isn’t linear to it’s size. 4 engines cost more to overhaul than 2 larger engines of similar thrust.
Capital cost. They can get old ones for a song (well, in the low hundred thousands), since nobody else wants them. New planes cost in the hundreds of *millions *of dollars. That makes up for a lot of higher operating costs. Plus, they’re available immediately, not after a few years’ wait.
727’s and DC8’s were quite popular and made up the bulk of fleets at one time. You can’t just walk away from a fleet of them. It takes a chunk of money to replace a fleet. The only thing that made a lot of money in freight were envelopes and that segment of the market died with the introduction of cheap fax machines. So companies like Federal Express and UPS were the ones with a delivery network capable of delivering envelopes. That money bankrolled newer fleets of aircraft.