[Batrachian]

Your right, but I'm referring to commercial designs where economics are everything. The examples you cited are all excellent designs, but economics plays a much smaller role.

You know why they can't come up with a fighter that's significantly better than the F-15? Because the pilots couldn't stand the gees. The avionics and stealth of the F-22 is far superior, but the performance can't be. They would have to remove the pilot altogether, and that's in the cards. As for the B-52, they had a replacement for it in the 1960s, the B-70 Valkyrie, which was awesome, but it was canceled in favor of investing in ICBMs.

[freedumb2003]

Good points all.

I guess I was reinforcing your thought -- something about aeronautics in the 60s-70s that made them push the envelope -- pretty much to the limits of physics.

Thats why the 747 continues to operate as an airframe design and why all the other craft I pointed out continue as well.

Heck, the 727 is still operating for FedEx, some charters, as well as a lot of Latin American Airlines.

[zipper]

The avionics and stealth of the F-22 is far superior, but the performance can't be.

I recently spoke with someone with 70 hours in the F-22. He says the F-22 uses less fuel at 59,000+ feet at mach 1.95 than it does at 30,000 feet and mach .95. No F-15, F-16, F-18, F-14, or F-anything can touch that.