Right. Total project cost is around $750m to complete it. GIve what its potential is, may be one of the most effective research projects for weapons in a long, long, time.

50 years from now they better have X-Wings and TIE-Fighters!

While we are wasting money on useless crap why don't we just spend 1 trillion dollars per plane. We could probably have real stealth planes with optic camoflauge and robotic pilots that can be in the air 24/7 which can be controlled by a super computer like a Skynet equivalent or something.

See! I can think up new and interesting ways to waste money that was taken from people against their will. Where is my job at the Pentagon?

Hopefully these planes do have a long lifespan. However, in order to save money, why don't we just slowly start selling off our older planes to (friendly) foreign nations. At least we'll get something back. Not much, but something. It's better than leaving them to rot in the boneyard. In fact, I don't know the military doesn't do that with everything from guns to tanks to planes. I'm sure some former Soviet republic out there would love to have 30-40 year old American technology.

I was only referring to strike and air superiority jets not bombers. Those airframes are under a lot more stress due to a combination of supersonic speeds, high G turns and used a lot more for training and war purposes.  I think those figures you've given are misleading as they are not from operational years but rather from when first flight tested and also they weren't built all during the 70's but over a decade or so. Also there are reasons why those aircraft are being kept in service beyond their lifespan, one being the fall of the Soviet Union which meant there were no equal adversary to warrant a mass purchase of new 5th gen aircraft and the other being the delays in procuring the F-35. If you look at fighter jets during the Cold War which basically lasted 46 years there were 2nd, 3rd and 4th generations developed which basically gave roughly 15 years lifespan per gen with say another 15 or so years of use before being completely phased out.

That still doesn't change the reality that the designs lasted for 40-60 years and are still in operation. The same should be said for the F-35 design - that it'll last between 30 - 50 years before being fully decomissioned. Very true the airframes last shorter periods of time (unless they're B-52s), but again, the R&D cost stays mostly static for the design.

@bolded. I don't know if the US Navy have changed their minds, but I doubt the F-35 will replace their F/A-18s. They always go with planes with 2 engines for safety purposes, landing in an aircraft carrier is a lot harder than landing on the ground so they go with planes with 2 engines to minimize incedents with malfuntioning/damaged engines. That's how the F/A-18 were "born", the YF-17 was the looser of the contract that gave birth to the F-16 but the Navy refused to adopt it and choosed and further developed the looser YF-17 (with 2 jet engines) until it became the F/A-18.

About the costs, when the F-15 was introduced its cost was around 50 millions. Now it's +100 due to many factors but specially electronics and up-to-date upgrades . They have upgraded/replaced the radar many, many times and that made it more and more expensive. And the same will happen with the F-35, those 122 million for the F-35A will go up to 150 before 2020 with the F-35D.

F-35 has a Navy variant. It is intended to replace EVERY fighter craft in all US services with the exception of the F-22. Navy will use the F-35C variant.

http://en.wikipedia.org/wiki/Lockheed_Martin_F-35_Lightning_II#Variants

Since the beginning, Soviet planes had better aerodynamics making them superior in close range combats, but the US planes had better electronics making the superior in mid-to-long range combat.

No other plane can do the "cobra" besides the SU-27/30 planes

Thanks for the link. It seem that they have changed their minds.