Quote Originally Posted by Maeda Toshiie View Post
Age of airframes. You can manufacture new ones (assuming that the production line tools remain) or "zero-hour" them (which also practically means remanufacturing them).

Design. There is a limit as to how much you can squeeze out of an existing airframe in terms of flight performance, space for avionics, etc. This is partly what killed the F20, ie an F16 with a brand new airframe and resulting growth potential. You can't plug in F22 engines into an F15E and expect a performance boost, even if the engines fit.
Both spot on points.

I won't go into the operational capabilities or political aspects of either the F22 or F35, but from an engineering, manufacturing and maintenance standpoint both aircraft have some significant advantages over the current crop. Several years ago I worked for a company making aerospace components was involved with several projects for the F22 and the cancelled Comanche helicopter.

There has been tremendous effort placed into design for manufacturability, reliability and maintenance on both the airframe and engines of the F22, and now the F35. Manufacturing capabilities and efficiency has made huge shifts in the past thirty years and constructing new F22s and F35 will be little more expensive than the older aircraft (in adjusted dollars), the real expense is in materials (lots of titanium and composites) and the advanced technology aspects.

The designers of this new generation of aircraft have actually been seeking significant input from the assemblers in the factories and technicians if the field; operations on the F15/16 that were intended for one person but actually take two, really can be performed by one on the F22/35. The engines used in the F22, and as the basis for the F35 engine, have 40% fewer major components than most prior jet engines and been designed to keep them flying with minimal maintenance man hours by shifting most of the critical components to the bottom of the engine, thus eliminating the need to remove the engine unless a complete overhaul is required. The use of modular systems makes component change out in field conditions very quick and one small innovation that I really liked was the elimination of safety wire with the advent of a new type of connection plug; no need to find lost wire twisting pliers any more.

As an aside, my cousin is a Harrier pilot in the USMC; I'll get his impressions the next time he's home on leave and we have a chance to talk.