re: F-35 Joint Strike Fighter Thread
When the JSF was being conceived, the USAF was to have several hundred Raptors and legacy Eagles, so the air dominance role was adequatly catered for. The biggest partner, the UK was to have it's Typhoons for that. So they now researched a concept for a fighter bomber that would be "good enough" in areal combat but could focus on it's primary mission and be rather low priced at that.
Then the Raptor # got cut short, so the F-35 will have to take over a somewhat larger part of the areal combat role as well. All the partner nations involved and also needed to keep the cost down want the JSF as a true multi role fighter, mainly replacing legacy F-16 (type) fighters in service with these forces.
That's how the JSF grew "out of it's design shoes" to some extent. And changing requirements after a design has already been conceived is truely difficult. Even more so today when these programs drag out over ever longer time frames, partly because of loosing bidders protesting the decision, or a changing political landscape, or whatever. So there's constantly new tech that wants to be integrated wich wasn't available when the design was made. Instead of just choosing a design and then promtly manufacturing it.
We have a similar problem with the Typhoon here really, only going the other way. When it was thought up as the "Fighter 90" (reference to the time frame when it was to be introduced, in Germany at least) it's job was to replace McDonnell F-4Fs & Tornado F-3s in the air-defense / intercept role to defend western europe against intruding warsaw pact fighters & bombers. The Tornado fighter bombers were still rather up to date and a replacement could be thought up in the future.
Then the SU collapsed, forces were shrunk, money was cut, modernization was delayed into the future. When the EF finally became ready, the Tornados became rather dated as well. There's no money for two types any more, so the EF has to become a multirole fighter taking over both roles. And introducing all that A-G stuff into the EF is causing quite a mess. Not to much in the UK it seems, as the Brits just hang the stuff onto the plane and drop it. But much more so here in Ger, since just every minor thing has to be contracted, company tested & approved and so on. So the plane gets more expensive, numbers get cut again, and depoyment dates get delayed into the future.
On a side note, I think the consolidation process that took place over the years in the domain of aeronautical industries in particulat, and defense industry in generall may be a contributing factor to that mess, since competition has decreased. Even though said procvess may, on the other hand, have been the only way to keep these ever more expensive and challanging programs going, in times of shrinking butgets.