This statement would appear to be flat-out false.
JSF.mil > Leadership > Former Leadership
By the time Mike Hough was on board, the requirements were largely set - the JIRD-JORD process was largely complete and the PWSC designs were well under way.
LO, thanks for your reasoned, polite, and unemotional reply. I stand corrected. My memory clearly failed me. I regret that.
Nevertheless, there is often a lot more to the "set" requirements than meets the eye. The C-17 for example requirements that were firmly "set". Once development began those basic requirements remained the same, but lots of sub requirements got added. Like fly-by-wire flight control. C-17 was bid with mechanical flight controls and a stability augmentation system. USAF demanded fly-by-wire. C-17 was bid with a few basic missions. Then they added aeromedical evac, HALO, SOLL, and more. And unlike C-5 and C-141 which had kits for different missions (like cargo airdrop, CDS, troop drop, aeromedical evac, etc), the C-17 was required to do all these additional mission without kits. Everything had to be part of the airplane all the time. And even though over 30% of its operational life would now be spent at low altitude and high speed, it still had to meet it original service life. Surprise surprise, it got heavy. And worse, it got tail heavy because all that equipment for all those other missions were stowed in the empty tail area, requiring significant redesign. (The entire volume aft of the ramp is unpressurized in the C-141 and C-5. Essentially all the volume aft of the ramp is fully pressurized in the C-17).
Have the requirements shifted nearly constantly? Yes.
That's also bilge. RP asked you for evidence and you ignored the challenge, because you don't have any evidence. The requirements have remained stable except where they have been relaxed.
Perhaps my memory on that is faulty also. I'll do some digging and see what I can find, but here's what comes to mind just off the top of my head: Was the windshield bird strike requirement "set" in the JORD? Or was that a later UK requirement and the reason the F-35 now has a bow in the canopy even though it is a one-piece canopy like the F-16 and F-22, neither of which have bows. Was the requirement to include a magic helmet part of the JORD? Was the requirement to have full spherical passive sensor coverage (DAS) part of the JORD? Was the requirement to have a single sensor (EOTS) that functions as both a FLIR and an IRST part of the JORD? Was the requirement to have a stealthy datalink (MADL) part of the JORD? Did these systems add weight, cost, risk, and time to the program? Was the requirement to have an ejection seat capable of safely handling a 103 lb to 285 lb pilot part of the JORD? Now, having been asked the questions, will you, using your wording, "ignore the challenge?"
And BTW, while I can play your adversarial games, it is rather tedious doing so. I've now countered with what you call a "challenge." I'll leave it at that.