LO,
Your point about over-specification and compounded requirements is well made, but I'd respectfully suggest, having been very familiar with them, that JSF requirements were not as 'off beam' as those for F-22 and B-2.
The JORD/JIRD process used for JSF was exhaustive and ran for around three to four years, where any number of trade studies were conducted to ensure that the 'unguided requirement' scenario was less likely to arise.
The JSF programme's main problem, in my view (and others will differ) was a lack of systems engineering discipline in the early days after contract award, which led to requirements not being correctly 'decomposed' or flowed down into the design teams. The main reason for this (again my view) was an extremely optimistic schedule that put the designers under huge time pressure right from the start.
On top of that there was a lack of focus on weight (very regrettable on a powered lift aircraft, and another systems engineering failure) and an over-emphasis on manufacturing (which led in many cases to weight growth).
The other thing to remember about JSF/F-35 is that it is (quite rightly) being fully reported in an open press. Programmes such as F-22, Typhoon, B-2 and many others were quite successful in hiding their problems.
Please note that I'm not denying F-35 has problems and challenges. It does and they are significant. But a bit of perspective might help.
Best Regards as ever
Engines
Last edited by Engines; 30th Dec 2012 at 13:57.
Reason: Spell check