SASless
Care to expound upon that statement?
I kept it brief because any more is beyond TS.
Exactly what would prevent the US builders from meeting those specifications and requirements?
Not knowing what they are in the first place. The US have equivalents, but they are (sensibly) less stringent than the Home Office's, and that is borne out by past Chinook requirements issued internally by MoD.
What are the specifications and requirements that are so "difficult" to meet by non-UK builders?
See above. I had TS clearance and was not permitted to know. It happens I do know, give or take, because the silly rules do not extend to stopping me viewing the test results as I had to sign production permits; but there is no point me quoting the specs 'cos the actual figures are removed and made available separately.
I hope you appreciate I'm not being awkward. To me, the Chinook, as built, is perfectly adequate. It is a hole the HO dug for us. My main point, which is perhaps unclear, is that while many moan and groan about MoD's procurers allegedly changing requirements and faffing around with specs, in fact they have little or nothing to do with it. They have to work within legal obligations and political mandates. What the Service may actually want or need (seldom the same thing, and seldom stated) comes a poor third.