Thank you for the link ORAC.
I always found noise dose a strange omission from the old FRES requirement (2002, and I'm sure there were versions before that). Not one of the KURs or URs mentioned it, yet the clock had been running on litigation for some years. Especially in the Air domain since the introduction of fully integrated ANR to meet the 85dB(A) limit, and the successful development of Digital ANR in 2001 to meet the proposed future requirement of 75dB(A).
What, a programme to mitigate a critical H&S Constraint when the legal limit was only being proposed? Yes, that's how seriously parts of MoD procurement took the subject. Alas, there were those who called it a waste of money and fought hard for cancellation. That's far worse than this Ajax fiasco, and I wonder how many aircrew and groundcrew, past and present, have very poor hearing.