Not sure about the 74 classic engines noise issues. But I seriously doubt that "NAV" equipment would be a factor. GPS is about as accurate as you can get, and I've seen some classics fitted with Honeywell FMS, the same units, or nearly identical, as we have in the -400s. I've also seen a moving map TV mounted in the pedestal forward of the throttle quadrant.
Yep, just like the ones I used to fly.
They were converted 767 Honeywell FMS's. BA had 15 Classics converted to FMS and the mob I worked for ended up with three of them. Rather civilised.
