Originally Posted by
GlobalNav
To be clear, the KC-46, basic aircraft, control system, A/P, etc were certified to Part 25, not military specs. Only the military pieces were certified by the military. But the basic design architecture of the 767 and 737 are decades apart and the amendment level of Part 25 which applied (certification basis) are quite different from the 737. I don't know for sure how the architectures of the flight control system, sensor data flows, trim system of the two models are alike, but expect significant differences with respect to how the MCAS operates. We'll see.
The second half of that is not correct. Per the Changed Product Rule, any new or changed system on the MAX (or the commercial cert of the 767-2C/KC-46) must step up to the latest revision levels of the regulations (there are exceptions, but they are rare and not applicable to MCAS). So you'll find the cert basis for MCAS is pretty much the same between the MAX and the KC-46. That doesn't mean they work the same way or are intended to do the same thing.
I'm staying pretty much out of this now - I've had some 'off the record' discussions with people 'in the know' - so I now know more than I can publicly discuss. However I can say most of posts related to certification are seriously lacking in accuracy.