What was the reasoning?
My personal guess is that it was internally totally disparate teams inside Boeing and neither communicated about the change. Is that bad? Certainly. But how often does that happen in big companies? All the time. Sadly it might have had a part in causing fatalities in this case, but doesn’t make it any less common.
Either way, it’s not like the change definitively had any bearing. Turning off all electronic control was still the training given to pilots and then reverting to manually turning a wheel that controlled the horizontal stabilizer via cable. It’s not an easy thing to do (turn the wheel manually), especially during a nose dive, but it’s been done before in an emergency and pilots are trained on it.
Ultimately, the FAA had a prestigious record due in part to having excellent checks and balances. Whoever decided to move away from DERs to ARs ultimately should get the brunt of this blame, but sadly, that’ll never happen.
And the root cause reason for that is Boeing was hiding changes in order to make the same type certification. Many decisions were made not in the interest of maximizing safety but in minimizing visible changes. This is one of those.
It would have been safer overall to have a new type, and then they could've had a cut-out switch just for the MCAS and trained pilots on how to use it.
Before 2004, those Boeing technical employees who worked safety on behalf of the FAA were called “Designated Engineering Representatives,” or DERs. Though paid by Boeing, they were appointed by the FAA and reported directly to their technical counterparts at the FAA.
What changed since 2004 is that safety engineers, now called Authorized Representatives, are appointed by and report to Boeing managers.
The opaque bureaucratic name for this new structure — Organization Designation Authorization (ODA) — masks the significant change: Instead of having individual Boeing employees authorized as FAA reps, Boeing now has an entire organization within the company so authorized. The individual FAA Authorized Reps — Boeing engineers — report up the chain to their Boeing managers, not the FAA.
source: https://www.seattletimes.com/business/boeing-aerospace/engin... Interesting read.