From those slides presented to the European Parliament, EASA said they found 4 significant technical problems that would need to be addressed:
- Lack of exhaustive monitoring of the system failures resulting in a stabiliser runaway
- Too high forces needed to move the manual trim wheel in case of a stabiliser runaway
- Too late disconnection of autopilot near stall speed (in specific conditions)
- Too high crew workload and risk of crew confusion in some failure cases, especially Angle of Attack single failure at take-off
And, according to the same slides, the solutions Boeing has been working on are:
- Extensive change to the Flight Control Computer architecture and logics (incl. Autopilot)
- Improved crew procedures (and associated training)
- Improved architecture and/or logics for the Angle of Attack system
It seems none of those directly address the issue with the high force that may be required to move the manual trim wheel. I wonder what Boeing's plan is regarding that. I'm guessing they will just try to convince the EASA that it is not actually an issue. But, if after the flight tests the EASA is still not convinced, things could get very messy.