The fault here is complex and involves the architecture of the system, the sensors, and how the behavior mimicked the older designed which reduced the training required which meant pilots were not as aware of both the changed flight characteristics and the MCAS itself.

Sure the FAA definitely needs to be questioned as to how they let this through without enough redundancy and pilot awareness but the engines are not the problem and certainly not the supports and bolts. Those are things that are well-tested before it even gets to the FAA and having extreme paranoia about the industry doesn't help.

Why should I trust you or FAA that the engine, the engine mounts and all the new updates related to this larger engines were tested when we know from previous articles that hings were rushed and stuff like the fire suppression system was not OK and the engineer was changed because was objecting.

I imagine that putting a larger engine is not as easy, isn't a larger engine heavier? the forces larger? Don't you need to test the engine supports, the wings, all the related mechanical support structure.

Your theory that only MCAS is an issue is already false since it was found that without autopilot 2 humans don't have the physical force to control the plane , so probably a new requirement in the FAA should be added that with autopilot off 1 single pilot should be able to control the plane. You may say this is related to MCAS but6 it is obvious that this item was not in any checklist for things to test so even with a working MCAS but other emergency where autopilot would be turned off you would get in the same situation.

Part of the problem is that Boeing changed the trim increment AFTER the FAA certification without FAA knowledge. I'm surprised a configuration change like that was allowed and wonder what level they were analyzed by safety engineers.

So there's not just the design workaround but there seems to also be process gaps that contributed to the situation.