@ Gryphon
Good thots overall, but we have to face reality of the man-machine-interface of the aircraft.
As you know from reading my user background, I am very familiar with FBW and all it entails. And as you rightly point out, many folks do not understand. They think FBW is a glorified autopilot. It is not.
The curent architecture of the 'bus could easily allow for one or two backup modes, with last one being "direct" but with specified "gains and rate limits" based upon gear up or gear down and zero dependecne upon air data. If all the computers go tango uniform, all bets are off, but with just one and a clear indication it was the sole survivor, then a condition such as we had for the last 40 years would exist. No force feedback because most everything was a hydraulic pressure on an actuator. No auto throttle or VNAV, pure manual with the "standby gains and pitch rates". After all, no mechanical connections so you depend upon the electrons.
The current 'bus laws are confusing once outta "normal". Sheesh. Doze will jump in here and assert that the engineers programmed everything with pilot assent. But I question how many ever flew a FBW system with zero mechanical backup.
Seems that the engineers tried to preserve every "protection" they could as the overall system degraded. But there were a myriad of combinations and last thing I need is a multiple choice quiz when things go to hell in a handbasket.
So I think a reasonable reversion sequence would be:
- Loss of data, be it AoA or speed or altitude or attitude and maybe gee sensors. Autopilot disconnect and a clear indication of the reversion mode. Latch existing air/gee/AoA data as it existed for 10 or 20 seconds. Then go to the standby gains/rates and standby gee limits. No stall protection, overspeed protection, roll angle protection, no autothrottle, just a nice smooth flying jet with rate and deflection gains fixed upon gear up/down. You would think you were flying a neat design from the 70's or 80's.
What is wrong with that?
What I see from the drivers is the VNAV and other otto features that might help a single seat pilot as I was, but I was not carrying a few hundred pax.