Hey,
Doze!
I sure hope I am not one of those that assert the 'bus FBW system and laws were soley designed by computer geeks with no pilot inputs.
I do question how many of the pilots had previously flown a pure FBW system while the control laws and so-called "protections" were being implemented. I also question how many tweaks and changes were made during the prototype phase and such - those suggested or even demanded by said pilots after actually flying the beast at the limits of those "protections" ( how I absolutely hate that term - grrrr).
Folks can point out that my ancient jet was not designed for the same operational needs and requirements as a commercial airliner. Nevertheless, just divide our "limits" by certain values and you get the 'bus "limits". And BTW, we had less ability to override those limits than the 'bus drivers. only thing we could do was manually lower flaps and, if HAL let us, we could use the pitch override switch to command horizontal tail movement ( HAL would not let us unless AoA was above 30 degrees).
We did not have four distinct reversion modes and a fifth if you count manual THS commands and I guess rudder. Fer chrissakes, look at the 'bus reversion chart in the manual! 26 footnotes! AoA alone has three, plus note (a).
Just a few:
1 Limited to 30 degrees nose up (reducing to 25 degrees nose up at low speed) and 15 degrees nose down
2 Limited to +2.5G and -1G with salts retracted. Limited to +2G and 0G with slats extended
3 Between alpha prot and alpha max, the sidestick commands AOA directly. Autopilot disconnects. TOGA lock is activated when AOA reaches alpha floor. This protection never allows alpha max to be exceeded. Stall AOA is greater than alpha max
4 When speed goes above VMO + 4 kts / MMO + M0.006 the autopilot disconnects and nose up input is made by the envelope control system. Bank angle is automatically limited to 45 degrees (instead of 67 degrees)
5 Available in CONF 2, 3 or FULL between 100’ and 2,000’ RA. Inhibited below 100’ RA or when both RA’s failed. “SPEED SPEED SPEED” repeated every 5 seconds until aircraft energy (speed and thrust combination) is increased. AOA protection still underpins this protection in NORMAL LAW. Also inhibited when TOGA selected, Alpha-floor or GPWS triggered.
6 An automatic nose down command is introduced to increase speed. No reference to AOA, only speed. Operates 5 to 10 kts above stall warning depending on weight & slat/flap configuration. The pilot can override.
BEAM ME UP!!!
Convince me that the AF447 PF was considering all those exceptions to the "rule".