Originally Posted by
Lonewolf_50
(ref the 225)
It appears to me that maybe those "protections" are overrated.
LW in general I agree with a good bit of your post, however I don't think you have quite grasped that this accident happened to and L2, not a 225. On the latter, the protections are not overrated (the former has none). To decry them is to deny the benefits of technological progress.
For example (on the 225), if you engage VS alone but have too little collective, the airspeed reduces until about 65 kts, then IAS automatically engages and stabilizes the speed at 65 kts (actual speed varies slightly according to dv/dt). That's fairly easy, but what if the collective channel is not working for some reason? ( its an MEL allowable defect, although I've never known it to be inop). Well then you have VS engaged on the cyclic with insufficient power to meet the needs. This time the IAS cannot engage automatically because the collective channel is inop. So what happens?
Well, what would you want to happen? You wouldn't want the IAS to go much below Vy, and that's exactly what happens. The VS mode starts to soft-limit the IAS to around 65 kts. So even though VS is still engaged according to the AFCS status zone, nothing engaged on the (inoperative) collective, the protections prevent the IAS getting too low.
So if, after that brief explanation of some of the protections, you still think they are over-rated, then perhaps you would tell us what sort of protections you think should be incorporated?