Originally Posted by studi
There is absolutely never ever the need for [XYZ] Never. So why give the pilots the possibility to do so?
studi, am I right that you are really new to this?
Let me try a short precis of how such systems need to be designed.
First, there are sensors which sense *some* of the system state (including *some* of the intentions of the operators). Then, on the basis of the sensor readings a designer has to decide
(a): what aircraft configuration makes most sense, and
(b) what the hazards are from hisher choice in (a).
Those hazards would be situations in which the aircraft configuration chosen in (a) mismatched the situation the aircraft really was in. And for all the hazards you can think of under (b), you then have to show:
(c) how the hazards can be mitigated.
You want to say there is never a situation in which one wants reverse on one engine and thrust on the other. That may be, but then a designer who is explicitly considering this undesirable situation would need to determine what is best to do. There seem to me two possibilities:
(i) the pilot wants to stop;
(ii) the pilot wants to go.
The hazards are equally obvious:
(x) if you inhibit thrust, the (most obvious) hazard is a situation in which the pilot wants to go;
(y) if you inhibit reverse, the (most obvious) hazard is a situation in which the pilot wants to stop.
How would one design a configuration to admit both these possibilities while mitigating the hazards? Answer: the designer must let the pilot choose in the given situation. Heshe can't choose in advance from hisher comfy desk.
PBL