Originally Posted by
Mad (Flt) Scientist
I would be very cautious in concluding anything about actual aircraft system behaviour, in an abnormal condition, from behaviour observed in a simulator whose intent is training not engineering investigation. The only way to know for sure what the system would do is to actually do it by test, the next best is a full-up engineering simulation. A FFS is a poor man's version of the latter when it comes to this kind of thing.
Is there not a presumption that, regardless of how a FFS might behave, the real aircraft will act as described in the FCOM ? The latter makes it clear that, with the gear selected down, the only thing that prevents hydraulic pressure extending the gear is IAS of 260 kts or more.