A pilot should have an approximate idea of what his/her V2 & Vref for a given weight rather than rely solely on a FMC generated speed. If the FMC generated speed is different by more than a couple of knots the difference should be investigated & resolved. For example it may be that a different flap setting from normal is being used or it could be as in this case the FMC is giving duff gen because duff gen was inserted in the first place.
I'm not suggesting pilots should know all speeds for all weights but if an aircraft such as a B717 is operated regularly at weights that don't normally change that much then any abnormally low speed should be questioned.
Surely if multiple legs are being operated over the same routes day in day out & the FMC throws up a speed which you don't very often see (if at all) you say "haven't seen that before what's going on" or whatever!
Too much reliance on computers nowadays & not enough <thinking>. Isn't that what experience & airmanship is all about?
My 2 cents
