Tacho
My company sops explicitly forbid use of V/S at all above a certain flight level as the Aircraft will disregard speed to get its desired ROC, possibly leading to alpha prot etc.....
Shouldn't get to Alpha Prot. If a too high V/S is selected, the speed reduces, but when it gets to VLS the Autopilot ignores the V/S command and will maintain VLS. The FMA will still show the demanded V/S.
This though does mean that you are climbing to altitude with the speed way back on the drag curve. Not a good place to be - see the Pinnacle Airlines CRJ stall, double engine failure crash as a perfect example
Be careful out there!
T'bug
