V/S mode

[EHM-1001 Robert]

Hi there !

I was always curious why the big birds have a button for V/S Hold and ALT Hold on the A/P panel. If you set a new altitude and engage ALT Hold, it is automatically follow the new altitude according to the given V/S number, so both button will illuminate. Is it real ? Is not there an A/P function that I simply start a descent with a given sinkrate, but without a given altitude? I do not remeber well, but maybe the PMDG planes can do this.

So, how is it in real world, and in sim world?

[EHM-1281 Cyriel]

would this not be a little bit dangerous? Suppose the plane is set to descent at 1800f/pm and it wil not stop at a given altitude. anything goes wrong (pilots sleeping, sick). and the plane will automatically crash itself inthe ground. Not a good plan I think.

The PMDG also does not have this function. I can descent automatically accroding to the flightplan in the FMC. BUt you always need to set an altitude in the autopilot at wich it will stop regardless of what is in the flightplan.

Dunno about real life can imagine it is simmilar.