The Eurocontrol is discussing about the implementention of CDA ,continuous descent app,which will mean FMC descent from t/d to G/S intercept.
It's very nice,from T/D you'll receive cleareance to descent at 2500' (for ex.) and intercept the ILS,or call on base leg.
You will descent at idle thrust ,in FMC descent,which has in the descent profile a series of 'gates' through which all the planes,no matter type,must pass. This way the controller will be able to monitor the descent,and plan his flights,and not intervene in your descent.
The planes arriving or departing will fly through virtual tubes,with no further need for atc intervention.
We did some tests in the sim for the eurocontrol,it was interesting,and now they are also instructing the atc controllers from our area,in order to fully implement,for testing,these procedures.
So flap42,you should better use the vnav profile,and if you want to avoid high rates of descent you should change the descent speeds ( i.e.77/300kt for 737 will give you a nice descent ).The vnav profile will take you through the mandatory altitudes ,so comply also with the STAR's.
Brgds Alex