Originally Posted by Flying Stone
I haven't done it in a jet so far, but my guess is not that much...
What added bonus would the "dive and drive" give you if you extended the level flight beyond intersection of CDFA and MDA?
If you'd have spent 5 minutes thinking about it instead of going off half-cocked, you'd realise that D-D has/had some merit. The idea is you get down to the MDA
before/under the 3° path, then fly into it, then go down it to land. Obviously you're not going to fly down the 3° path
then level off at the MDA
then try to land.
In the days of no VNAV, Dive and Drive had merit (not that we ever did it that way here; we used a 300ft/nm constant descent - sounds familiar...). It had the potential to be confusing: misreading the steps. But if you got that right, getting down to the MDA early certainly made some sense. Fly into the PAPI and Bob's your uncle, especially with cloudbase AT the MDA with good vis; you'd never get in on a 3° CDA to an MDA unless you were a bit low on the profile.
But now with the advent of VNAV, better to let the FMS take you down the 3° slope and hit the button at the MDA+50 if not Visual.
As for flying level at the MDA in a Cat C jet, my FCOM still says that's the procedure for an NPA. More importantly, it's no big deal!