Originally Posted by Bugg smasher
I beg your pardon? You are starting to sound like my wife...
Sorry Bugg, you're probably on Prune to keep away from her!
Originally Posted by FIRESYSOK
Most charts in the US have a ROD table based on ground speed whereby you figure an initial descent rate and modify it if g/s changes or a restriction will not be met, using the VNAV information for advisory. (Don't get me wrong, this can be tricky)
Correct. It's difficult to judge what's going to happen in a couple of miles if the ROD is not quite right. Sure, you can "bounce" off the steps but equally, if you get high, you're just as likely to not get to the MDA before the 3° cutoff. That's the beauty of an altitude distance scale: get on it, stay on it and provided you don't bust the minima, you'll never kill yourself or your pax and give yourself the best chance of getting in (50ft problem not withstanding).