Originally Posted by
Smokey Lomcevak
It’s also worth remembering that with flaps out of up and below the path - say from vectoring, for example, engaging VNAV will result in VNAV PTH and auto throttle speed.
Just to add to this point from Smokey - VNAV approach logic has a drawback: once you have approach logic engaged it behaves like it's either on the glideslope or at a platform waiting for the glodeslope. Youre committed to a path in space with no way to increase ROD or deviate from that path. If you want to go lower than the programmed path, increase ROD etc you have to select another mode and come back to VNAV later.