When ever an opportunity presents itself to demonstrate that VNAV is not the all-wise guru that some think it is I grasp it fervently. It is an eye opener. There was often one place where we are on the ILS GP from many >20 miles out and yet the VNAV says we are 00's low. I point this out and ask what the youngster thinks. What should he do? There is much confusion. Why, how, what? I don't understand.
Well, look at the GP, the height & DME. Are they correct? Yes. Good. Then as we approach the OM the GP & VNAV merge accurately.
Bring your answer to school tomorrow and we'll discuss it. No matter, it has shown that the best computer in the a/c is between your ears. Never forget it. But then again, it has to have downloaded the Piloting APP first.