I typically descend using VNAV and allow the plane to follow it's proposed course. However I've noticed that after I've selected the appropriate runway, all of the speeds on the approach course are way too fast. It usually has a speed of 180kts for much of the approach until finally reaching a more reasonable speed, but by this time, I supposed to be practically on top of the runway. The problem if you haven't guessed is in order to slow down, the AP pulls up, and then I overshoot, big time. Actually, I more likely to be well over the runway before my speed adjusts. I've tried adjusting the speeds on my approach, but when I make the inputs in the FMC it says "invalid entry" or something to that extent. Does anyone know how to remedy this? Is VNAV not recommended for descents? Once entering the glideslope, you should be at your final approach spped, right? I have yet to have a complete takeoff and landing with this thing because I've always been working on figuring out one problem after another. This is the final piece and I'd like to get it down! I appreciate any assistance anyone may provide.Cheers!-Amro

I'll try this even though I haven't used the FMC in this particular NG.I normally program any FMC to set me on course for ILS intercept at about 2500 or 3000' AGL and then I fly the approach to touchdown using the LOC/GS function of the MCP. First I fly with the FMC flightplan to the LOC intercept and at that point, LNAV gets turned off because I have lateral guidance captured. Then I continue in level flight to the GS intercept and at that point, VNAV gets turned off (with vertical guidance captured) and I descend on the GS.Once on the GS, I use the MCP to control my speed. So I start slowing down (or slowing down further) and throw out flaps on the way down. I try to be stabilized in the landing configuration by 1500' AGL.I've never attempted to fly any jet to touchdown using VNAV because I am so used to using the MCP--or hand flying down the glideslope. But landing with the MCP is fun if you have a panel that performs a real autoland.Several real world pilots have told me that they never use the FMC to fly below 10,000 feet and that they use the MCP because they get vectored all over the place by ATC. My wife's nephew, however, who flies 747-400s and 777s tells me that he has flown to touchdown using VNAV although this is not common.This is probably imperfect and missing detail, but I have tried to convey a general approach (no pun intended) to you with this post.Good luck!Jonathan

I think I need to start flying the approaches without VNAV. I kinda got that feeling before. We'll see how it goes. Thanks for your input.-Amro

Pleasure. Glad to help somebody else after asking so much myself here!JS

It is possible to use VNAV for an entire approach. Remember to include altitudes with the speeds. It is a lot more efficient to use the MCP to control speed and headings until LOC/GS intercept, especially when flying online with ATC.---leo---

I ran through a tutorial (last name is Metzinger I think???) and used the VNAV approach and it worked fine. My only problem with it is the speeds calculated can't possibly be correct. And when I try to change the, it tells me that I can't.As far as using the MCP to control altitude, how does it know how fast to descend? Does it use the speed entered and the altitude given and choose the best rate of descent?Thanks again.-Amro