OK, now I know this is probably finger trouble, but for the life of me I can't figure it out. The CDU is programmed with the correct airports and coordinates, no SIDS and STARS just a direct route. Everything hunkydory. Depart and climb at 15 degrees with A/T armed, then I use HDG select to take me to the correct route, engage LNAV and VNAV and CMD A. The plane flies in AP mode nicely up to the right height and speed, and levels out. The flight continues as expected, but as I approach the airport, in this case YMML, the plane does not go into an auto decent, neither does the plane begin to slow down. I'm sure it's something I'm doing wrong, maybe it isn't I don't know, but if someone could offer some advice, I'd be grateful. Thanks guys...

Do you have a TD mark anywhere on your route showing? If so before you get to that point you need to change the altitude to a lower value on your MCP before you get to that point. I hope this helps before all the " Read the Manual" Mafi get here! :)

Do you have a TD mark anywhere on your route showing? If so before you get to that point you need to change the altitude to a lower value on your MCP before you get to that point. I hope this helps before all the " Read the Manual" Mafi get here! :)

Hee, hee, yes I know what you mean. It's all very well reading the manual all the time, there is so much to learn and sometimes it's easy to miss something or, in my case, forget it! Thanks a bunch...

OK, now I know this is probably finger trouble, but for the life of me I can't figure it out. The CDU is programmed with the correct airports and coordinates, no SIDS and STARS just a direct route. Everything hunkydory. Depart and climb at 15 degrees with A/T armed, then I use HDG select to take me to the correct route, engage LNAV and VNAV and CMD A. The plane flies in AP mode nicely up to the right height and speed, and levels out. The flight continues as expected, but as I approach the airport, in this case YMML, the plane does not go into an auto decent, neither does the plane begin to slow down. I'm sure it's something I'm doing wrong, maybe it isn't I don't know, but if someone could offer some advice, I'd be grateful. Thanks guys...

If your using V-NAV, just before the TD marker make sure you have reset your altitude in your MCP as in reduce it to your transition altitude etc, only by doing this will the descent begin in V-NAV mode..

All the above is true. When ATC clears you to descend to FLXXX just turn the altitude knob to that altitude, then next to that knob is a button marked Alt Inv I believe. That's altitude intervention and will start the descent.

All the above is true. When ATC clears you to descend to FLXXX just turn the altitude knob to that altitude, then next to that knob is a button marked Alt Inv I believe. That's altitude intervention and will start the descent.

Yeah if flying in the UK then you will find most but not all transition alts are around 6000 FT. You will also notice in the EFIS that on your flight path after TD there are several green circles, these are to indicate where the airfraft will being to retard after 10,000ft to help reduce speed before the intial decend into the airport. Normally i find setting the altitude to about 3000 if your path is taking you right in, then V-nav will certainly work well as the aircraft turns finals just arm the LOC and then App when Glide slope is alive :)

Yes. It varies by country. But if you're using FSX ATC, well it's not the best to say the least. Haha. But that's the basic practice to starting decent. Same goes for if you wish to climb higher during cruise.

When changing the altitude on the MCP. As long as you are before the TD point there is no need to press or push any other buttons. Just change the altitude on the MCP to a lower or whatever transition altitude that is correct for your plan. What you're doing is essentially giving the autopilot permission to change altitude as per the plan in the FMC I hope that makes sense? Phil

Really? Learnt something new then :) thanks!

When changing the altitude on the MCP. As long as you are before the TD point there is no need to press or push any other buttons. Just change the altitude on the MCP to a lower or whatever transition altitude that is correct for your plan. What you're doing is essentially giving the autopilot permission to change altitude as per the plan in the FMC I hope that makes sense?

I think that is a good way to describe it. In the US, you wouldn't start descending unless ATC cleared you to a lower altitude anyway.

Thanks all so very much guys. It's a very steep learning curve and it's nice to know there's somewhere to ask questions without being made to feel like a nonk

I think that is a good way to describe it. In the US, you wouldn't start descending unless ATC cleared you to a lower altitude anyway.

Yeah true i think that's the same for Europe. The lack of a good ATC in FSX just highlights these issues when using VNAV etc i know a lot of people who fly online almost take it for granted that ATC will give vectors once they get to a certain point after checking in with them. Can't wait for some software to make that happen for the people who fly offline most of the time :) Phil

I am having a similar problem when flying EWR to PHL except im doing everything in what seems to be the right way. I programmed for a 4L departure via EWR8 to BIGGY MAZIE and then PHL ILS 9R via DQO with a cruise of 8000 and i let the FMC automatically decide my speeds and altitudes at each waypoint. Near my T/D which is just before DQO i set the MCP to 4000 which is the altitude of the first waypoint after DQO (i planned to set the altitude of each subsequent waypoint until glideslope capture as was necessary to simulate being cleared). The problem is as im descending the aircraft speeds up by about 30-40 over the selected speed for DQO (when im already past it and the decel marker) and then at around 5350 it reduces vertical speed to -50 and none of the controls to intervene work. In the end after trying all my buttons its so late that the glideslope is impossible to catch and have to go around. Also after the EWR8 when i am in the (VECTORS) instruction and i use HDG HOLD to vector to BIGGY i notice that for some odd reason the plane always flys a heading 2 degrees less then what i set and therefore i cannot use the heading bug/line on the moving map to set an accurate course

Really? Learnt something new then :) thanks!

I noticed that if I have a t/d mark at a certain point ahead of me, andselect a lower alt, and then press alt intervention, it will start to descend,but usually at a fairly shallow rate, then when I pass t/d the rate will usuallyincrease to match the vnav course. If I select the lower alt, but don'thit the button, it will start the descent at the t/d mark, and at the normalprescribed vnav rate in the plan. If that makes any sense..So I think the alt intervention option can be used if ATC tells you to startthe descent before you actually reach the t/d mark. Will be a more shallowdescent from the start, but should be a good enough rate to keep ATC offyour back. Then when you pass t/d, it adjusts to agree with the normalvnav plan. But as far as the OP's question, yes, you have to select thelower alt on the mcp before it will descend. And ditto for ascending..It will not climb any higher than the mcp alt setting at the time. That'sto keep you from busting a temporary ATC alt during the ascent.

Makes sense. Thanks for the tips!