I just started flying the 737NG and I'm currently flying the excellent tutorials by Tim Metzinger (thanks Tim!).I've just done the missed approach on KMCO, and entered left the holding pattern to the north. I decided to do thinghs it bit differently... ;) and I selected the BITHO07 STAR in the FMC. (I'm using the updated KMCO file from navdata which fixes the rwy 35 error).I set the HDG to 360 and I enabled LNAV. As the subject says, I also tried to enable VNAV but it gives the error message: check mcp altitude. Although I'm still a beginner, I know that I should use the MCP ALT setting to clear the plane to the altitude on the next leg. I was flying at 2200 and I checked the LEGS page for the next altitude requested. The first two didn't have a "hard limit" set, but BITHO and COSMO had settings of ?/10000 and 230/8000. I set the MCP for 10000 and tried to enable VNAV: check MCP altitude... next: set MCP alt 15000, VNAV check MCP altitude, also tried: MCP ALT 5000...Then I did a LVL CHG to 10000 and that was the altitude when I arrived at BITHO.Now I would expect the new MCP ALT setting to be 8000, which I set but still when selecting VNAV: check MCP alt! Well... here it ends for me as a beginner... x( I've paused the sim and I started writing this message... :) Can anyone please explain to me what I'm doing wrong here?Thanks!Wanne.

>I just started flying the 737NG and I'm currently flying the>excellent tutorials by Tim Metzinger (thanks Tim!).>>I've just done the missed approach on KMCO, and entered left>the holding pattern to the north. I decided to do thinghs it>bit differently... ;) and I selected the BITHO07 STAR in the>FMC. (I'm using the updated KMCO file from navdata which fixes>the rwy 35 error).>>>I set the HDG to 360 and I enabled LNAV. As the subject says,>I also tried to enable VNAV but it gives the error message:>check mcp altitude. >>Although I'm still a beginner, I know that I should use the>MCP ALT setting to clear the plane to the altitude on the next>leg. I was flying at 2200 and I checked the LEGS page for the>next altitude requested. The first two didn't have a "hard>limit" set, but BITHO and COSMO had settings of ?/10000 and>230/8000. >>I set the MCP for 10000 and tried to enable VNAV: check MCP>altitude... next: set MCP alt 15000, VNAV check MCP altitude,>also tried: MCP ALT 5000...>>Then I did a LVL CHG to 10000 and that was the altitude when I>arrived at BITHO.>>Now I would expect the new MCP ALT setting to be 8000, which I>set but still when selecting VNAV: check MCP alt! >>Well... here it ends for me as a beginner... x( I've paused>the sim and I started writing this message... :) >>Can anyone please explain to me what I'm doing wrong here?>>Thanks!>>>>Wanne.>>I'm pretty sure I mentioned in the tutorial that VNAV did not work after going missed, but I haven't tried it since upgrading.Your workaround of LVL CHG is the correct way to solve the problem.

Thanks for the quick response Tim! You're right about the tutorial mentioning that you aren't able to use VNAV after a missed approach. I found it at the top of page 79. I hope that PMDG will support VNAV in a later version, or at least change the confusing CHECK MCP ALT message!By the way, on the same page of the tutorial (79), the following route is written:KTNT CURVE V35 DHP JVKZ AR1 BLUFI COMET ATHOL OMN KIZER ORL KMCOI can't find JVKZ anywhere but I guess it should be VKZ instead?Wanne.

I had the exact same problem on a roundrobin on LIRA.I used the URB5A sid, then went CMP - URB.But sometime before reaching CMP (i had set a hard limit of 3000B on urb) the VNAV disconnected with the said message.No way to reconnect it.I had to do it in manual.But i wonder why it got disconnected?As you i tried every conceivable altitude, to no avail.BRClaudio

Have you performed a missed approach just as I did? If so, it is a limitation of the current FMC which can't do VNAV afterwards.The CHECK MCP ALTITUDE message is just wrong... I hope that PMDG will address at least this error message in a future update.Wanne.

No, i was just going in for the first approach.And btw VNAV was engaged before, it disconnected when i passed one of the waypoints.BRClaudio

I'm just a beginner and I don't have a clue what causing your problem. Why not contact PMDG tech support and post here? I'm looking forward to the explanation.Wanne.

Hi all,Let me just pop in to describe the details of what happens...When one goes around, the FMC will immediately do the following- sets departure airport as arrival airport (useful to select an approach when cleared back to land)- sets the cruize altitude to the highest between - the airport elevation + 1500 - the highest hard alt constraint of the MA routing - the MCP alt- resets the flight phase to CLIMBConsidering the MA you mention, the highest constraint is 2500. Let's assume you correctly set your MCP (2500)...Given your cruize alt is 2500 you quickly reach TOC and transition to CRZ, and possible to DES phase, depending on distance of last MA wpt to airport etc... I assume that's what happened, as the FMC does not "count" a hold as special way relative to TOC / TOD calculation.Now... if you are in descent phase and you set your MCP higher (except in VNAV flyaway logic, but you have to be in approach) and try to engage VNAV, the FMC will wonder what happens...- aircraft is at altitude x- as phase is descending, the only possible MCP alt target should be at or under aircraft alt- the MCP alt is set aboveHence it won't let VNAV engage, and issue the message "CHECK MCP ALT"So... when going around, make sure you are aware of all the above so you understand what happens when engaging VNAV.In the following pic, I am indeed in VNAV, after go around. My MCP was (wrongly) set to 4000. Check where TOD is : very near TOC.Hope this helps.anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.comhttp://forums.avsim.net/user_files/75229.jpg

Hi Anthony,so if I understand you correctly:it is possible to engage VNAV after a go around?!? Is this a feature of the new 800-900 version?there are several parameters and the one with the highest alt is set as the new cruize altthe mcp has to be set to this new CRZ alt to re-engage VNAVI wish that I could have made a save of yesterdays situation so I could check the new CRZ ALT!I'm fairly sure that I tried a lot of MCP ALT settings which SHOULD have given the FMC clearance to go to this new CRZ alt but I always got the CHECK MCP ALT message... I'll try some more missed approaches to get some better understanding of the FMC. If you could only add a save game feature which would include all the 737 settings! (I did read something about this as a future feature on this forum, did I?).thanks!Wanne.

- VNAV can be engaged after going around (see my pic)- almost : if MCP is set higher than highest MA constraint, the new cruize alt will be the MCP alt. In principle, when doing landing checklist, set your MCP alt when GS engaged to the MA alt.- check MCP alt message will be issued if you are in the descent phase and try to set a higher than aircraft MCP alt and then try to engage VNAV.cheersanthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com