This may be a topic touched on elsewhere and if so I apologize. In my MD-11 the VNAV does not seem to engage. I originally set the altitude to 10,000 but when I engage autoflight the altitude does not change to programmed cruise altitude or blank out like the HDG and SPD indicators do when referencing the FMC. I have a cruise altitude entered in the FMC but the aircraft will only climb to what is manually set in the altitude window. The LNAV and Auto Throttles seem to work okay.What am I doing wrong?Thanks in advance,OSG

This may be a topic touched on elsewhere and if so I apologize. In my MD-11 the VNAV does not seem to engage. I originally set the altitude to 10,000 but when I engage autoflight the altitude does not change to programmed cruise altitude or blank out like the HDG and SPD indicators do when referencing the FMC. I have a cruise altitude entered in the FMC but the aircraft will only climb to what is manually set in the altitude window. The LNAV and Auto Throttles seem to work okay.What am I doing wrong?Thanks in advance,OSG

OSG, please read the docs that come with the aircraft, ALT window does not blank on any aircraft, Boeing,Airbus or MD. Unless you have set alt restrictions in the MCDU the aircraft will climb in PROF to whatever alt you set in the window.Read the autoflight section, understand your FMA, a little studying saves on a lot of trail and error and frustration.Regards

As was mentioned above, you should re-read the chapters on the Autoflight system.Part of what could be considered a "reason" the heading and speed windows "blank" but the altitude does not is that the only axis that is truly dangerous to an aircraft is the vertical one. At altitude, speed and heading being managed fully by the autoflight system won't kill you, but not knowing and fully authorizing the autoflight system to adjust the altitude could get you killed. For this reason, the altitude window is always active (on any aircraft with altitude hold) and the aircraft will only climb to or descent to that altitude in the window, even in VNAV (or PROF, in the MD-11's case). No matter what the FMC says, the altitude window will always win.