False 747X FMC "MAX ALT FLXXX" msg

[lensman 0]

Since I installed the MD-11, any 747X flight above 16,000 feet will be going fine, with the no warnings, EICAS or FMC issues. After a variable length of time, the FMC will pop up a message in the scratchpad saying "MAX ALT FLXXX" where XXX is 5000 to about 16000 ft below current cruise altitude. Checking PROG, PERF, RTE, LEGS, all show no problems. The suggested cruise altitude does not change. This is where it gets weird. If I ignore the message and I'm more than 100 nm from my destination, after a variable length of time, the airplane (pax or freighter, fully loaded or unloaded) will attempt to descend by itself. It ignores the MCP settings, and my changes to the MCP settings to get back control. There is no indication on the LEGS, PROG, PERF, or any EICAS page of deviation from the flight plan, altitude, or KIAS settings. The sim ignores HDG HOLD, HDG SEL, VNAV, LNAV, SPD, etc. The only way to get control back is to descend to whatever flight level was listed in the "MAX ALT FLXXX" message. Deleting the currently active route, canceling IFR w/MS ATC, and a few other attempts (switching between 2D and 3D mode) doesn't change anything. Once I'm at the "MAX ALT" altitude, the a/c behaves beautifully. But it will not climb. Example: KBOS-KATL, 747X freighter in PMDG livery. Optimum FL400 per FMC. Take-off and climb is fine. A few minutes after I'm passed to Washington Center, "MAX ALT FL19" pops up. After approximately 10 minutes, the a/c goes off course, banks past 35 degrees, and tries to descend. Joystick and throttle ignored. F1, F2, F3, F4 ignored. MCP alt ignored...until I dial in FL210. The keyboard and joystick/throttle control comes back. The A/C happily finishes the rest of the flight. Fully loaded 747x pax, identical behavior. (No comments from the pax about the barrel rolls, though). The only warnings are "BANK ANGLE". The route was made by FSX Flight Planner. The default 747 and one of the airbuses (sp?) flying the same route, no problems (no FMC, obviously). I have deleted the FSX.CFG, run the Flight1 registry fix, tested MS FSX FP routes, and hand-entered routes (from routefinder). No, unfortunately, this is not a halloween joke. It's been doing this for the last few weeks. Any suggestions (other than flying the 747X at FL190) would be most welcome. Thanks in advance,dan davisonPayware: PMDG 747X & MD-11; LevelD 767, FriendlyPanels FMC (not used) FS2Crew for default 747, 747X, and MD-11 (not used); FSBuild 2.3 (not used); TOPCAT (not used); Radar Contact V4 (not used).SIM: FSX+Acceleration on Win XP SP3 Affinity mode turned ON (allows FSX+Accel. to use multiple cores)VisionTek Radeon 3870 512 MB o/c to 800/1280 (stable for months)ASUS P5K MB, 2GB RAM, Q9450 processor o/c to 3.21 GHz, Saitek X52 throttle and joystick, 900W PSU, Antek 900 case.

[downscc 1,327]

This sounds like what happens in FSX when either a dialog box or the FS map is opened/closed. Usually will also trip A/T offline too... I can always clear it by pressing VNAV twice (it's not working even tho it says it is) that resets the sim back to normal. Could also be a third party app running with the sim... but the only one I use is ASX so I can't say.

[lensman 0]

Hi Dan,>This sounds like what happens in FSX when either a dialog box>or the FS map is opened/closed. Usually will also trip A/T>offline too... I can always clear it by pressing VNAV twice>(it's not working even tho it says it is) that resets the sim>back to normal. I don't have any third party apps loaded, and haven't looked at the map. I can't be sure about dialog boxes. But...yes, the A/T goes offline. I will try the push-vnav-twice method and see what happens. The VNAV light being on would contribute to my thinking the MCP is not responding.I'll let you know...dan