PMDG 737 wont follow autopilot LNAV or VNAV

[W4TT3RS]

Hello! Having recently purchased the PMDG737-800 i have encountered a problem where after setting up the FMC and getting airborne the aircraft does not follow LNAV or VNAV once climbing, for example say the aircraft has to turn right to its next way point, the magenta cross hairs on the PFD will turn to the correct direction however the actual aircraft will not turn right, at that time both LNAV and VNAV are switched on. Any help would be thanked! ;)

[luke]

Do you have autopilot turned on? On the far right of the MCP there is a button labeled "CMD A" press that button and it should work.

[★Macman★]

It works so long as you Aligned 3 NAVS and rid any Discontinuities. For AP to be able to work you must have the Pitch in a capable ready state. Make TRIM 5.8 for TAKEOFFS and then hit LNAV & VNAV after 300ft then hit AP at 1400ft but already have made FLAPS 1 by that stage. You might also need to correct TRIM but aim for 15 to 20 Degrees Pitch.

VNAV can be made either by AP or even using it's Refs with AP OFF and flying Manually. It can be really slow Speeds though to use at STARS & SIDS so for the Sim I suggest not using that. FLC is best to Climb whilst you set AutoThrust 250kts under 10,000ft then 310kts above. Descend with VS and set Pitch to -2500 and follow ATC. Set Speed 290kts using Speed Brakes until at 13,000ft to be at 275kts, then 250kts under 10,000ft , then follow ATC Suggested Speed. If you try VNAV it will certainly be very slow and not make all the Altitudes on the FP unless you carefully edited them all to Real Charts. It's that crap. Great Plane though.

[Schmegg]

Publicado originalmente por ★Macman★:

It works so long as you Aligned 3 NAVS and rid any Discontinuities. For AP to be able to work you must have the Pitch in a capable ready state. Make TRIM 5.8 for TAKEOFFS and then hit LNAV & VNAV after 300ft then hit AP at 1400ft but already have made FLAPS 1 by that stage. You might also need to correct TRIM but aim for 15 to 20 Degrees Pitch.

VNAV can be made either by AP or even using it's Refs with AP OFF and flying Manually. It can be really slow Speeds though to use at STARS & SIDS so for the Sim I suggest not using that. FLC is best to Climb whilst you set AutoThrust 250kts under 10,000ft then 310kts above. Descend with VS and set Pitch to -2500 and follow ATC. Set Speed 290kts using Speed Brakes until at 13,000ft to be at 275kts, then 250kts under 10,000ft , then follow ATC Suggested Speed. If you try VNAV it will certainly be very slow and not make all the Altitudes on the FP unless you carefully edited them all to Real Charts. It's that crap. Great Plane though.

VNAV works perfectly. You're using it wrong. Too hard to go through it all here though.

[★Macman★]

VNAV selects Speeds way too slow not to be boring is all. Not using it wrong. It will tell me to drop 8000ft to 3000ft within impossible time. PAX would be throwing up and I 'd be having to struggle to lose Speed as that would often mean greater than -2500ft/min. I do not like it. Trusting ATC is a far better method I found as it conflicts with it very badly to make bad Alt changes.
VNAV used to work well for the A320. Really not sure how it's doing right now as I totally hate that Plane for being dull.

[Schmegg]

Again - VNAV works perfectly fine on the PMDG 737's. Sounds to me like you are not properly programming the FMC. When all is done correctly, the aircraft operates within normal limits and does not do anything 'vomit inducing'. VNAV follows real world nav data speed and altitude restrictions very well. Fair enough if you don't like that, but saying VNAV doesn't work well because it doesn't work the way you would prefer is making false accusations.

[W4TT3RS]

Publicado originalmente por Schmegg:

Publicado originalmente por ★Macman★:

It works so long as you Aligned 3 NAVS and rid any Discontinuities. For AP to be able to work you must have the Pitch in a capable ready state. Make TRIM 5.8 for TAKEOFFS and then hit LNAV & VNAV after 300ft then hit AP at 1400ft but already have made FLAPS 1 by that stage. You might also need to correct TRIM but aim for 15 to 20 Degrees Pitch.

VNAV can be made either by AP or even using it's Refs with AP OFF and flying Manually. It can be really slow Speeds though to use at STARS & SIDS so for the Sim I suggest not using that. FLC is best to Climb whilst you set AutoThrust 250kts under 10,000ft then 310kts above. Descend with VS and set Pitch to -2500 and follow ATC. Set Speed 290kts using Speed Brakes until at 13,000ft to be at 275kts, then 250kts under 10,000ft , then follow ATC Suggested Speed. If you try VNAV it will certainly be very slow and not make all the Altitudes on the FP unless you carefully edited them all to Real Charts. It's that crap. Great Plane though.

VNAV works perfectly. You're using it wrong. Too hard to go through it all here though.

Having flown the all variants of the PMDG 737 family available to us flight simmers over the years I have accumulated over 2000 hours on that family of aircraft alone, and over 9000 hours across fsx and p3d, the issue is resolved and seemed to be down to the MSFS2020 ai pilot settings, having disabled all pilot assistance settings the aircraft now follows the flight directions and proper FMC inputs. If you are not going to be respectful then there is no point in commenting.

[Schmegg]

Publicado originalmente por W4TT3RS:

Publicado originalmente por Schmegg:

VNAV works perfectly. You're using it wrong. Too hard to go through it all here though.

Having flown the all variants of the PMDG 737 family available to us flight simmers over the years I have accumulated over 2000 hours on that family of aircraft alone, and over 9000 hours across fsx and p3d, the issue is resolved and seemed to be down to the MSFS2020 ai pilot settings, having disabled all pilot assistance settings the aircraft now follows the flight directions and proper FMC inputs. If you are not going to be respectful then there is no point in commenting.

I wasn't addressing you. Please pay attention to whom I was directing my comment.

Anyway - glad you've worked it out. Good to know the assists were the problem.