Loving the NGX!

[Kyle 0]

It took me a while, but I finally broke down to hand over $70 for this plane. I'm speechless. The detail and dynamics of this plane are simply outstanding. The HUGS display is a great feature as well. I do have a few questions though, having only owned this plane for a few hours. First, does the altitude hold (on the auto-pilot panel) override the VNAV path? I found a few times during a KLAX-KLAS run that the plane missed it's TOD and some other crossing restrictions; however, I have a feeling it's because the altitude hold restricted it from descending further. Second, does an accidental knock of the joystick override the LNAV. A few times the LNAV popped off, probably by me subconsciously pushing on my joystick.Third, does this plane have a "direct" function? For ex, ATC gives a short cut to a fix that isn't my next fix. Fourth, I've heard of a "descend now/present position" function. Where is this, and how is this applied?I'd appreciate any responses. Thanks and happy holidays.Kyle

[TheBFG 1]

I do have a few questions though, having only owned this plane for a few hours. First, does the altitude hold (on the auto-pilot panel) override the VNAV path? I found a few times during a KLAX-KLAS run that the plane missed it's TOD and some other crossing restrictions; however, I have a feeling it's because the altitude hold restricted it from descending further.

Hi! This isn't PMDG NGX specific, but all the same...This all assumes you're in VNAV. When you're approaching your TOD, you need to set your target altitude on the MCP. The aircraft won't depart its current altitude until it gets to the TOD. At that point it will retard the throttles and descend, but it won't descend below the altitude you've set on the MCP. You do however need to set the target altitude. If you're cruising at FL350 and reach your TOD, but the MCP is still set to 350, the aircraft will stay at 350. The idea would be to set your MCP to the next crossing altitude, say you need to cross the next fix at 9000 feet or above to join a STAR, set the MCP to 9000 feet and the aircraft will descend towards 9000 but won't go below. Then reduce the MCP altitude further when you've crossed that fix etc. until you're on final approach / have captured the glideslope, then you can set the MCP altitude to the missed approach altitude as we're no longer in VNAV. Now if you go around, the aircraft will climb towards the target altitude you set in the MCP and level off there, unless you increase the MCP value.

Second, does an accidental knock of the joystick override the LNAV. A few times the LNAV popped off, probably by me subconsciously pushing on my joystick.

Does the autopilot disconnect, or just LNAV? The autopilot will disconnect when you put in enough control input. LNAV shouldn't disengage because of control inputs.

Third, does this plane have a "direct" function? For ex, ATC gives a short cut to a fix that isn't my next fix.

On the FMC, go to the legs page. Select the fix you want to fly to, then select the first (top) fix. The first one will be moved up to the top, replacing it.

Fourth, I've heard of a "descend now/present position" function. Where is this, and how is this applied?

There's a little button on the MCP next to the altitude selector labelled "ALT INTV". If you press that before you get to your TOD, the aircraft will descend at 1000fpm (with a bit of power) until it crosses it's planned VNAV descent path, and then continue on that steeper path at a higher rate of descent with engines at idle. Remember this will of course only work if you've set the MCP altitude lower than cruise altitude, as discussed in point 1.

[OzWhitey 3,353]

Descend now is on the des page of the fmc.And if deflect the joystick laterally enough in lnav, your pfd readout will change from lnav to csw.

[Kyle 0]

Thanks guys, that helps a lot. One more question. On final approach, or shortly before that, how can I take over the speed from the FMC speed. I would like to keep the VNAV (controlling the g/s) and LNAV (controlling the loc) but fine tune the speed near the final approach segment. Any way to do this?Kyle

[Spook 96]

switch off autothrottle and manually ajust..But these kind of questions ARE answered in the manual.Vnav and Lnav controlling the loc and g/s is a new on me..or am i missing something?

[ckeddf 4]

Thanks guys, that helps a lot.One more question. On final approach, or shortly before that, how can I take over the speed from the FMC speed. I would like to keep the VNAV (controlling the g/s) and LNAV (controlling the loc) but fine tune the speed near the final approach segment. Any way to do this?Kyle

Use speed intervention (SPD INTV button to the right of the IAS knob).

[TheBFG 1]

I would like to keep the VNAV (controlling the g/s) and LNAV (controlling the loc) but fine tune the speed near the final approach segment. Any way to do this?

Just to clarify: VNAV and LNAV have nothing to do with the ILS. They should be long gone by this point, with the localizer and glideslope guiding you to the runway (LOC/GS instead of LNAV/VNAV)

[RYR738 9]

Thanks guys, that helps a lot.One more question. On final approach, or shortly before that, how can I take over the speed from the FMC speed. I would like to keep the VNAV (controlling the g/s) and LNAV (controlling the loc) but fine tune the speed near the final approach segment. Any way to do this?Kyle

As the post directly above this one says !.........VNAV does not control the glideslope and LNAV does not control the localizer.If you use VNAV for your descent, VOR/LOC will replace LNAV as the roll mode at localizer capture ( in VOR/LOC or APP mode ) andGS will replace VNAV PATH as the pitch mode at glideslope capture. ( in APP mode of course ! )The APP mode is the only AFDS mode that can calculate/control Thrust, Pitch and Roll. ( it also allows engagement of both autopilots )Just use the speed knob to lower your speed to the different flap speeds. ( you will see these in the DESC page of the CDU. They are actually flap speed restrictions. )or just do it visually by extending the flaps and dialling down the speed until the speed bug is over the green flap number.VNAV will be doing this for you automatically until the glideslope is captured.Don't forget to enter your landing REF speed in the CDU Approach page. ( usually flaps 30 )Normal procedure is to land at REF speed + 5 knots. ( you will see this landing speed reference in the DESC page too )A visual way to do this is to park the speed bug on top (not over it) of the green REF number. That gives you REF + 5.Fred.

[Kyle 0]

As the post directly above this one says !.........VNAV does not control the glideslope and LNAV does not control the localizer.If you use VNAV for your descent, VOR/LOC will replace LNAV as the roll mode at localizer capture ( in VOR/LOC or APP mode ) andGS will replace VNAV PATH as the pitch mode at glideslope capture. ( in APP mode of course ! )The APP mode is the only AFDS mode that can calculate/control Thrust, Pitch and Roll. ( it also allows engagement of both autopilots )Just use the speed knob to lower your speed to the different flap speeds. ( you will see these in the DESC page of the CDU. They are actually flap speed restrictions. )or just do it visually by extending the flaps and dialling down the speed until the speed bug is over the green flap number.VNAV will be doing this for you automatically until the glideslope is captured.Don't forget to enter your landing REF speed in the CDU Approach page. ( usually flaps 30 )Normal procedure is to land at REF speed + 5 knots. ( you will see this landing speed reference in the DESC page too )A visual way to do this is to park the speed bug on top (not over it) of the green REF number. That gives you REF + 5.Fred.

Hey,Sorry for the earlier post; yep I found the LOC/GS buttons .Just flew an ILS into LAX on VATSIM SWA478 at night. The HUD is awesome!Thanks all for the replies.Kyle

[Fabo 213]

Just a side-note, to add to Freds answer, if you are flying ILS approach, you should leave the control to APP mode, but it is in fact possible to fly an approach in VNAV/LNAV overlay. In that case you would most likely use Speed Intervention function to set speed, while VNAV would control the glidepath and LNAV will control the lateral trajectory.

[Kyle 0]

OK, ran into another question. I was flying the BXK2 out of KPHX and after takeoff I enabled LNAV. The plane began to make a slight left turn (as it should) but then the LNAV jerked off and I was left with nothing. Any ideas? For some reason, on that same departure, I was unable to enable VNAV as well.

[Kyle 0]

I figured it out. My joystick is quite off-centered (I've owned it for a while) and when I release my hold on it, LNAV/HDG sel take it as a control input.