Few questions about PMDG 737-800

[Fabo 213]

Best thing to do is forget LNAV/VNAV. Setup a saved flight and just practice the T/O procedures.

I beg to differ. VNAV is set up exactly so that you follow proper take-off procedure, if you go after the bars right after rotation.

You'll want the lower speed to reduce the turn radius, which means flaps may have to stay out longer. Or let's say I'm flying the local pattern and want more visibility over the nose than a lower body angle is needed. Only two thing can help you here.

This is not a VNAV problem, but a VNAV mismanagement problem. Properly set and properly flown, VNAV can do any of this safely and precisely.It is hard to say why Nicholas is having problems without seeing what he does in the climbout and how much does the speed actually decay...

[coa1117 53]

I had the OP's problem with speed bleed on t/o with my first few NGX flights last summer. As I recall it had to do with the A/T Manual Override setting in the Aircraft Equipment options in the FMC. Setting this to "Never" eliminated the problem. Look at the PMDG-737NGX-Introduction.pdf document, near the bottom of page 56 for a description of the options for this setting.

[SteveAull 22]

I beg to differ. VNAV is set up exactly so that you follow proper take-off procedure, if you go after the bars right after rotation.This is not a VNAV problem, but a VNAV mismanagement problem. Properly set and properly flown, VNAV can do any of this safely and precisely.It is hard to say why Nicholas is having problems without seeing what he does in the climbout and how much does the speed actually decay...

I never said VNAV would not follow proper take-off procedure. I said that not every airport will have a procedure where VNAV can be used immediatly after takeoff. As far as the tight turn is concerned again if you have a coded departure for this great....if not VNAV will want to accelerate to cleanup speed, increasing turn radias.Most the time I'll use VNAV but again it's not the be all to end all for every airport or situation. Last time I checked there are pilots in the cockpit.I sould have mentioned to him, to go to an airport that has a nice departure where VNAV can be armed on the ground and watch to see how it does it! Edited February 20, 2012 by SteveAull

[Fabo 213]

Please, bring any such procedure to my attention, I have never seen one.

[Spin737 102]

... not every airport will have a procedure where VNAV can be used immediatly after takeoff.

Hmmm. I don't think that's the case. It's not airport specific.

[SteveAull 22]

Ok guys I was just giving him some suggestions. Don't want to get in a contest with you.....Peace.....

[RYR738 9]

I agree with Matt. Some screenshots are needed !Fred.

[martin-w 3,235]

I had the OP's problem with speed bleed on t/o with my first few NGX flights last summer. As I recall it had to do with the A/T Manual Override setting in the Aircraft Equipment options in the FMC. Setting this to "Never" eliminated the problem. Look at the PMDG-737NGX-Introduction.pdf document, near the bottom of page 56 for a description of the options for this setting.

Sounds to me like the above could indeed be the issue!

I beg to differ. It is the small cross to the left and slightly above the COURSE indicator window. When you hover over it, the mouse changes to a hand. When you click it, TO/GA lights up in the green on the PFD. So that is not the problem.Martin-which tutorial are you referring to? I searched for the one by Tom Risager (is that the one you mean?) and cannot find it anywhere. All the links are dead. I would be grateful if you could direct me.

Regarding the tutorial, look in your start menu...Re TOGA click spot, I refer to the VC, perhaps you are using the 2D, perhaps it's in a different location in the 2D.Anyway, it's all in the manuals. Edited February 21, 2012 by martin-w

[nicholas49 0]

coa1117: thanks for that. I've looked in the Introduction document you referenced. However, I don't appear to have the option to change the 'PMDG Settings' in my FMC. I would post a screenshot but I can't make that work either. Sigh.martin-w: what do you mean by 'start menu'? Please can you be more specific. I am very willing to watch a good tutorial if you can direct me to it! Is this a tutorial that can be run in FS2004 (like the standard FS2004 flying lessons) or is it web-based etc.?On the VNAV/LNAV point, I agree with the SteveAull that this is not the priority for me at the moment.Two more observations:1) I have also noticed that the aircraft is not always capable of rotating at the rotation speed calculated by the FMC. Again, something not right there me thinks.2) Sometimes, on rotation, the throttles power back by about 20%. The PFD changes to 'MCP Speed' from 'TO/GA' Again, you can imagine what this does for the climb-out performance.

Edited February 21, 2012 by nicholas49

[kevinh 409]

I beg to differ. It is the small cross to the left and slightly above the COURSE indicator window. When you hover over it, the mouse changes to a hand. When you click it, TO/GA lights up in the green on the PFD. So that is not the problem.Martin-which tutorial are you referring to? I searched for the one by Tom Risager (is that the one you mean?) and cannot find it anywhere. All the links are dead. I would be grateful if you could direct me.

On the NGX there is no clickspot where you say there is, VC or 2D. The TOGA clickspot in the VC is to the left of the FD switch, below the course window. In the 2D panel it's the screw head at the bottom left the autopilot MCP panel. Are you sure you are running the NGX and not the "classic" PMDG 737NG in FS9 or even a rival NG simulation?

coa1117: thanks for that. I've looked in the Introduction document you referenced. However, I don't appear to have the option to change the 'PMDG Settings' in my FMC. I would post a screenshot but I can't make that work either. Sigh.

The PMDG SETUP menu is found if you press the MENU key on the CDU. If you don't see it you definitely aren't running the PMDG NGX.

martin-w: what do you mean by 'start menu'? Please can you be more specific. I am very willing to watch a good tutorial if you can direct me to it! Is this a tutorial that can be run in FS2004 (like the standard FS2004 flying lessons) or is it web-based etc.?

"Start menu" is the Windows start menu. You'll find the PMDG tutorial at:All programsPMDG SimulationsPMDG 737NGX

On the VNAV/LNAV point, I agree with the SteveAull that this is not the priority for me at the moment.

Wise move.

Two more observations:1) I have also noticed that the aircraft is not always capable of rotating at the rotation speed calculated by the FMC. Again, something not right there me thinks.2) Sometimes, on rotation, the throttles power back by about 20%. The PFD changes to 'MCP Speed' from 'TO/GA' Again, you can imagine what this does for the climb-out performance.

1. This will happen if you haven't set the stab trim correctly for your weight and CG.2. If TOGA is not properly set the autoflight system may well revert to a default state as the aircraft lifts off. If you haven't set V2 in the MCP it will try and maintain whatever speed is in the window, probably 100 knots, causing the throttles to retard.

You have to upload screenshots to the forum, you can't simply cut and past a shortcut from your PC. Select the image button in the posting menu and follow the instructions. Edited February 21, 2012 by kevinh

[nicholas49 0]

I am not using PMDG 737NGX! I am using PMDG 737NG from Precision Manuals Development Group (according to the Installation Notes). I am sorry if I didn't make this clear earlier - I thought the fact I referenced PMDG 738 was sufficient.The TOGA clickspot is definitely at the top-left-hand corner of the MCP in 2D. Let's leave that point now though please.Can you direct me to a tutorial for the aircraft I have?RE: screenshots. I did copy and paste the image into this box, but it only shows the file root (and you can't delete that either).

Edited February 21, 2012 by nicholas49

[kevinh 409]

I am not using PMDG 737NGX! I am using PMDG 737NG from Precision Manuals Development Group (according to the Installation Notes). I am sorry if I didn't make this clear earlier - I thought the fact I referenced PMDG 738 was sufficient.The TOGA clickspot is definitely at the top-left-hand corner of the MCP in 2D. Let's leave that point now though please.Can you direct me to a tutorial for the aircraft I have?RE: screenshots. I did copy and paste the image into this box, but it only shows the file root (and you can't delete that either).

Ahh, that explains the confusion. There is a seperate forum here for the PMDG NG. If you post in the NGX forum, people will assume you are using the NGX. TOGA was activated by the upper left screw on the MCP in the original PMDG 737NG, so now that all makes sense.I don't think there was a PMDG tutorial for the 737NG, but there is a document in the 737NG manuals called Flight Techniques which describes takeoff procedures in general terms. Regardless of tutorials, the key thing is to get in the habit of setting up the basics from memory:Ensure the FMC CDU is fully pre-flighted (all square box prompts in the initialisation pages filled with correct data). So you will enter a route (at least an origin and destination airport), aircraft weight (gross wt or zero fuel wt), cost index (pick a number between 10 and 30), a value for reserve fuel (I use 3 tonnes). cruise flight level, and takeoff flap. Ensure you have selected a departure runway so the FMC can calculate the takeoff speeds for you.FD switches onA/T switch armedSet V2 in the speed window (this is a must)Set the initial altitude in the altitude window.Set stab trim to the correct value.Set flaps to the takeoff position as entered into the CDUAdvance throttles and then select TOGAObviously the rest of the cockpit needs to be properly configured but the items above are the ones necessary for the simulation to work properly on takeoff.For screenshots forget what I said about the image button, that is for images already on line. Copying and Pasting the image there won't work. You need to use the Attach Files area below the posting window, browse to your image and select it for uploading. Edited February 21, 2012 by kevinh

[nicholas49 0]

Thank you kevinh for the very helpful post.I'm really sorry about posting in the wrong forum - I thought I checked really carefully beforehand. My mistake.I have followed your instructions* to the letter and have attached a screenshot of the aircraft after take-off when 'things start to go wrong'. I am showing the FMC PERF. INC. page in case that is relevant (but I think is all programmed correctly). The speed has just started to decay before I hit pause. And as you'll see, I'm not even quite flying at the pitch commanded by the FD. Can you offer any more insight into what I am doing wrong?* With one exception: I do not know how to set the stabiliser trim. I see it on the throttle control (though can't seem to make changes there). How do I adjust it and how do I know what to adjust it to?

Edited February 21, 2012 by nicholas49

[Spin737 102]

Thank you kevinh for the very helpful post.I'm really sorry about posting in the wrong forum - I thought I checked really carefully beforehand. My mistake.I have followed your instructions* to the letter and have attached a screenshot of the aircraft after take-off when 'things start to go wrong'. I am showing the FMC PERF. INC. page in case that is relevant (but I think is all programmed correctly). The speed has just started to decay before I hit pause. And as you'll see, I'm not even quite flying at the pitch commanded by the FD. Can you offer any more insight into what I am doing wrong?* With one exception: I do not know how to set the stabiliser trim. I see it on the throttle control (though can't seem to make changes there). How do I adjust it and how do I know what to adjust it to?

Your speed is decreasing appropriately because you're too fast. Go back a few steps.

[kevinh 409]

Thank you kevinh for the very helpful post.I'm really sorry about posting in the wrong forum - I thought I checked really carefully beforehand. My mistake.I have followed your instructions* to the letter and have attached a screenshot of the aircraft after take-off when 'things start to go wrong'. I am showing the FMC PERF. INC. page in case that is relevant (but I think is all programmed correctly). The speed has just started to decay before I hit pause. And as you'll see, I'm not even quite flying at the pitch commanded by the FD. Can you offer any more insight into what I am doing wrong?* With one exception: I do not know how to set the stabiliser trim. I see it on the throttle control (though can't seem to make changes there). How do I adjust it and how do I know what to adjust it to?

As Matt said above you are too fast (182 knots, the command bug is still at V2, 138). The FD is commanding nose up to decrease speed too. You probably rotated late due to the trim being out of position. Because you aren't using VNAV you must manually increase the commanded speed when you get to acceleration height (1500 feet above ground by default). Set 250 knots and retract flaps progressively as speed approaches the next green number on the ASI scale. In your screenshot you should already have selected Flap 1 as the next green marker is a 1 and airspeed is only just below it. When you feel confident enough to try using VNAV the speed bug will move automatically (the speed window will be blank), but you still have to retract flap manually as you accelerate.The FMC TAKEOFF REF Page 1 shows you current CG in %MAC and the recommended takeoff TRIM position in units. Set the stab trim to the value displayed there. See page 8-39 in the manuals. Chapter 8 is dedicated to the FMC and has a very detailed description of FMC pre-flight from page 8-14 onwards. I don't recall whether the stab trim has any hot spots to drive it on the panel, but you can always use the default FS9 trim nose up/down keys or map those to suitable buttons on your controller.If you use the correct trim value the NG will rotate properly at Vr and will already be in trim for flight at V2+20. Edited February 21, 2012 by kevinh