777, S-turns FSUIPC etc

[777Swede 0]

Hi,

 

I have serahced this forum for hours and also Google on it but I haven't found a solution. I have also tried YouTube. No where do I find an answer...

 

 

1.

I did a video of the isses below with Camtasia that illustrates very clearly what I'm talking about. Please suggest to me what to do with this video if it can help to demonstate the problem and perhaps lead to a solution. YouTube?

 

 

2.

777 latest version.

W7-64, 16 GB i7 3.0 Mhz  2 x Samsung 1TB SSD.

 

 

2.

Fresh W7 install. Nothing else on this machine than W7-64 and FSX (sp1 and 2) and PMDG 777 and PMDG 737.

 

 

3.

I'll try to make as brief a description as possible of the series of the issues I have, as I somehow feel they may be connected and depend on something I haven't set up ok. Judging by the massively imprtessive PMDG 777 I doubt anything is wrong with the simcraft itself - but rather my setup or something.

 

a)

If the route involves a long turn ( like almost 180 degrees etc) it seems the 777 first banks a little too steep so that it is "inside" the turn. Then as it comes closer to where it should fly level again it is now outside the turn and has to turn back towards the track when it leaves the turn. When it turns back this means an S-turn is unavoidable of course... But it does not turn back all the way and properly gets back on track again... instead it sort of leans towards the track and hope time will solve the problem... For minutes sometimes... and then it's back on track... Sometimes this can take 10 minutes... Plane in a constant 2-3 degree bank... (no winds or anything btw). There seem to be variations to the problems I have described - the basic descriptin I guess is that it doesn't turn the way it should. And it doesn't follow the track as it should.

 

b)

Flying SIDs and STARs with many turns left and right and maybe 5-10 waypoints instead of doing the turns like it should and fly straight on track in between the whole SID or STAR becomes a myriad of turning, turning, turning (lots of S-turns)  and if the distances between waypoints aren't long enough it can enter into a new scenarios that further adds to the confusion...

 

 

c)

I have frame rates that are typically 23-45 fps. Everything looks good and smooth otherwise.

 

 

d)

I have followed PMDG's instructions by the letter in terms of install and FSX prefs etc.

 

 

e)

I read on AVSIM about FSUIPC. So I purchased that and downloaded it. Hoping that it should be the solution to the above problems. But I'm not really sure exactly how to set it up - if indeed FSUIPC is the solution fro me here. Is it? Is FSUIPC the solution? (If so - why isn't it included in the 777? Could have saved me many hours......

 

 

f)

Flying the 737 I see sort of the same problems but not to the extent of the 777. The 737 is a little firmer and while it also "leans" for miutes sometimes, actual turns are made with more "discipline" if you like...

 

g) And onther strange phenomenon: On the 777 the magenta line is sometimes drawn on the screen describing the most amazing geometrical shapes... Often when approacing such a butterfly like shape it vanishes and becoms a simple straight line again. I'm mentioning it in case it has some diagnostic value...

 

 

Apart from above the PMDG 777 is fantastic and the looks and accuracy and detail etc. makes for a truly impressive experience... Both interior flight deck and exterior is very well made!

 

If I could only make it follow the flight plan and stick to the magenta line instead of deviating from this and do the turns well I would be so happy!

 

g) Oh yes, one more thing: right before it's supposed to turn, there's a "spike" or stutter and the turn is started a bit abruptly. This could take a way the smooth magic flow of the flying experince. Is this perhaps connected with the issues I've already described above?

 

 

Thanks in advance for your advice

Lars

 

 

[BeechPapa 32]

Pull up on the stick more when you're in a turn. It's not bank angle that turns a plane, it's the lift generated by the wings that does it. Banking only angles the lift vector laterally... It's up to the wings to do the rest, and generate the lift required for the turn.

 

This graphic helps explains the forces involved in a turn:

[777Swede 0]

Hi BeechPapa, thanks for your reply. It is very true what you say but it doesn't address the issues I'm decribing in my post/question or relates to the 777 problems I'm having...  Happy Holidays to you!

[downscc 1,327]

Lars, first let me welcome you to the PMDG forum. Please note that PMDG request full names in our posts here, you can create a signature block to make that chore easy.

 

As far as the B777 following the magenta line:  Nope.  In most cases is appears that it is following the line but in fact that is a coincidence. You have found several good examples of when she seems to turn inside or outside the magenta line then has to correct to get on the desired track. This is normal behavior. Of course I remarked on it during beta testing and there were some minor tweaks made during that period but to the best of my knowledge (I am not a B777 rated pilot) the simulation is behaving the same as the aircraft.  My trick to get rid of the track corrections is to reset the next waypoint on the LEGS page such that a new path is set from current position, this is the easiest trick I have found. I am sure there are others.

 

FSUIPC is not required or necessary for the operation of the PMDG B777

 

When you see the ND displaying odd shaped track lines that then snap into proper position, you are witnessing the FMS doing calculations and path predictions before your eyes. Normal stuff.

 

No comparisons can be made between the B737 and the B777 systems. There are too many differences, including the vintage of the systems designed for the airframe.  The B737 NG is newer than the B777.

[777Swede 0]

Thanks for the reply. Happy Holidays!

[Ken.Pascoe 1]

One reason the aircraft (autopilot engaged, LNAV engaged) doesn't follow the magenta line is speed. If the SID/STAR is predicated on a specific airspeed and you're not in managed speed (VNAV SPD Climb or VNAV PATH Cruise/Descent) with the MCP speed window closed - often times the performance of the turn dictates an inability to comply with the magenta line. Radius of turn is dictated by TAS (Wind & GS plays a role too) and if you're doing 250 KIAS but the FMC was predicting 170 knots at that point - you'll turn outside the magenta line. Bank angle is usually limited at between 25 and 35 degrees and while LNAV will turn the aircraft less steeply to comply with a turn radius - it can't turn more steeply than these internal speed/configuration based turn limits, no matter what the FMC is calling for.

 

That said, there are also some specific instances where the aircraft does indeed deviate from the magenta line while in LNAV. Again usually performance related where the LEGS page waypoint requirements exceed the turning ability of the aircraft.

 

However ... in my experience on the aircraft and simulator - those time are few a far between, well known when you've flown a route a few times, and something to watch out for. As a "child of the magenta" - being off that line in LNAV is a peculiar feeling ...

[BeechPapa 32]

Hi BeechPapa, thanks for your reply. It is very true what you say but it doesn't address the issues I'm decribing in my post/question or relates to the 777 problems I'm having...  Happy Holidays to you!

 

Sorry, didn't realize you meant autopilot specifically. As others have mentioned, it will deviate from the magenta "ideal" based on a number of factors. In cases where the magenta line begins to dance around or the turn is unnecessarily tight, I like to do a double tap on the first waypoint in the legs page and then execute. It's a quick fix, and will re-route the magenta line according to your current position, smoothing out whatever kinks there were in the calculated path.    

[Ken.Pascoe 1]

Sorry, didn't realize you meant autopilot specifically. As others have mentioned, it will deviate from the magenta "ideal" based on a number of factors. In cases where the magenta line begins to dance around or the turn is unnecessarily tight, I like to do a double tap on the first waypoint in the legs page and then execute. It's a quick fix, and will re-route the magenta line according to your current position, smoothing out whatever kinks there were in the calculated path.

 

That's a good technique and one used often in the aircraft. Another use for it is to force a re-calculation of VNAV descent path when you get high or low (due ATC, winds or other factors).

[BeechPapa 32]

That's a good technique and one used often in the aircraft. Another use for it is to force a re-calculation of VNAV descent path when you get high or low (due ATC, winds or other factors).

 

Sweet! Amazing what kind of habits one can pick up in the sim (good and bad) that apply to real thing. I hadn't even thought of using it for VNAV. I didn't put two and two together. The days of me muttering about ATC putting me off path might be over. Thanks. 

[Wanthuyr Filho 83]

Is there any known solution for this "crazy" magenta track of 777 PMDG? It's good most of the time, but in specific procedures such as the beginning of a SID, or a VOR approach procedure, it draws really strange things at the ND. I am aware of the real system and I know it doesn't occur in there.