boeingflir

777 Climb Performance

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I am having a perplexing problem. During departure the aircraft just kinda dies performance wise around 3400'. This happens with no altitude restrictions and 12000' or 310 in the altitude window. I have the thrust reduction altitude at 1500' and acceleration altitude at 3000' for a close in noise abatement departure procedure. The climb is normal until acceleration altitude (I'm in Climb 1 at 1500'). At 3000' I go to flaps 5, after a 15 degree flap TO at 550 thousand lbs. and it just won't accelerate the way it should and rate of climb goes down to 500'/min. It will get to 0 flap maneuvering speed (about 230Kts) after an inordinate amount of time and distance. When I get to 0 flap man spd, bring the flaps up, it's in THR REF, Roll is LNAV and Pitch is VNAV SPD as it should be. Thrust is Climb 1 at about 89%. It does the same thing at Max Climb so that isn't the issue. It will not accelerate above about 230 Kts and won't climb. By accident I discovered that opening FSUIPC and them canceling it gets rid of the issue and the aircraft starts accelerating (thrust remains the same) to 250Kts and then starts climbing at 3000+/FPM. I have checked for conflicts between FSUIPC and FSX EXTENSIVELY. I have looked at it from the external view and the flaps are physically up and indicated up. No speed or altitude restrictions in the FMC. Everything else in this simulation works perfectly except, occasionally, on a coupled ILS to 9L at Heathrow I will get a continuous GPWS pull up terrain warning. The terrain is flat on final.

Any thoughts, suggestions, or solutions? Any help is appreciated.

Thanks you in advance.

Bruce Jacobs 

 

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Hi,

Your fsuipc profile is causing the issue. It is an issue that can be seen often. The fix is to delete your fsuipc profile and build a new one from scratch.
If you have a separate file for the profile, delete it (back it up before delete in case it would not be the cause, but very likely). 

If you don't have a separate file but the profile is in the fsuipc.ini, then you have to delete that file (back it up also in case) and build a new profile.

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8 hours ago, boeingflir said:

By accident I discovered that opening FSUIPC and them canceling it gets rid of the issue and the aircraft starts accelerating (thrust remains the same) to 250Kts and then starts climbing at 3000+/FPM. I have checked for conflicts between FSUIPC and FSX EXTENSIVELY. I have looked at it from the external view and the flaps are physically up and indicated up.

Yep. FSUIPC is nice, but it also gets in the way when not properly configured. You've simply run into one of the long-known issues with FSUIPC and complex aircraft.

8 hours ago, boeingflir said:

Everything else in this simulation works perfectly except, occasionally, on a coupled ILS to 9L at Heathrow I will get a continuous GPWS pull up terrain warning. The terrain is flat on final.

<sim root>\PMDG\ - Look in these folders for an APT_RWYS.dat (or similarly-named file) and delete it so that it can rebuild.

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Thanks to both of you. I'll get under the hood soon. I know the introduction makes the case for not using FSUIPC but rather programing everything through FSX. Is that true?

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23 minutes ago, boeingflir said:

Thanks to both of you. I'll get under the hood soon. I know the introduction makes the case for not using FSUIPC but rather programing everything through FSX. Is that true?

I believe it's just the flaps.  The flaps look like they are up but the sim sees them as down.  That's why the aircraft won't climb or accelerate well.   Try deleting any assignment of the flaps through FSUIPC before you completely eliminate FSUIPC, and see if that fixes the problem.

Mike

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I'll check the flaps first. It is logical since it does seem to happen around 1 degree flap maneuvering speed which would be just the LEDs, but the brains of the system won't let it go above that speed if it thinks they're down. Even the old 757/767 did that. Hard to believe those are "old." Of course the 727 you could keep accelerating until you tore the LEDs and trailing edge flaps off the airframe. Those were the days.

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No joy. I deleted all flap setting from FSUIPC and programed flaps through FSX options. worked fine mechanically, but still stalls at 0 flap man. speed. That's on all versions, all departures.

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Bruce, you have not acknowledged that you removed fsuipc.ini from the modules folder.  You can move it to your desktop for temporary safe keeping.  Deleting settings from within FSUIPC is no joy as far as this problem goes.

Don't try to make sense of it man, just try it.  This problem is well known and has very specific symptoms which you are reporting.

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46 minutes ago, boeingflir said:

No joy. I deleted all flap setting from FSUIPC and programed flaps through FSX options. worked fine mechanically, but still stalls at 0 flap man. speed. That's on all versions, all departures.

Hi Bruce,

If you have a lot of profiles for different aircraft and it would be a hassle to redo all of them, first try deleting just the profile for the PMDG 777.  If it would be easy to redo your existing profiles, just follow the advice of Romain and Dan: remove FSUIPC.ini from the modules folder to somewhere outside of FSX and let it rebuild.

41 minutes ago, downscc said:

Bruce, you have not acknowledged that you removed fsuipc.ini from the modules folder.  You can move it to your desktop for temporary safe keeping.  Deleting settings from within FSUIPC is no joy as far as this problem goes.

Don't try to make sense of it man, just try it.  This problem is well known and has very specific symptoms which you are reporting.

I am just trying to help him avoid the hassle of redoing a lot of work if he has multiple profiles.

Bruce, BTW, the file that Kyle suggested you delete to eliminate false GPWS warnings is in FSX/PMDG/NavData and is named ARPT_RWY.dat  It is not part of the Airac data and will rebuild the next time you load the 777 (or 747 QOT II). 

Mike

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OK, I have not gone into FSUIPC yet. I thought that I'd make one last desperate attempt to solve it without digging in. I am not too conversant with the bowels of the PC as in my real life I'm a mac user, but I have an expert on hand. I have all my settings so getting my few a/c back up will not be too hard. I have 737NG, the 777 and a Level D 767 all set aircraft specific and I'm working with the 777 now. I know what I'm doing with FSUIPC in programing the a/c. Thanks again for all the help and I'll give a progress report. I don't have time to work on it right now.😎 I thank everyone for their input.

Bruce Jacobs

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5 minutes ago, boeingflir said:

OK, I have not gone into FSUIPC yet. I thought that I'd make one last desperate attempt to solve it without digging in. I am not too conversant with the bowels of the PC as in my real life I'm a mac user, but I have an expert on hand. I have all my settings so getting my few a/c back up will not be too hard. I have 737NG, the 777 and a Level D 767 all set aircraft specific and I'm working with the 777 now. I know what I'm doing with FSUIPC in programing the a/c. Thanks again for all the help and I'll give a progress report. I don't have time to work on it right now.😎 I thank everyone for their input.

Hi Bruce,

You have no need to start messing with "the bowels of the PC" to fix either the FSUIPC problem or the GPWS problem!  You are scaring me!

Just remove the 777 profile and see if that fixes the climb/speed problem.  If not, remove FSUIPC.ini and let it rebuild.

If you are not familiar with how to find and delete a file, ask your friend, but this is not a complex operation.

For the GPWS problem just delete the file ARPT_RNWY.dat  in FSX/PMDG/NavData. 

Mike

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And to avoid further hassle to people who have fsuipc profiles for different aircrafts, I would strongly recommend to configure fsuipc to make separate files for each profile so that if one gets corrupted you'll have to delete just that separate file and not the fsuipc.ini with all the profiles to redo.

The process is well explain in the fsuipc docs and quite simple. It is basically just to replace a figure at one line of the fsuipc.

I have never had any issues with the profiles but since the issue seems to occur often by the number of occurences on that forum, I did it anyway.

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5 minutes ago, Budbud said:

And to avoid further hassle to people who have fsuipc profiles for different aircrafts, I would strongly recommend to configure fsuipc to make separate files for each profile so that if one gets corrupted you'll have to delete just that separate file and not the fsuipc.ini with all the profiles to redo.

The process is well explain in the fsuipc docs and quite simple. It is basically just to replace a figure at one line of the fsuipc.

I have never had any issues with the profiles but since the issue seems to occur often by the number of occurences on that forum, I did it anyway.

I couldn't agree more!

Mike

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Thanks again. Unfortunately I have to leave town before I can get the guy who knows what he's doing over. I'll give an update in a couple of weeks. 

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