Low speed on climb out

[RDG41 1]

I have a problem with my 747 and prepar v4. I create all my flights with FSC and have been for a long time with no issues. On climb out, engines are set for climb thrust, but the plane just can't get enough speed to climb up to crz. It just seems to get to about 6-7000 ft and sit there, climbing very slow with the engines running at climb rate , then leveling to try to gain speed, but never gets there. Starting to wonder if it might be FSUIPC. Going to try tonight with it disabled.

I'm using win10, fsuipc5 with ORBX scenery, no payware airports installed yet.

Anyone have any ideas on what's going on? Thanks.

[JRBarrett 3,070]

Any chance you may have forgotten to retract the gear or flaps? I ask, because I have done that myself!

Are you using a weather injection program of any kind? If so, check the outside air temperature.

Are you importing your FSC flight plan directly into the FMS? Possibly something is corrupting your PERF data, or aircraft loading.

 

 

[RDG41 1]

Hi Jim,

No, gear was up, and flaps were up as well. In fact , I retracted the flaps even though I hadn't reached the proper retract speed(it just wouldn't get there).

Yes, I'm using active sky. I will check the air temp , thanks.

Yes, I'm importing my flight plan directly into the FMC. It's always been good. I should just try manually inputting one just to eliminate the possibility that it's causing any issues.

I tend to be a lazy pilot. I import my route and just let the FMC do its thing. I've always gotten away with that up until now.

[downscc 1,327]

1 hour ago, RDG41 said:

but the plane just can't get enough speed to climb up to crz. It just seems to get to about 6-7000 ft and sit there, climbing very slow with the engines running at climb rate , then leveling to try to gain speed, but never gets there.

Please be more concise with your problem description.  Can't get enough speed means nothing, are you going 180 kts or 240 kts? Where are you on the flap retraction schedule? Are you using VNAV or what flight mode are you using? What about pitch, is that normal or does it seem to not have enough pitch up?

About 80% of the posts here about initial climb issues are fixed when the FSUIPC.ini file is moved to the desktop.

[paradoxbox 13]

Make sure your autothrottle is on and in the correct mode, and that you are not hitting a speed restriction you or your flight planning software have programmed into the route. Common speed restrictions are around 250 knots, but sometimes they're lower depending on the plan you're flying. This could cause the engines to spool down, and if there's an altitude restriction then that would just mean you're capped out at that speed and alt until you tell the airplane to do otherwise.

Try switching to SPD mode and set a VS and altitude target in the windows (press the knobs in to set the value into the autopilot) and see how the engines respond to that. If they do not spool up to match the requested vertical speed you must have some kind of FSUIPC or other control issue.

[RDG41 1]

ok...tested with FSUIPC and without. No weather, clear skies and it appears that yes FSUIPC is affecting this. Just to show the differences in flight I took screen shots at the same stage of each flight. Now I also experienced a loss of thrust ref on take off on one flight ,so I'm not sure if I have some kind of hardware spike happening sometimes. But regardless,both flights from the screen shot were normal on take off. Hopefully this link works. Thank you all for responding. Let me know if there is anything else you would like me to try or do.

https://www.dropbox.com/sh/a4pob1jijd74nhi/AABX1Y_8UKLl2q52EeGhDjlXa?dl=0

 

[downscc 1,327]

Yeah, that 5 deg nose pitch down is most definitely one of the signatures of a corrupt FSUIPC.ini file.  The Queen is never nose down 5 deg, she is royalty and flies with her chin up and proud.

[BlueStar 323]

5 minutes ago, downscc said:

Yeah, that 5 deg nose pitch down is most definitely one of the signatures of a corrupt FSUIPC.ini file.  The Queen is never nose down 5 deg, she is royalty and flies with her chin up and proud.

Dan,

What in the FSUIPC.ini would cause the aircraft to be 5 degrees nose down?

blaustern  

[RDG41 1]

I'm going to try a fresh install of FSUIPC and see if things change.

[skelsey 765]

1 hour ago, Bluestar said:

What in the FSUIPC.ini would cause the aircraft to be 5 degrees nose down?

I believe it is an issue with assigning the flaps to a joystick axis (rather than keys or buttons) in FSUIPC. The same issue arises with the 777 and perhaps other models, as I recall.

[Mike777 163]

2 hours ago, RDG41 said:

ok...tested with FSUIPC and without. No weather, clear skies and it appears that yes FSUIPC is affecting this. Just to show the differences in flight I took screen shots at the same stage of each flight.

 

 

6 hours ago, downscc said:

About 80% of the posts here about initial climb issues are fixed when the FSUIPC.ini file is moved to the desktop.

There's a known, issue, at least with the 777, that if the flaps are configured through FSUIPC they may appear to be up but the Sim sees them as down.

Mike

 

[RDG41 1]

I reinstalled the plane and FSUIPC and have no issues now. Climb rate is correct along with speed. Now I don't have any assignments yet. On the previous install, I had assigned flaps and speed brakes to my throttle. I've never had them assigned before so maybe this was the issue?(Skelsey) If something changes, I will repost.

Thanks.

[Budbud 227]

7 minutes ago, RDG41 said:

On the previous install, I had assigned flaps and speed brakes to my throttle. I've never had them assigned before so maybe this was the issue?

Hi,

The issue is definitely related to fsuipc and always solved by deleting the profile and making a fresh one.
But it does not systematically occurs when you assign axis to the flaps on fsuipc. I have been using fsuipc with a axis assigned to the flaps in the profile for as long as I can remember (at least since the release of the NGX for fsx) and successfully with the NGX, the T7 and the 747 and never got that sort of issues.

I don't know if it is the particular way to configure the flaps axis or if it is just random from one system to another or whatever... 

Now you know how to fix it if it occurs again (though no need to reinstall the aircraft), you may try to reconfigure an axis to the flaps in fsuipc and see if it happens again.

[RDG41 1]

Thanks Romain for that helpful information. I just wanted to add that the reason I reinstalled the plane was because I was getting some odd behavior as well. I would lose my thrust ref on takeoff sometimes just before V1(without FSUIPC). I'm not sure if that's a hardware spike issue or not. But I remember having the same issue a while ago and reinstalling the plane solved it.

[downscc 1,327]

2 hours ago, RDG41 said:

But I remember having the same issue a while ago and reinstalling the plane solved it.

Temporarily at least... but as a rule removing and reinstalling will create more problems that it solves. Try using a logical approach to identifying the problem.  The loss of THR REF  during takeoff is most likely throttle movement either the controller or the cat bumped the controller.  I can't even think of anything else that could cause it off the top of my head.