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Jack C

777 wont climb. Negative AoA

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I searched a bit for this answer and couldn't find anything that was specifically like my prob. SO normal kind of load. GW of about 560K. Took off and leveled at 4K for the departure. Then cleared FL 360, clicked CLB DIR and the poor bugger wouldn't climb or accelerate. Stayed about 235 kts. Tried CLB1....nothing. Tried CLB...nothing. The weird thing is I actually have about a 2-3 negative angle of attack on the AoA indicator and if you go to spot view you can see the plane is actually pointed downwards BUT I am getting about a 200 FT/min climb. So Neg AoA but still slightly climbing. Physics tells me no way. So I went tot he Pax Load page and clicked empty flight. Sped up a wee bit not much. Climbed a bit better but barely. Weather was AS16 but nothing unusual in the weather. Was using p3d. Anyone have a clue? Thanks

Jack Colwill

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Std Atmosphere. Its nothing like that. Besides if the temp made that much of a difference in this case, I wouldn't have even got off the runway

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check pg 996 of the fcom 2 manual

 

CLB DIR does not initiate a climb. it just removes altitude restrictions from the flight plan between your altitude and the crz alt.

 

CLB and CLB1 are different derated thrust settigns and don't affect altitude either..

 

to initiate the climb you need to click the altitude knob after dialing in the altitude..(similar to the alt inv button on the 737)! that is assuming you are in VNAV mode anyway and have programmed the FMC with the cruise setup and all.

 

maybe this is something around the source of your issues?? it's a little unclear without knowing for sure what autopilot mode you are using etc

 

good luck!

cheers

-andy crosby

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check pg 996 of the fcom 2 manual

 

CLB DIR does not initiate a climb. it just removes altitude restrictions from the flight plan between your altitude and the crz alt.

 

CLB and CLB1 are different derated thrust settigns and don't affect altitude either..

 

to initiate the climb you need to click the altitude knob after dialing in the altitude..(similar to the alt inv button on the 737)! that is assuming you are in VNAV mode anyway and have programmed the FMC with the cruise setup and all.

 

maybe this is something around the source of your issues?? it's a little unclear without knowing for sure what autopilot mode you are using etc

 

good luck!

cheers

-andy crosby

Hey Andy. Thx for the input. I fly the 67 IRL and we use the CLB DCT. LSK coming out of gatwick every now and then. If I recall correctly it initiates the climb to whatever you have in the MCP. And remove all altitude restrictions. I just thought it would work the same in the 77.

 

Hey Kyle. I'm almost 100% sure it's not the axis but I'll check again. I took a screen of it. Either way a negative angle of attack should not be associated with any climb at all but it is in this case.

Thx

Jack Colwill

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Hey Kyle. I'm almost 100% sure it's not the axis but I'll check again. I took a screen of it. Either way a negative angle of attack should not be associated with any climb at all but it is in this case.

 

The negative AoA thing and climb issues is the hallmark of FSUIPC flaps axes. Literal calling card of sorts. A quick run through google will give you quite a number of hits.

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Kyle, thank you. It WAS the axis. I dont quite get it but whatever. If my flaps are up they are up. Didnt think the axis thing in fsuipc would make a diff. I was really starting to scratch my head because I ran the exact same scenario in FSX and it worked fine. Went back to p3d and problem existed. I reset my flap axis in fsuipc and the thing started climbing right away. Thanks Kyle. Back to the big pig

Jack Colwill 

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Kyle, thank you. It WAS the axis. I dont quite get it but whatever. If my flaps are up they are up. Didnt think the axis thing in fsuipc would make a diff. I was really starting to scratch my head because I ran the exact same scenario in FSX and it worked fine. Went back to p3d and problem existed. I reset my flap axis in fsuipc and the thing started climbing right away. Thanks Kyle. Back to the big pig

Jack Colwill 

 

Welcome!

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I also experienced  this strange issue on my last flight. I have flown this bird many times, never experienced this before. Engines at full power, clean wing and gear configuration. Only at 40% max zfw and 20% fuel. I could not climb past 20,000 feet and only 210 knots. I should be climbing like a rocket. Also PFD showing a slight down angle.

 

Came here looking if anyone else had this problem, and found this thread. Never would have thought it was the Axis in FSUIPC.  I reset the Axis and everything is back to normal.

 

Thanks Kyle

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A few years ago in FSX  I had something similar to this when flying the PMDG 737... I struggled with it for a long time  until I figured out the issue was in the FSUIPC.ini file

 

When I deleted the FSUIPC.ini (after backup) and  restarted FSX and the problem disspeared. .so I knew it was one of the FSUIPC entry.. I then put back the offending FSUIPC.ini file and then via  long process of elimination (remove first half of the file) load FSX to see if the issue was there or not, and then doing a binary search... got to the exact line.... one entry in the FSUIPC was causing it (a stealth flap extension)

 

Start by deleting your FSUIPC.ini (after backup). if that doesn't solve the issue then you can look elsewhere.

 

Edited to add:


Never mind,  you solved the issue..  :smile:

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