Uncommanded Pitch Up On Runway

[Z09SS 21]

Why do some planes start pulling their noses up as you get close to take-off speed and others don't?

 

Can it be fixed?

 

It's a real irritant when landing because you need to put nose down stick to correct it and keep from lifting off again.

[yubba 70]

 it is called lift and all the planes have a different center of gravity,, you can change the flight model in the game options

from easy normal and hard,, you should watch some youtube film of the aircraft you are flying,,, if you want to fly a pain in the butt plane try the B-58 Hustler and then check out the film

[Z09SS 21]

I've watched lots and lots of F-15 footage and the nose doesn't come up until the control surfaces move is why I complain.

[MigBuster 2,884]

Something TK added to the FMs after 2008 IIRC.............thought it was to make it easier for less experienced to get off the ground even on hard FM.

 

 

You need to change the FM basically to get rid of.

[yubba 70]

I sorta recall, Janes F-15 would almost fly it's self at take off thought it common that it would nose up,, the F-15E is a masterpiece here,, at the moment I'm flying carrier ops with the A-7D

Edited August 23, 2015 by yubba

[Happy308 186]

I do not  like the auto pitch up and take off feature myself.

At the moment I'am flying the mig 21 pmf / bis.

And I fixed it by changing  the "DownwashAlphaTableNumData"  value on both stabilators.

The default value is 37 and I changed it to 10

 

At 300 KMs the nose pitches up slightly but the plane never takes of by it self.

 

I have not yet tried It on other planes so far

 

I hope this is of some help to you.

[+baffmeister 1,205]

Happy308, here is another table you could try adjusting to get the desired results. It may reduce the turn capability a bit at very low speeds but I don't think it's very significant. I consider it as a "stab trim for take off" setting.

 

From the stock MiG-21Bis FM:

 

[LeftStab]
ParentComponentName=Fuselage
ModelNodeName=
ShowFromCockpit=TRUE
DetachWhenDestroyed=TRUE
DamageRating=DISABLED
MassFraction=0.013
HasAeroCoefficients=TRUE
LiftSurface=TRUE
CL0=-0.0192
CLa=0.2833
CD0=0.0005
CDL=0.0001
Cmq=-4.8380
Cmad=-0.4951
Cyb=-0.0723
Clp=-0.0042
Cnb=0.0443
CL0MachTableNumData=21
CL0MachTableDeltaX=0.10
CL0MachTableStartX=0.00
CL0MachTableData=1.497,[1.549,1.616,1.578,]1.000,0.728,0.580,0.494,0.447,0.394,0.231,0.283,0.297,0.283,0.264,0.245,0.231,0.218,0.207,0.199,0.190.....Try reducing the three numbers in brackets for both stabs.

 

Reducing the three numbers in brackets will reduce the download on the tail over the mach 0.10 to mach 0.30 range. With a bit of tweaking you should be able to get the behavior you're looking for.

 

At one point I was playing around with that auto-rotation effect but ultimately, like you, I found it quite annoying and unnatural during the landing phase. It was difficult to stick a nice landing. I think in RL neutral stab trim settings for take off and landing are probably the norm. Not sure to what extent ThirdWire is using that effect to generate more realistic rotation/take-off speeds for the AI, you might want to watch a few of your AI wing men take off to see if there are any issues.

Edited December 2, 2015 by baffmeister