wing_incidence and AOA

[dmaher]

I’ve read a few posts that say the ‘wing_incidence‘ angle in the aircraft.cfg is just for reference and has no effect.

It certainly doesn’t seem to work.
In level flight my AOA matches the Pitch Indicator at cruise speed. (0 deg for both)
Trying a bunch of wing_incidence values form -5 to +5 I saw no change.
I think if it was working this is one place it would show up…unless I’m missing something.

My question is…in table 404 CL vs AOA do we have to adjust all figures to account for this missing wing incidence.

tbl404AOA = knownAOA - (wingIncident)

So if I want to stall at 16deg AOA, and I have +2deg wing incident, my graph should use 14deg AOA?
Basically translate all graph values left/right according to a +/ - wing incident.

Or is there another parameter to set to account for this angle.



Danny

[Milton Shupe]

Which sim?

After FS8, the wing incidence and twist is not used in FS9. Not sure about FSX.

Yes, you need to adjust all of 404, and you need to change stall angle alarm in 1101. You can also set min induced drag AoA there.

[dmaher]

Thanks Milton,

I should have mentioned I’m using FSX.

I’ve adjusted table 404 Cl_vs_AOA by trial and error.
The lift and drag performance is getting close to what I’d hope.
But I’m trying to double check some things before I move ahead.


It was suggested to put the stall at 16deg AOA.
But I was really torn about how to account for the wing incidence.
My hunch is the wing incidence should be ignored...in tble. 404

My question isn’t worded that well, but I’m pretty sure I’ve classically confused AOA with pitch.

I think, the wing’s CL for a given AOA isn’t influenced by how the fuselage happens to be attached.

[Ivan]

Hello DMaher,

I usta work with a fellow named David Maher. You wouldn't happen to know anything about a Sailfish, would you?

I typically work with Combat Flight Simulator 1, so I am not certain what I have to write affects you or not. My current project is a Curtiss P-40C Tomahawk (Hawk 81). I HAD about 2 degrees incidence in the wing when I started. I noticed that from an external view, the plane flew noticeably nose down. I adjusted it to Zero degrees and the plane still flew a touch nose down but less so. As for Table 404, I try to make them look very much like the graphs for the particular airfoil the plane actually had. As for a setting that says "Stall Angle" or something of that type, I believe it is the angle at which the stall warning comes on. It doesn't affect the actual stall angle at all. For a FW 190A I was working on a couple years back, I set the angle down to about 13 degrees even though the actual stall happened at around 15 degrees. This was done to provide more warning for a very harsh stall. This was to replace the "seat of the pants" built-in G Meter that flight sim pilots don't have.

- Ivan.