TK, Please release the Flight Model Editor

[+pcpilot 181]

We gots tons of great birds comin our way from a LOT of effort from a LOT of people with a LOT of other people anticipatin' those planes release... and not a one of them to my knowledge has an accurate flight model. They have to rely of FM's already done and in the game for entirely different aircraft, or do them the long handed way with a LOT of trial and error.

 

Come on TK, you wanted this sim to be open arch. So allow this work to be finished, and these people's hopes for this sim youve done to be fullfilled, I respectfully ask you to please release the FM editor, they need it now...

 

Lets consider this a petition, everyone sign it please and show your support for the efforts of TK in bringing us this sim and improving it, but also in the outstanding efforts of so many others to make it even better with GREAT, ACCURATE, QUALITY addons.

 

Special thanks to LVP, Gecko, WpnSgt, Boopidoo, Volksjager, Digital Overload, ArmourDave, BigBeer, USAFMTL, Fleet Defender, Pasko, Crab_02, Crisis, Swede, and many others. Thanks for your time and efforts, they are appreciated.

[+ext 52]

Pcpilot is right! There has been lots of hard work by many talented people who deserve many thanks for their hard work. I would not use the word petition but a request to TK. If you could release the editor or help in any way to compliment the work of others. This game is moving in leaps with all the new aircraft and campaigns ready to come out in the future. Any help would go a long way in making this game what we all thought it could be.

[Hedu VF-143 0]

I would hope this might be a route that TK considers. The guy making the F-105 has everything EXCEPT the flight model. When he posted this on another board, a person told him to just use the f-104 model. I thought what a complete waist of time. If I want to play ATF, I'll reinstall it, But to just use another planes flight model, especially one that isn't even close, is just ridicoulous. Why bother with flight models at all then?

 

No, the FMs must be released to the public.

[+Dave 2,322]

An FM editor is a must. Have you looked at those values in the data files? I think latin makes more sense.

[Hedu VF-143 0]

USAFMTL, I ahve not seen the data files yet as I am visiting the folks this weekend, and have never looked into it before. Is a special tool needed to look through them, or a hex editor?

 

I think that if there was anything that I would like to do to mod this sim, it would be flight models. I know that you open yourself to huge amounts of criticism, but I think you could say that is one thing that I particularly don't have trouble shrugging off. I have quite a bit of FM info, I collect flight manuals and am a Airplane book hound. If someone could set me in a right direction, I wouldn't mind tackling it.

[+Dave 2,322]

You can edit them with notepad but I don't know what the values mean.

[+Bunyap 0]

Wild Elmo (I think) posted this at simhq a few months ago. You have to know some hard core aerodynamics to make sense of it but it's better than nothing.

 

OK, here is a list of the various aerodynamic coefficients (the 3 or 4 letter variables

that start w/ the capital C) that are used in the flight model data files. I've also

listed a couple of other variables for the hell of it (Xac and DeltaStallAlpha), but

I'm going to limit this discussion primarily to the aerodynamic coefficients since this

is how the model generates all of the forces and moments on the airplane.

CL0 Lift coefficient at zero

angle of attack (AOA)

CLa Lift coefficient due to AOA

CD0 Zero-lift drag coefficient

CDL Drag coefficient due to lift

(induced drag effect)

Cmq Pitching moment due to pitch rate

(pitch damping)

Cmad Pitching moment due to AOA rate

(aero interaction between wings and horiz tail)

Cyb Side force due to sideslip

Cyp Side force due to roll rate

Cyr Side force due to yaw rate

Clb Roll moment due to sideslip

Clp Roll moment due to roll rate

(roll damping)

Clr Roll moment due to yaw rate

Cnb Yaw moment due to sideslip

Cnp Yaw moment due to roll rate

Cnr Yaw moment due to yaw rate

(yaw damping)

CLiftdc Lift due to control surface deflection

CDdc Drag due to control surface deflection

Cydc Side force due to control surface deflection

Cldc Roll moment due to control surface deflection

Cmdc Pitch moment due to control surface deflection

Cndc Yaw moment due to control surface deflection

DeltaStallAlpha Increase in max angle-of-attack before stall

Xac X-location of aerodynamic center

 

First thing to realize is that the coefficients are normalized by various dimensions of the

aircraft, so they don't represent the absolute value of the force or moment. So for example, for

Cnp, the actual yaw moment due to roll rate is found by mulitplying the coefficient by:

(Dynamic pressure * wing area * span^2) / (2*Velocity)

There is actually a very good reason for this, but I'm not going to go into it. The important

thing to understand is what force or moment is being generated by what.

 

Second thing to understand from a formatting standpoint, is that TK lists the coefficients first

by their 'base' values. Then he lists how the values will vary with either Mach # or angle-of-attack.

So for example, this is extracted from the data file for the F-4E in the section describing

the left outer wing (I've snipped out portions):

 

[LeftOuterWing]

.

.

.

CL0=0.0248

CLa=0.6532

CD0=0.0008

CDL=0.0037

Cmq=-0.2457

Cmad=-0.2229

Clb=0.0137

Clp=-0.0335

Clr=0.0296

Cnb=0.0424

Cnp=0.0011

Cnr=-0.0019

.

.

.

 

Shown above are the 'base' values that I described earlier. Following these are variation with Ma # and angle of attack

tables. Here's a typical table (for the F-4E left outer wing again):

 

.

.

.

CL0MachTableNumData=7

CL0MachTableDeltaX=0.40

CL0MachTableStartX=0.00

CL0MachTableData=0.976,1.000,1.087,1.212,0.858,0.692,0.577

.

.

.

 

The first row (CL0MachTableNumData) shows how many Ma # values the table varies over.

The second row indicates the delta in Ma # between data points.

The third row indicates the starting Ma # in the table.

The fourth row indicates the MULTIPLIER of the base CL0 value.

 

So for example at M=0 (starting takeoff for example), the multiplier of 0.976 is used with

the base value of 0.0248 (I'll let you multiply it out).

 

The same idea applies for the tables that vary with Alpha (angle-of-attack).

 

Finally, listed below is the right outer slat section for the F-4E and I'll go over these items

in detail (use the same basic idea for flaps, etc)

 

[RightOuterSlat]

SystemType=HIGHLIFT_DEVICE

CLiftdc=-0.0443

DeltaStallAlpha=6.00

AreaRatio=1.02

DeploymentMethod=AUTOMATIC_ANGLE_OF_ATTACK

Setting[1].Angle=30.0

Setting[1].DeployValue=13.8

Setting[1].RetractValue=8.7

MaxDeflection=30.0

MinDeflection=0.0

 

CLiftdc is the lift coefficient due to slat deployment (the value of -0.0443 seems questionable BTW).

DeltaStallAlpha is the change in maximum alpha before stall due to slat deployment (6 degrees in this case).

AreaRatio is the increase in wing area due to slat deployment.

DeploymentMethod indicates that the slats deploy automatically based upon the angle of attack.

Setting[1].Angle indicates that when deployed the slats are at 30 degree deflection.

Setting[1].DeployValue indicates that at 13.8 degrees the slats automatically deploy.

Setting[2].RetractValue indicates that at 8.7 degrees the slats automatically retract.

Max and min are self-explanatory

[+pcpilot 181]

:shock: WHOA! I guess I wont be modeling any Flight models...hehe.

 

You know, Im not even sure there is such a thing as a FM Editor. If there is, I hope TK will say so and release it for public use. If there isnt, then he sure had a chore doing the FM's for all the release aircraft. WOW!