Current Max Take Off weight for AI

[speed-of-heat]

does anyone know the current max take off weight for AI from a cat shot, (as we know its bugged at the moment)?

[Ginsu80]

I haven’t had a crash yet with the AI on takeoffs, even with normal max take off weight but I know others have. The AI does pull stupid aoa, and come really close. I have also seen the AI get slow, 115kts or so and get stuck and fail to recover. Literally just fall out of the sky. Hoping it will be fixed this week as it’s caused me to be unable to work on t a campaign I’m building.

[Jenson]

In the supercarrier cold start mission, I've removed external tanks for all the AI aircrafts, and they are able to survive from crashing into the sea now, although still struggle. I didn't check the weight but I guess less than 43k lbs.  

[Stearmandriver]

The only ones I've ever seen survive have a light CAP loadout; even one bag plus any A/G stores is too much.  It basically makes carrier-based aircraft useless in a campaign. 

[speed-of-heat]

I just got 1 Bag, 4xJSOW (on the outer station) 2x9x , 2xAMMRAM and full internal fuel to go 

[Stearmandriver]

How?  I've seen literally dozens of aircraft loaded much lighter than that crash, with no successes at all!

[speed-of-heat]

I was flying oil in the water mission 8…

[Bunny Clark]

21 hours ago, Ginsu80 said:

Hoping it will be fixed this week as it’s caused me to be unable to work on t a campaign I’m building.

Unless there are features in Beta you absolutely need, I recommend working on Stable. Crap like this doesn't tend to make it to the Stable build nearly as often. 

[Stearmandriver]

7 hours ago, speed-of-heat said:

I was flying oil in the water mission 8…

Interesting.  Just curious, is that with the Stennis or Supercarrier?  I haven't thought to try the Stennis.

[speed-of-heat]

Super carrier

[Stearmandriver]

Huh.  Wonder if there's anything else that makes it work on that mission, or if it was some kind of fluke.  They sure won't go with that kind of loadout if you create a new mission. 

[Bunny Clark]

12 hours ago, Stearmandriver said:

Interesting.  Just curious, is that with the Stennis or Supercarrier?  I haven't thought to try the Stennis.

In my testing, it happens with both the Stennis and SC module ships. 

[Curly]

It looks like a change to lift coefficient in the simple flight model also increased the drag 6 times. Resulting in degraded performance.

 

In the last patch, the Cl max in Simple Flight Model for the F-18C was doubled. It went from 1.2 to 2.4. This also caused the drag to increase. In the SFM the drag is computed directly from the lift. The drag computation is given as:

 

Cx = Cx_0 + Cy^2*B2 +Cy^4*B4.

Where B2 and B4 are coefficients also defined in the SFM.  Cx is the drag and Cy is lift coefficient. 

 

  Previously Cl max was capped at 1.2.  it is now 2.4 This meant the drag at Cl max with flaps was

 

Cx = (Cx0 + Cx Flaps) + (Cy^2*B2) + (Cy^4* B4)

 

The old SFM F-18C, at mach .2 at CL max, 1.2, with the flaps down, had a drag coefficient of .584

 

Cx .584 = (Cx0 .0154)+ .(Cx Flaps. 23) + (Cy Max 1.2)^2*(B2 .134)  + (Cy max 1.2)^4* (B4 .056)

 

The new SFM at Cl max, 2.4 with flaps down has a drag coefficient of 2.905

Cx 2.905= (Cx0 .0154)+ .(Cx Flaps .23) + (Cy Max 2.4)^2*(B2 .134)  + (Cy max 2.4)^4* (B4 .056)

 

The previous version,  Cl max of the F-18C was capped at 1.2 it is now 2.4. Based on the the ratio of Cl to alpha as defined in the SFM; If the current SFM F-18C goes over 13.8 AOA with the flaps down, then it will have more drag than previous previous version of the SFM F-18C was capable of producing. 

 

[sigfan86]

2 hours ago, Curly said:

It looks like a change to lift coefficient in the simple flight model also increased the drag 6 times. Resulting in degraded performance.

 

In the last patch, the Cl max in Simple Flight Model for the F-18C was doubled. It went from 1.2 to 2.4. This also caused the drag to increase. In the SFM the drag is computed directly from the lift. The drag computation is given as:

 

Cx = Cx_0 + Cy^2*B2 +Cy^4*B4.

Where B2 and B4 are coefficients also defined in the SFM.  Cx is the drag and Cy is lift coefficient. 

 

  Previously Cl max was capped at 1.2.  it is now 2.4 This meant the drag at Cl max with flaps was

 

Cx = (Cx0 + Cx Flaps) + (Cy^2*B2) + (Cy^4* B4)

 

The old SFM F-18C, at mach .2 at CL max, 1.2, with the flaps down, had a drag coefficient of .584

 

Cx .584 = (Cx0 .0154)+ .(Cx Flaps. 23) + (Cy Max 1.2)^2*(B2 .134)  + (Cy max 1.2)^4* (B4 .056)

 

The new SFM at Cl max, 2.4 with flaps down has a drag coefficient of 2.905

Cx 2.905= (Cx0 .0154)+ .(Cx Flaps .23) + (Cy Max 2.4)^2*(B2 .134)  + (Cy max 2.4)^4* (B4 .056)

 

The previous version,  Cl max of the F-18C was capped at 1.2 it is now 2.4. Based on the the ratio of Cl to alpha as defined in the SFM; If the current SFM F-18C goes over 13.8 AOA with the flaps down, then it will have more drag than previous previous version of the SFM F-18C was capable of producing. 

 

Personally i find it ridiculous that paying customers have to dig in and figure out the math for the programmers, in my line of work,  mistakes like this cost programmers their jobs...

[Stearmandriver]

3 hours ago, Curly said:

It looks like a change to lift coefficient in the simple flight model also increased the drag 6 times. Resulting in degraded performance.

 

In the last patch, the Cl max in Simple Flight Model for the F-18C was doubled. It went from 1.2 to 2.4. This also caused the drag to increase. In the SFM the drag is computed directly from the lift. The drag computation is given as:

 

Cx = Cx_0 + Cy^2*B2 +Cy^4*B4.

Where B2 and B4 are coefficients also defined in the SFM.  Cx is the drag and Cy is lift coefficient. 

 

  Previously Cl max was capped at 1.2.  it is now 2.4 This meant the drag at Cl max with flaps was

 

Cx = (Cx0 + Cx Flaps) + (Cy^2*B2) + (Cy^4* B4)

 

The old SFM F-18C, at mach .2 at CL max, 1.2, with the flaps down, had a drag coefficient of .584

 

Cx .584 = (Cx0 .0154)+ .(Cx Flaps. 23) + (Cy Max 1.2)^2*(B2 .134)  + (Cy max 1.2)^4* (B4 .056)

 

The new SFM at Cl max, 2.4 with flaps down has a drag coefficient of 2.905

Cx 2.905= (Cx0 .0154)+ .(Cx Flaps .23) + (Cy Max 2.4)^2*(B2 .134)  + (Cy max 2.4)^4* (B4 .056)

 

The previous version,  Cl max of the F-18C was capped at 1.2 it is now 2.4. Based on the the ratio of Cl to alpha as defined in the SFM; If the current SFM F-18C goes over 13.8 AOA with the flaps down, then it will have more drag than previous previous version of the SFM F-18C was capable of producing. 

 

Excellent analysis! The question now is... can the current SFM be easily replaced by the old one (from the current stable build)?

[maxTRX]

6 hours ago, Curly said:

It looks like a change to lift coefficient in the simple flight model also increased the drag 6 times. Resulting in degraded performance.

 

In the last patch, the Cl max in Simple Flight Model for the F-18C was doubled. It went from 1.2 to 2.4. This also caused the drag to increase. In the SFM the drag is computed directly from the lift. The drag computation is given as:

 

Cx = Cx_0 + Cy^2*B2 +Cy^4*B4.

Where B2 and B4 are coefficients also defined in the SFM.  Cx is the drag and Cy is lift coefficient. 

 

  Previously Cl max was capped at 1.2.  it is now 2.4 This meant the drag at Cl max with flaps was

 

Cx = (Cx0 + Cx Flaps) + (Cy^2*B2) + (Cy^4* B4)

 

The old SFM F-18C, at mach .2 at CL max, 1.2, with the flaps down, had a drag coefficient of .584

 

Cx .584 = (Cx0 .0154)+ .(Cx Flaps. 23) + (Cy Max 1.2)^2*(B2 .134)  + (Cy max 1.2)^4* (B4 .056)

 

The new SFM at Cl max, 2.4 with flaps down has a drag coefficient of 2.905

Cx 2.905= (Cx0 .0154)+ .(Cx Flaps .23) + (Cy Max 2.4)^2*(B2 .134)  + (Cy max 2.4)^4* (B4 .056)

 

The previous version,  Cl max of the F-18C was capped at 1.2 it is now 2.4. Based on the the ratio of Cl to alpha as defined in the SFM; If the current SFM F-18C goes over 13.8 AOA with the flaps down, then it will have more drag than previous previous version of the SFM F-18C was capable of producing. 

 

 

Do all AI FA18C's use this model or only Lot 20s ?

[Nealius]

The big question is why was that even changed....I don't know of anything particularly broken with the previous AI flight model to warrant such a change. 

[Curly]

1 minute ago, Gripes323 said:

 

Do all AI FA18C's use this model or only Lot 20s ?

FA-18A.lua has the old Cl Max of 1.2

FA-18C.lua has the old Cl Max of 1.2

FA-18C_Hornet.lua has a Cl max of 2.4

[maxTRX]

13 minutes ago, Curly said:

FA-18A.lua has the old Cl Max of 1.2

FA-18C.lua has the old Cl Max of 1.2

FA-18C_Hornet.lua has a Cl max of 2.4

 

Copy, thanks.

[Dave317]

Can one be swapped with another for a short term fix? 

[frosen]

21 hours ago, Dave317 said:

Can one be swapped with another for a short term fix? 

+1

[Stearmandriver]

On 8/3/2021 at 9:12 PM, Curly said:

FA-18A.lua has the old Cl Max of 1.2

FA-18C.lua has the old Cl Max of 1.2

FA-18C_Hornet.lua has a Cl max of 2.4

Could you point me to the locations of these files?  I was going to try a quick replacement, but I'm only able to find two different FA-18C.lua files, and no FA-18A.lua or FA-18C_Hornet.lua at all.  Where are these located?

 

Thanks...

[Curly]

47 minutes ago, Stearmandriver said:

Could you point me to the locations of these files?  I was going to try a quick replacement, but I'm only able to find two different FA-18C.lua files, and no FA-18A.lua or FA-18C_Hornet.lua at all.  Where are these located?

 

Thanks...

They in the encrypted Database files.

https://github.com/Quaggles/dcs-lua-datamine/tree/master/_G/db/Units/Planes/Plane

[Stearmandriver]

Gotcha, thanks.  If encrypted, I guess there's no replacing or modifying the files though huh?