Significantly over-weight GBU-12 bombs

[rinao0o]

Hi Zeus, thanks for your work on the bird!

 

For now the harrier module seems to be using the already existing triple GBU-12 loaded on BRU-42 weapons pylon, same as the one used on A10C. Problem is, ED got the bomb's weight completely wrong. The over-weighted bombs are really slowing this bird down and killing some fun factor!

 

Here is a file I snatched off the net showing the GBU12's actual weight, (MK82 Snakeye's weight is also shown in the pic, AFAIK the in-game snakeyes have their weight slightly lighter than the actual numbers)

 

So one GBU12 weights around 610lbs which is about 275 kg

 

In db_weapons_data.lua the bomb+rack loadout is defined as

{

CLSID = "BRU-42_3*GBU-12",

Picture = "GBU12.png",

wsTypeOfWeapon = {4, 5, 36, 38},

displayName = _("3 GBU-12"),

attribute = {4, 5, 32, 127},

Cx_pil = 0.002,

Count = 3,

Weight = 1230,

Elements = bru_42_ls("GBU-12")

},

Which means that currently in game, a BRU bomb rack + 3x GBU-12 = 1230 KG

 

Apparently something is wrong here, since 1 GBU-12 is 275 kg, multiply that by 3 you get 825, plus the adapter you get a weight of just about 900kg. So unless the adapter weights more than the bomb itself, there is no chance the overall weight could reach 1230kg.

 

Now, to make sure BRU-42 adapter isn't a heavy bulk of metal, here is the Navy's description for the BRU-42 rack.

 

The adapter assembly is a hollow, hexagonal aluminum extrusion that forms the main support for the rack assembly hardware. Attaching points on the adapter assembly provide 14-inch or 30-inch spacing of the suspension lugs, which allows installation on the various types of aircraft.

 

The adapter assembly houses the electronic control unit and cable assembly and provides for attachment of six or three individual ejector units. A nose-cone assembly and a tail-cone assembly enclose the ends of the adapter assembly for aerodynamic purposes.

 

#EDIT, mvsgas found the BRU-42 adapter weight to be 129lbs/~60kg from the Harrier Tac Manuel. That makes a triple GBU12 loadout 885 kg, comparing with the 1230 kg in-game weight, you get 690 kg of dead weight per each pair of triple GBU-12 loaded. That's equivalent to 20% internal fuel, or 2 heavy warhead Mav missiles.

 

Additionally, the double GBU12 loadouts also seem to have the wrong weight

 

AV8BNA_Weapons.lua

-- GBUs

declare_loadout(

{

category = CAT_BOMBS,

CLSID = "{BRU-42_2*GBU-12_LEFT}",

Picture = "GBU12.png",

wsTypeOfWeapon = {4, 5, 36, 38},

displayName = _("2 GBU-12"),

attribute = {4, 5, 32, 131},

Cx_pil = 0.00075,

Count = 2,

Weight = 60 + (362 * 2),

Elements = bru_42_ls_2("GBU-12",true),--left = true

}

)

 

declare_loadout(

{

category = CAT_BOMBS,

CLSID = "{BRU-42_2*GBU-12_RIGHT}",

Picture = "GBU12.png",

wsTypeOfWeapon = {4, 5, 36, 38},

displayName = _("2 GBU-12"),

attribute = {4, 5, 32, 131},

Cx_pil = 0.00075,

Count = 2,

Weight = 60 + (362 * 2),

Elements = bru_42_ls_2("GBU-12",false),--left = false

}

)

 

Here the bomb adapter is set at 60 kg which is correct, but every individual GBU-12 is set at 362 kg and that doesn't match any viable source. I believe the 362 first appeared in the ED's (totally unreliable)weapons database for the single station GBU-12, that means the single station GBU-12s also have the wrong weight! The only "source" I could find supporting the 362 is a random newspaper page, which doesn't really qualify as one.

 

Hopefully this can be fixed soon, thanks again for the module!

Edited December 14, 2017 by rinao0o

[mvsgas]

Here is more information on the GBU-12 and other weapons

https://docs.google.com/viewer?url=http%3A%2F%2Fcsef.ru%2Fmedia%2Farticles%2F4361%2F4361.pdf

 

Additionally, from A1-AV8BB-TAC-050, page1-83

[ATTACH]174241[/ATTACH]

Edited December 14, 2017 by mvsgas

[rinao0o]

Here is more information on the GBU-12 and other weapons

https://docs.google.com/viewer?url=http%3A%2F%2Fcsef.ru%2Fmedia%2Farticles%2F4361%2F4361.pdf

 

Additionally, from A1-AV8BB-TAC-050, page1-83

[ATTACH]174241[/ATTACH]

Nice pic, so adding all that up, the triple rack GBU-12 should weight 885 kg instead of 1230 we have in-game

 

Hopefully Razbam or ED can fix it soon, since I believe this is affecting not only the Harrier, but also birds like Mirage2000, A10C and everything else that can load GBU12 on it.

Edited December 14, 2017 by rinao0o

[al531246]

Good spot guys!

 

Hopefully BIGNEWY or one of other mods will see this and submit an internal ticket to ED.

[Zeus67]

NO problem. I can add my own 3 GBU-12 on ITER definition and fix this on the aircraft at least.

[al531246]

NO problem. I can add my own 3 GBU-12 on ITER definition and fix this on the aircraft at least.

 

I love this guy!

[BIGNEWY]

Hi guys

 

I will take a look.

 

https://www.globalsecurity.org/military/systems/munitions/gbu-12.htm

800lbs or 362.874kg

 

I will report and see what they say

 

edit looks like Zues is on it :)

 

NO problem. I can add my own 3 GBU-12 on ITER definition and fix this on the aircraft at least.

Edited December 14, 2017 by BIGNEWY

[Zeus67]

Just a heads up. Until further notice I can only use the same weight of a single bomb as indicated in ED's database. So I will correct it to 362 Kgs.

[CalinDee]

..and responsiveness like this is why I have ZERO issues with an early access purchase from these blokes!

Well done fellas.

 

oh, and great pickup OP! I wonder how far widespread the issue is (other aircraft wise), I guess across the gamut...

[Rlaxoxo]

So that's the reason why I can't VTO with 2 GBU-12's

[al531246]

EDIT

----------

Disregard my post, Chicken has cleared it up.

----------

 

I'm finding two figures for the weight of the GBU-12;

~600lb and ~800lb.

 

But I've found a website which seems to explain it.

The GBU weighs ~606 lb

and the warhead weighs ~192 lb

 

When we tot this up we get 798 lb which is very close to the 800 lb figure I'm seeing elsewhere.

 

It seems as tho 800 lb (362.874 kg) figure is a near enough estimate.

 

Sources;

https://www.globalsecurity.org/military/systems/munitions/gbu-12.htm

https://fas.org/man/dod-101/sys/smart/gbu-12.htm

http://www.designation-systems.net/dusrm/app5/paveway-2.html

http://www.deagel.com/Defensive-Weapons/GBU-12-Paveway-II_a001151002.aspx

https://docs.google.com/viewer?url=http%3A%2F%2Fcsef.ru%2Fmedia%2Farticles%2F4361%2F4361.pdf (PAGE 82)

Edited December 15, 2017 by al531246
GBU-12 actually weighs roughly 610 lbs, not 800 lb.

[ChickenSim]

The warhead itself is part of the GBU weight. A Guided Bomb Unit designation refers to the entire entity.

 

Please refer to the actual documentation and weapons files. Globalsecurity.org and fas.org are out to lunch on this one.

 

A GBU-12 weighs ~610 lbs, a GBU-16 weighs ~1110 lbs, a GBU-10 weighs ~2080 lbs, and minor variations you see on these numbers are because there are quite a few variants of computer control groups (CCGs) and an inexact amount of explosive fill.

[BIGNEWY]

The warhead itself is part of the GBU weight. A Guided Bomb Unit designation refers to the entire entity.

 

Please refer to the actual documentation and weapons files. Globalsecurity.org and fas.org are out to lunch on this one.

 

A GBU-12 weighs ~610 lbs, a GBU-16 weighs ~1110 lbs, a GBU-10 weighs ~2080 lbs, and minor variations you see on these numbers are because there are quite a few variants of computer control groups (CCGs) and an inexact amount of explosive fill.

 

Going to take a closer look at it today, I added the one from global security to show the varying weights reported from different sources.

 

It does look like the weight ED are using is off, I will make a report and see what they say.

 

EDIT: Report made #41456

 

I think the 275 kg (606 lb) is the best option

Edited December 15, 2017 by BIGNEWY