Helicopter armament performance.

[Sundowner 11]

Since the helicopters are still very much a work in progress, I don't want to go here into the flight mechanics, and animations, which need work on their own. What I want to write about is the armament performance taking the AH-9 as an example.

1. The armament controls:

Since 2001, we had to choose either a weapon, or its mode of use, switching back and forward. This is not how it's done on the Little Birds, which are very specific in that regard. Most armed helicopters, like for an early example - armed variants of UH-1s - had armament activated with a single cyclic switch, and its mode or type, was chosen using a control box located on the pedestal console. OH-6A and later AH-6 (with exception of MELB which is more complex and modular) were a bit different, the armament system was integrated in such a way, that the weapons were activated by separate switches - when armed, always ready to use. The miniguns under two detent trigger switch (first detent - 2000rpm, second - 4000rpm), and the rocket launchers under thumb switch.

What I suggest is allowing to assign buttons, and keys to fire separate weapons without the need to cycle trough them. So far (A2, OA, TKOH) I was using a macro that cycled the weapons depending what I did with my joystick, but it's not very reliable.

2. Rockets dispersion:

FFARs are very finicky in real life. They weathervane into the relative wind upon launch and during flight - the Vietnam-era Mk.4/Mk.40 were especially inaccurate. HYDRA 70 are a bit better with more spin, and different design of the fins, yet still the kill ratio was improved by the cluster munition warheads, and not superior aerodynamics.

In the game, rockets fly straight into the point where we aimed them, their rocket motors burning all the way to the impact. In reality FFAR engines burn for less than seconds, and after that it's ballistics. We need changed FFAR launch effect, and more dispersion - if weathervaning can't be implemented, then at least take into account some of the momentum from moving helicopter - if you shoot a FFAR moving sideways, it should go waaay off to the direction you are flying - same with ascend and descend off-boresight.

3. Miniguns dispersion:

M134 have dispersion of 6mrads, which basically means, that at a range of 450 meters (1500ft), 80% of rounds will impact in a circle of 2,7m (9ft) diameter, and its a normal (Gaussian) distribution - so the closer to aiming point - the more likely that space will get a bullet. Right now, the miniguns spray wildely, and the safest place for enemy to be, is inside the aiming reticle - pretty much no matter the range. There's something fundamentally wrong here.

[MaxiM_PL 1]

What I suggest is allowing to assign buttons, and keys to fire separate weapons without the need to cycle trough them. So far (A2, OA, TKOH) I was using a macro that cycled the weapons depending what I did with my joystick, but it's not very reliable.

Very much this! I have all those buttons on my joystick for a reason. It's something I've been missing as well, yet it's such a basic functionality. As for the hyper-real dispersion and all that... I don't really mind it. I mean it's ArmA, not TOH2 ;)

[Sundowner 11]

This is all up for discussion. I don't really require ultra-realistic weapons behavior. I don't require the miniguns to have exactly that numbers of dispersion (actually in the old days you had sets of rings that would change the dispersion of that weapon), but make it consistent with laws of physics - put most of the rounds where I'm aiming at, not around my target. I would also accept a statement that those FFARs are inertialy guided, though the motor burn needs tweaking, and they need at least look as if they're obeying the laws of physics, they're not photon torpedoes you know.

[Iroquois Pliskin 0]

3. Miniguns dispersion:

M134 have dispersion of 6mrads, which basically means, that at a range of 450 meters (1500ft), 80% of rounds will impact in a circle of 2,7m (9ft) diameter, and its a normal (Gaussian) distribution - so the closer to aiming point - the more likely that space will get a bullet. Right now, the miniguns spray wildely, and the safest place for enemy to be, is inside the aiming reticle - pretty much no matter the range. There's something fundamentally wrong here.

+1

M134 grouping accuracy on the AH6s has always been a problem in ArmA/II. :( A3A is a bit better in this department, though more testing is needed. /fires up editor

[scajolly 14]

Might I add, not to derail, that when you discuss controlling weapons we also make arming them an actual action. Safeties are not a thing for vehicles in Arma, hardly even for infantry, and it's very problematic from the standpoint of those that play missions where the shots can be few and far between. ACE solved this neatly, but not perfectly.

[max power 21]

I did some research and was able to find the results of a test on rocket performance a while back for our mod. Unless someone has stomped my config changes, it seems like the final dispersion of rockets fired from a helicopter is 0.68 degrees or 0.012 radians.

[Sundowner 11]

Umm... the Hydra 70 with mk.66 motor in reality have 29mrads of dispersion, and that's 50% of rounds (for some reason DARPA is measuring differently for guns, rockets and bombs).

[SmallBlackSheep 0]

All very good points! I didn't know about the FFARs.

Regarding #1, please vote on this related Feedback ticket: http://feedback.arma3.com/view.php?id=4497

[Zorg_DK 10]

Maybe it's just my sh1t aim, but I found it impossible to hit anything with the AH9 minigun.

[Maio 293]

Maybe it's just my sh1t aim, but I found it impossible to hit anything with the AH9 minigun.

Try slowing down and firing in a small Z pattern ( this applies when engaging single "human" targets)

As for the OP. I very much agree with point 2.

[Zorg_DK 10]

Try slowing down and firing in a small Z pattern ( this applies when engaging single "human" targets)

As for the OP. I very much agree with point 2.

Ok, I'll try that.

[-=seany=- 5]

I agree with most points. I to would be great to have separate gun and rockets buttons.

About the FFARs, my guess is in the era this is supposed to be set, they would even more accurate than they currently are and GPS guided :D . I get what you mean though, with current day FFAR. DCS A10 gives a good impression of their "accuracy".

Actually thinking of DCS A10, would an AH6 etc have CCIP aimed rockets?

Edited March 13, 2013 by -=seany=-

[Sundowner 11]

About the FFARs, my guess is in the era this is supposed to be set, they would even more accurate than they currently are and GPS guided :D . I get what you mean though, with current day FFAR. DCS A10 gives a good impression of their "accuracy".

Actually thinking of DCS A10, would an AH6 etc have CCIP aimed rockets?

DCS Warthog is pretty good when it comes to FFAR accuracy, although it's lacking in representation of their lethality, or even actual warhead effect. Plus bare in mind, that FFARs launched from planes are more accurate, because of the relative wind being always close to being parallel to boresight. Launching FFARs from helicopters is problematic, the rocket have to accelerate from none, or low initial speed - therefore the velocity at the end of 1.07 second motor burn is lower - therefore any side wind have more impact on the flight path. Firing from hover, results in rocked going initially through area of downwash, resulting in pitch-up, making the rounds go on different trajectory, than in translational lift speed, or above. Any side-slip movement is also exaggerated by the rocket aerodynamic design.

It's not easy to compute impact point from this type of unguided weaponry - the most accurate, being the Apache gunship, utilizing, laser range finder, ballistic computer, and (something that is unique for its design) launcher elevation servos inside pylons - even with all of this, it's still very far from pinpoint accuracy. Even with all those advanced systems, Apache will get you accuracy resulting in 50% of fired rockets, landing in 26m circle, at 1000m. If you're engaging a target, you need a pinpoint accuracy - like a tank - the chances of hitting it are actually very slim. That's why the HYDRA 70 came with not only new engine, but a line of cluster warheads, like the M261, that have 9 grenades, that are released after a time delay.

So, a CCIP option on a small, "bare bone" helicopter like the AH-9? Yes, you could put ballistic computer, and turret with rangefinder plus Helmet Mounted Sight, but you won't get much out of it, you will still shoot roughly into an area. If I would be managing such Arma 3 project, I would rather concentrate on different warhead options for the rockets, than the aiming system. For example 160th SOAR Littlebirds, have no aids for aiming the miniguns and rockets - although the OH-6A had a sight for the minigun - you use those weapons "by feel".

[JestersDead 2]

The rate of fire on the miniguns are way off as well. I did a simple test last night. I took off in the AH-9 with the standard 5000 round load. I fired a 10 second burst, which only used just about 200 rounds. That extrapolates to 1,200 rounds per minute.... BUT you're firing two miniguns, so it's really only 600 RPM each. That's a far cry from the 2,000/4,000 that they should be. If the ROF was as high as it should be, the accuracy spread would be less of an issue. More bullets in the cone means more hits.

[gossamersolid 155]

The rate of fire on the miniguns are way off as well. I did a simple test last night. I took off in the AH-9 with the standard 5000 round load. I fired a 10 second burst, which only used just about 200 rounds. That extrapolates to 1,200 rounds per minute.... BUT you're firing two miniguns, so it's really only 600 RPM each. That's a far cry from the 2,000/4,000 that they should be. If the ROF was as high as it should be, the accuracy spread would be less of an issue. More bullets in the cone means more hits.

Rate of fire is affected by frame rate as well (not sure if this will ever get fixed, or if it even can).

[-=seany=- 5]

DCS Warthog is pretty good when it comes to FFAR accuracy, although it's lacking in representation of their lethality, or even actual warhead effect. Plus bare in mind, that FFARs launched from planes are more accurate, because of the relative wind being always close to being parallel to boresight. Launching FFARs from helicopters is problematic, the rocket have to accelerate from none, or low initial speed - therefore the velocity at the end of 1.07 second motor burn is lower - therefore any side wind have more impact on the flight path. Firing from hover, results in rocked going initially through area of downwash, resulting in pitch-up, making the rounds go on different trajectory, than in translational lift speed, or above. Any side-slip movement is also exaggerated by the rocket aerodynamic design.

It's not easy to compute impact point from this type of unguided weaponry - the most accurate, being the Apache gunship, utilizing, laser range finder, ballistic computer, and (something that is unique for its design) launcher elevation servos inside pylons - even with all of this, it's still very far from pinpoint accuracy. Even with all those advanced systems, Apache will get you accuracy resulting in 50% of fired rockets, landing in 26m circle, at 1000m. If you're engaging a target, you need a pinpoint accuracy - like a tank - the chances of hitting it are actually very slim. That's why the HYDRA 70 came with not only new engine, but a line of cluster warheads, like the M261, that have 9 grenades, that are released after a time delay.

So, a CCIP option on a small, "bare bone" helicopter like the AH-9? Yes, you could put ballistic computer, and turret with rangefinder plus Helmet Mounted Sight, but you won't get much out of it, you will still shoot roughly into an area. If I would be managing such Arma 3 project, I would rather concentrate on different warhead options for the rockets, than the aiming system. For example 160th SOAR Littlebirds, have no aids for aiming the miniguns and rockets - although the OH-6A had a sight for the minigun - you use those weapons "by feel".

ahhh, nice info thanks.

[Sundowner 11]

You may like this too:

That's how those Hydra 70 fly when you fire them in sideways flight at 45 kts.

[Maxzy 12]

So, we need more dispersed rockets and less dispersed miniguns. Is there a ticket yet :)?

[Tonci87 163]

The current miniguns are a great supression tool. You can supress a whole building, or a whole village center......

They need some tweaking.

And as JestersDead pointed out the ROF is waaay off

[Sundowner 11]

I tested the miniguns, and firing them with 33-35 fps, resulted in average of 1040rpm - half of what the lowest setting should be. Definitely some work will have to be done here. Although, that's resulting in one bullet trajectory being calculated per frame... can others test if there is such exact correlation between minigun fire rate and rendering speed ?

[max power 21]

Yes, weapons can only fire once per frame. To compensate in the past, the devs had a config token called multiplier, I think, to simulate multiple impacts in the same frame.

---------- Post added at 02:40 ---------- Previous post was at 02:33 ----------

Umm... the Hydra 70 with mk.66 motor in reality have 29mrads of dispersion, and that's 50% of rounds (for some reason DARPA is measuring differently for guns, rockets and bombs).

My data is still saying 12 mils. I couldn't find the study paper I used for our mod, but here are a couple of other sources:

http://www17.us.archive.org/stream/modelingindesign00wonn/modelingindesign00wonn_djvu.txt

The baseline rocket configuration chosen for the kit (HE warhead and super-quick

contact fuze) is an area suppression weapon. The unguided rocket has a total 12

milliradians (mill), one-dimensional dispersion, meaning that for every thousand meters of

down range fly out a 12 m error results (1 a or 68%).

http://www.globalsecurity.org/military/library/policy/army/fm/1-140/CH7.HTM

b. Crews can expect 7 to 12 mils of dispersion from rockets fired from helicopters.

If you have better information, please share it :)

Edited March 16, 2013 by Max Power

[Sundowner 11]

If you have better information, please share it :)

Check your PM.

[JestersDead 2]

I tested the miniguns, and firing them with 33-35 fps, resulted in average of 1040rpm - half of what the lowest setting should be. Definitely some work will have to be done here. Although, that's resulting in one bullet trajectory being calculated per frame... can others test if there is such exact correlation between minigun fire rate and rendering speed ?

Was this 1040 rpm total, or per gun? With 2 miniguns we should be seeing a combined ROF of 4000/8000 rpm unless they are slowing it down so that we have the same ROF as one gun would normally have. I'd be OK with the miniguns having a combined 2000/4000 rpm ROF selectable, but as they are now they barely fire faster than a LMG. Which makes them very difficult to use effectively. I'm sure it's something they're aware of though. It's a pretty glaring shortcoming if you've spent any time in the littlebird.

[Sundowner 11]

Per gun. The sample was the total ammo capacity, which took a bit of time.

BTW I tried to test the guns dispersion, but I run into some problems regarding the bullet holes effect. They're showing only on some objects - most of them to small for a 100m+ distance test. And there appears to be a very low amount of bullet impact stencils that can be displayed at a time, resulting in very small samples sizes.

[marcai 1]

Is there any update on this feature? Maybe it's just a trick of the eye, but the miniguns on the Ghosthawk appear to be firing at a far greater rate than those of the AH-9, which are still abysmally slow-firing beasts. I love flying around in the Littlebird, but its primary armament currently sits uselessly on its wings, as the rate of fire is so poor that it makes it near-useless against the majority of foes/ extremely lucky shots. I understand that it's not a primary attack helo, but its weapons should at least feel useful.