A-10A CBU-87 bug report

[Winston60]

Here's a longtime bug that's a holdover from the old DCS ver 1.2.

 

In the release version of DCS 1.5.2, the CBU-87's still fall short of the pipper when using CCIP bombing mode. Thank God the old Mk-20's can still be used, they hit spot on!

[BinaryMan]

I would love cbu-87s that actually release to their impact point.

[Winston60]

There's hope yet that this will be fixed. Ed has fixed all the other known bugs with the "A" model, just this one remains AFAIK.

 

Previous bugs were:

1. Pulling "G" sound bug - FIXED

2. CBU-87's fall short of the aim point.

3. Autopilot modes stay on HUD even with EAC off. - FIXED

4. Simplified PAC doesn't work in multiplayer - FIXED

 

Still, it would be nice if they would add some new features to the "A", like:

1. A key to toggle the PAC on and off instead of just having it go on with ground mode and cannon selected.

2. Make the altimeter adjustable.

[BinaryMan]

I believe you achieve the same effect of turning pac off by switching off EAC. However a proper method would be preferable.

 

I also believe both cbus fall short of their target. Additionally there might be a problem with the 97s dispensing to early in ccrp while in step dives (30). could you confirm?

 

Maybe ED are developing a fully modeled a10a :pilotfly:

(we can only hope)

[BinaryMan]

Additionally there might be a problem with the 97s dispensing to early in ccrp while in step dives (30). could you confirm?

jk, I was wrong.

[Winston60]

No, the PAC on the DCS "A" is not dependent on EAC on/off. The only thing EAC does in the simple "A" flight model is activate the various autopilot modes. The PAC in the "A" is simplifed. As soon as you select ground mode, then select the gun(get gunsight), the PAC is engaged and the nose comes down as long as the gun stays selected. Kind of a hokey way to do it but the effect can be minimized with a two stage trigger: 1st stage=select cannon(get gunsight), 2nd stage=fire gun, release trigger completely= deselects cannon(no gunsight), and disengages PAC.

 

Never dropped a '97 using CCRP from a steep dive. I prefer a level approach or a very shallow dive at the most with CCRP. I believe they fixed the CBU-97's falling short sometime back in ver 1.2. when they fixed the horrible slowdown when they exploded.

 

I don't think ED will fully model the "A". That's why we have the "C"!

 

Oh, and I forgot one more existing bug, but it's so minor: The canopy opening and closing sound continues long after the canopy has fully closed or opened.

[BinaryMan]

I believe you are wrong and I'm also guessing you don't fly with a Force Feedback joystick (which I will abbreviate to FF joystick).

The PAC system causes the aiming reticle to attempt stay on target only for the duration of the trigger's depression. This only happens when EAC is on and when the cannon mode is selected. This is because PAC depends on EAC to function, if EAC is off then PAC is non-functional.

 

I know what I am about to say will sound wrong but bear with me; I have full confidence that I am right.

 

I think what happens when you cannon select in the a10a is the "EAC/PAC Arms" causing a 2 degree elevator down change. For those who don't fly with a force feedback joystick this necessitates physically moving your joystick aft in order to maintain a level attitude. This is due to how trim works with non-FF joysticks. This trim behavior is consistent across both the A10A and A10C.

 

So I have a microsoft force feedback joystick 2 and it has this lovely feature where the motors on it do not engage if you don't have your hand on the stick. With out touching my FF joystick

Compare these behavior to how the aircraft functions without a FF joystick

[Winston60]

Yes, I see it seems to be completely different when using a FFB 'stick and your "hands off style". I don't use FFB anymore so I'll modify my findings on the PAC and nose down attitude to "when using a non FFB 'stick".

 

The closest thing for non FFB users to get what you are getting with FFB would be to have the PAC come on only when the gun was actually firing. This doesn't happen now as the nose comes down immediately when the cannon is selected in ground mode. I'm guessing you can't see this with your FFB 'stick installed.

 

We'll see how ED may or may not modify this in the future. They have broken then fixed then changed the operation of the A's PAC before, so who knows what they may do in the future. Thanks for letting us know what you're getting with FFB.

[BinaryMan]

I think you misunderstand. Currently, PAC does not come on when you switch to cannon. Currently what happens when you switch to cannon is the trim position of the aircraft changes. Because a normal joystick's input is always mapped around where the craft is trimmed to, the craft pitches down when the trim is set forward. The pitching down behavior is an effect of how joystick input is mapped. It is an inherent problem with control mapping that cannot be over come.

 

Furthermore, PAC for the A10A does work. And PAC is not the nose down behavior you get when you switch to the cannon. Currently, PAC is engaged only when the trigger is depressed, in cannon mode, with EAC on.

 

The closest thing for non FFB users to get what you are getting with FFB would be to have the PAC come on only when the gun was actually firing. This doesn't happen now as the nose comes down immediately when the cannon is selected in ground mode. I'm guessing you can't see this with your FFB 'stick installed.

I should also touch on this too. I can feel the aircraft's trim position change when I switch cannon. I would also like to reiterate that for you and me both PAC is only active when the conditions I mentioned above are met.

Edited February 26, 2016 by BinaryMan

[Windsortheater]

Why does the trim change when cannon is selected?

 

I find PAC function in the a-10a inconsistent. Sometimes the reticle walks up when firing like no PAC is engaged. Sometimes I stays on target. no Idea why.

[Winston60]

BinaryMan,

 

Thanks for that last paragraph in your last post. I was mistaking the manifestation of PAC with the nose down trim change you get when selecting the cannon. Now it all makes a bit more sense although when I fly the "C" model the nose down trim effect is so very much less than in the "A". Maybe it's because I have to trim the "A's" nose down so much more than the "C".

 

Thanks for the clarity. It makes sense to me now.

[Winston60]

Why does the trim change when cannon is selected?

 

I find PAC function in the a-10a inconsistent. Sometimes the reticle walks up when firing like no PAC is engaged. Sometimes I stays on target. no Idea why.

 

Don't know why, maybe BinaryMan has an answer to that.

 

Don't forget to switch on EAC or the gun reticle will rise when firing.

[Windsortheater]

Can someone post a trk or video of cbu87 deployment in an a-10a? Man I am having a hard time.

 

I'm using CCRP on the moving groups in the a-10a CAS instant action missions. I drop from >6K ft. I've tried dropping ahead of the moving group, way ahead of the moving group, right on the moving group, lagging the moving group. Nothing ever happens.

 

Thanks!

 

P.S. thanks for the EAC tip. Is there an indicator any where to confirm it's actually on? I know the switch doesn't move.. but is there a light?

[BinaryMan]

Why does the trim change when cannon is selected?

So in the A10C PAC relies on EAC to be on. A10A is the same way also. In the A10C when EAC is turned on in flight it causes a 2 degree elevator down change. Inversely turning it off causes a 2 degree elevator up change. Also, EAC relies on other things to be on aswell but that's besides the point.

So as I said earlier:

I think what happens when you cannon select in the a10a is the "EAC/PAC Arms" causing a 2 degree elevator down change.

Basically for the A10A, despite EAC being on and all of the autopilot functions working; before you switch to cannon mode it has yet to actually turn on. I think this is most likely an ED programming thing to get basic PAC functionality working. (I don't think the A10A always had PAC) (I'm guessing they stole code from the A10C) (don't quote me on this, its a lot of presumptions)

More info on how the gun system works irl here: http://forums.eagle.ru/showpost.php?p=1256979&postcount=1

I find PAC function in the a-10a inconsistent. Sometimes the reticle walks up when firing like no PAC is engaged. Sometimes I stays on target. no Idea why.

I did forget one important thing, PAC won't work if you have air brakes on. Another problem might be low airspeed. As I understand PAC has a limited range of motion and rate of change. This allows PAC to be overridden by the pilot and prevents it from issuing crazy control inputs. Because of this if your airspeed is to low, below 200 ish, you might find PAC is unable to keep the reticle on target.

 

There is no indicator for EAC currently. Also I think you will find the best success for gun runs with dive angles 30 to 40 degrees. Against tanks ranges from .5 to 1 NM, Against all other targets .5 to 2 NM. And airspeed excess of 220 knots. Hope this helps Windsortheater.

[Winston60]

Can someone post a trk or video of cbu87 deployment in an a-10a? Man I am having a hard time.

 

I'm using CCRP on the moving groups in the a-10a CAS instant action missions. I drop from >6K ft. I've tried dropping ahead of the moving group, way ahead of the moving group, right on the moving group, lagging the moving group. Nothing ever happens.

 

Thanks!

 

P.S. thanks for the EAC tip. Is there an indicator any where to confirm it's actually on? I know the switch doesn't move.. but is there a light?

 

Well.... there's the problem with the CBU 87's falling short in CCIP mode (read first post) so I'm not surprised there's a problem with CCRP mode as well. I just don't use CCRP mode for the 87's so I never noticed. I usually attack moving ground vehicles with the CBU 87's in CCIP mode starting from about 4,000 to 5,000 ft altitude. That's how I noticed the "falling short" problem about a year ago. If there's a problem with the bomb itself the error would be noticed in CCRP mode as well as you have discovered. This has been a bug for quite some time from back in ver 1.2. Maybe they'll get around to fixing it someday. The CBU 97's work nicely in CCRP mode, and you can still load on the Mk-20 Rockeye if you load the mission into the mission editor and change the loadout. Rockeyes hit spot on in CCIP.

 

The toggle switch for the EAC is not animated and there's no light. I switch on my EAC right after takeoff and verify that it's on by briefly turning on the LAAP in Altitude/Bank mode. If it comes on (as shown in the bottom left of the HUD) then the EAC is on because the autopilot won't work with EAC off.

[Windsortheater]

PAC won't work if you have air brakes on.

There is no indicator for EAC currently.

 

This!!! I had been using air brakes to manage time on target. This was my problem. Thanks!!!

 

If I manually trim out the automatic downward trim that occurs when cannons are selected, will that mess with PAC effectiveness?

Edited February 28, 2016 by Windsortheater

[Windsortheater]

I usually attack moving ground vehicles with the CBU 87's in CCIP mode starting from about 4,000 to 5,000 ft altitude. That's how I noticed the "falling short" problem about a year ago. If there's a problem with the bomb itself the error would be noticed in CCRP mode as well as you have discovered. This has been a bug for quite some time from back in ver 1.2. Maybe they'll get around to fixing it someday. ..

 

Given the 87's follow a ballistic path and have a non adjustable dispense height (what is it in the a-10a??), how far ahead of desired impact point do you set your reticle during a CCIP run?

 

For 97's given they haVe chutes and do not follow a ballistic path from dispense height (1800ft??) where do you generally set your reticle aim point?

 

 

The CBU 97's work nicely in CCRP mode, and you can still load on the Mk-20 Rockeye if you load the mission into the mission editor and change the loadout. Rockeyes hit spot on in CCIP..

 

I will try the rockeyes. Thanks.

[Winston60]

I always try to engage a moving column lengthwise from directly in front or from the rear. This maximizes the hits when dropping multiple pairs of cluster munitions right along their route. CCIP is my preferred mode for moving vehicles.

 

For both CCIP and CCRP if attacking from the front, aim just in front of the lead vehicle. If attacking from the rear, aim just in front of the vehicle you want to hit. In CCIP if you think your aim was good, release a second or third pair of bombs.

 

Always drop in pairs to keep the aircraft balanced.

Edited February 29, 2016 by Winston60

[BinaryMan]

Windsortheater of course it depends on how high you are above your target's elevation when you release as well as air speed but generally you'll find that for a stationary target you have to aim bottom of the dashed circle if not further.

[Windsortheater]

Windsortheater of course it depends on how high you are above your target's elevation when you release as well as air speed but generally you'll find that for a stationary target you have to aim bottom of the dashed circle if not further.

 

Thanks for posting that. Showed me exactly what I was asking. Seems the key with the 97's is to use a strong amount of lead to time the dispense (1800ft) pretty much directly above the target.

 

With 87's do you aim in a similar way?

 

That was a CCRP release right? (noticed CCRP switch did not set).

 

Thanks again.

[BinaryMan]

Thanks for posting that. Showed me exactly what I was asking. Seems the key with the 97's is to use a strong amount of lead to time the dispense (1800ft) pretty much directly above the target.

 

With 87's do you aim in a similar way?

 

That was a CCRP release right? (noticed CCRP switch did not set).

 

Thanks again.

Yeah you have to drop pretty far behind your targets with the 97s. however be aware that as altitude increases and speed decreases you should have to aim as far back. This might be mostly negligible.

 

You don't have to aim as far back with the cbu87s as the bomblets maintain their inertia.

 

It was CCRP.