Rockets too long

No matter how often I repeat, my rockets always fall too long. They impact some meters behind the target.

Referencing these two threads:

Viggen Rocket Employment in 2.5

Help with rockets.

where people claim rockets falling too short, I think the latest fixes to the sighting system may have overshoot the goal.

Here's a small showcase:

Please don't hesitate telling me if I've done a pilot error. But as far as I know I'm doing the procedure correct. Maybe I'm too low and thus my dive angle is too shallow, I don't know.

Motion is off, QFE is set correctly (spawned at same height), radar ranging is used and I have no NAV drift (spawned there and TERNAV updates too).

Also, I've noticed that the waypoint ring is not on the target. But this does not seem to be a bug according to this thread.

Version is Open Beta 2.5.0.14304.

+1 I can only agree. It's the same for me. Now they are hitting long (i.e. behind the target point).

+1 Just tested this on Coldwar, It's an issue

I've been having the same issue with bombs as well. Haven't ruled out myself being the culprit yet, though.

No matter how often I repeat, my rockets always fall too long. They impact some meters behind the target.

 

Referencing these two threads:

Viggen Rocket Employment in 2.5

Help with rockets.

where people claim rockets falling too short, I think the latest fixes to the sighting system may have overshoot the goal.

I don't think there have been any changes to rocket employment since the debate in the first thread you referenced and last time I tried it worked great in 2.5.

Motion is off, QFE is set correctly (spawned at same height), radar ranging is used and I have no NAV drift (spawned there and TERNAV updates too).

 

Also, I've noticed that the waypoint ring is not on the target. But this does not seem to be a bug according to this thread.

All NAV related things (drift, TERNAV and waypoint ring) are not a factor here as rocket employment does not make use of any of this. The only systems that matter for rocket employment are QFE and radar ranging.

I don't think that's a good example QuiGon. You didn't fly what is considered a normal attack pattern on the run. How the rockets hit in your example is not a good test of how they will hit when preceded by a high speed, low altitude approach, then a pop-up, roll, and dive onto the target. Also, make your starting spot near sea level, have a couple of waypoints to the target, and set a target point in the hills where the QFE value is 50 - 60 points different. For instance, start at a QFE of 940 or so and make an attack at 880.

The video is not mine. It's from the other thread that was linked by the OP. I posted it because it looks exactly like it does on my end. I'm very seldom using the rockets, but I did use them two weeks ago in the Viggen Red Flag campaign (on Nevada) and they hit on point, just as advertised. In that mission I did start on the ground and the target QFE was a different one than the one I started with. I conducted a high speed, low altitude approach, did a pop-up and dived on the target and fired when the wings showed up. The rockets hit exactly on point.

I'm having them fall long and short, never quite on. Long occurs when the pipper is right on the target, firing when the "wings" appear on the pipper. Short occurs when the pipper is right on the target, close range, no "wings."

Both of these were in ANF mode. Is radar ranging on by default or do we have to manually turn that on?

2 months ago, I had the rocket falls short. Maybe there's a bug somewhere.

They do fall long for me.

Set up a mission with spaced apart fuel-trucks. Set QFE & use ANF or NAV. Fire the rockets in ENEKL mode (4 rockets/trigger), with an pop-up attack.

Can't hit a single truck! :huh:

Last night I had the rockets hit dead-on. Not sure what I did. Used ANF, also set QFE just to make sure, and had the radar altimeter on. Pretty sure it's the same as I always do.....

I've tested a little bit more with rockets using ANF mode. The pitch angle when you're firing your rockets seems to have quite a big impact on how good you hit your aiming point. The sweet spot seems to be around 18-20 deg. If you fire with that pitch you will hit dead on. Shallower pitch angles generate hits beyond the aiming point. Steeper dive angles generate hits in front of the aim point.

Don't know if this is the expected behavior or if something is wrong the aim and range calculations.

Is it possible to use rockets in NAV mode, using only QFE?

Rockets are not lazer beams. I have noticed more ballistic changes on said ordinance in 2.5. Weather, wind and dive angle all seem to come in play now. Its not just the Viggen..

I don't know what you mean by "using only QFE" but yes, you can deploy rockets in NAV mode instead of ANF mode too (a quick mode).

Therefore, as usual, the weapon selector goes to ATTACK. And the release mode selector needs to be in SERIE (IMPULS, which engages long range ARAK mode, is only possible in ANF).

Then you go trigger unsafe (the HUD symbology changes) and fire.

QFE is used to compute range to target. Radar ranging and target motion measurement are not used in this quick mode.

See manual page 294 (last note for ARAK employment):

Rockets are not lazer beams. I have noticed more ballistic changes on said ordinance in 2.5. Weather, wind and dive angle all seem to come in play now. Its not just the Viggen..

Yeah. But on a 1km shot from a diving angle with fast rockets, stuff like wind or weather has little to no effect (and the Viggen has a wind measurement unit).

The only important thing for the impact point computation at this point is range, dive angle and speed. The computer should be able to compute the release point correctly.

I'm sure it's not only Viggen's fault, it worked before. It's always the same, DCS engine changes and all modules need to be adapted.

Yeah. But on a 1km shot from a diving angle with fast rockets, stuff like wind or weather has little to no effect (and the Viggen has a wind measurement unit).

The only important thing for the impact point computation at this point is range, dive angle and speed. The computer should be able to compute the release point correctly.

 

I'm sure it's not only Viggen's fault, it worked before. It's always the same, DCS engine changes and all modules need to be adapted.

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The rockets in the Mi8 and AV8B seem to work fairly well for me. If I have time, I will try the Su-25A and see if the rockets are misbehaving in it too.

I've tested a little bit more with rockets using ANF mode. The pitch angle when you're firing your rockets seems to have quite a big impact on how good you hit your aiming point. The sweet spot seems to be around 18-20 deg. If you fire with that pitch you will hit dead on. Shallower pitch angles generate hits beyond the aiming point. Steeper dive angles generate hits in front of the aim point.

Don't know if this is the expected behavior or if something is wrong the aim and range calculations.

You're absolutely right about the dive angle. I've run couple of tests myself and if I keep the dive angle at the white line on ADI (I think it's 15 degs dive) I'm able to hit the targets regardless of QFE settings. I've been hitting targets now with altimeter set at 1150 hPa while QFE was 976, no problem.

Yes, testing this right now. QFE setting doesn't seem to have any impact on how accurate you hit. Only dive angle has. And the sweet spot dive angle seems to be closer to 15-16 deg rather than 20 (which I stated before).

The same behavior can be noticed with AKAN.

You're absolutely right about the dive angle. I've run couple of tests myself and if I keep the dive angle at the white line on ADI (I think it's 15 degs dive) I'm able to hit the targets regardless of QFE settings. I've been hitting targets now with altimeter set at 1150 hPa while QFE was 976, no problem.

Yes, testing this right now. QFE setting doesn't seem to have any impact on how accurate you hit. Only dive angle has. And the sweet spot dive angle seems to be closer to 15-16 deg rather than 20 (which I stated before).

The same behavior can be noticed with AKAN.

ANF mode uses radar ranging to calculate balistics. QFE is only used in NAV mode.

So far I've tried rockets in four modules: Viggen, Harrier, Hip, and Grach-A. The Viggen appears to be the only one with fickle rockets. The Grach-A in particular shoots S-8s like a laser.

I don't tend to have a problem, qfe is a must, but sometimes they just plain miss, I can re start and they are spot on, I think/assume this is all down to pilot error/conditions at the time.

the most problem I ever have with the is in single mode, much better to just chuck the lot out and have a higher hit chance

Still falling long, firing signal too late ?

I also have this issue in 2.5, my rockets are consistently falling long when firing at the signal (wings).

It seems like the firing signal is given way too late, if I fire while the timeline is still outside the markers, I get much better results.

I hope that Heatblur can solve the issue because the Viggen is a pleasure to fly and fight with :thumbup:

I also have this issue in 2.5, my rockets are consistently falling long when firing at the signal (wings).

 

It seems like the firing signal is given way too late, if I fire while the timeline is still outside the markers, I get much better results.

 

I hope that Heatblur can solve the issue because the Viggen is a pleasure to fly and fight with :thumbup:

The devs are working on it:

Hey I write here but this relates to https://forums.eagle.ru/showthread.php?t=203864 and https://forums.eagle.ru/showthread.php?t=184496 as well as rocket-sight inaccuracies too.

 

I've spent the last 1-2 months trying to figure out how the sights are all inaccurate all of a sudden. Among things I've discovered is that the radar-measurement was calculated wrong and other smallish things, I've also found that ED changed their atmospheric model at one point (which I knew but choose to ignore in hopes the problem would go away). Anyway, the newest member of the dev-team Grover managed to make a new fit for the barometric altitude calculation so the calculations is again close enough. This effects pretty much all weapons in the Viggen. You can tell if the altitude calculation is off in the sight-modes that have the MålUtpekningsSymbol (MUS, I think its called Target Indication Ring in the english manual) if the ring appears either under ground or floating above the ground. The fixes is going through the hoops right now...

 

Btw, thanks for the video! They do illustrate it very nicely!