[FIXED] Low Drag bombs always fall short, DYK and PLAN

Two tracks attached of PLAN bombing. Centerpoint is way short. Radar ranging used both times, correct QFE entered.

bombs_short1.trk

bombs_short2.trk

And here's a DYK run.

bombs_short3.trk

Is no one else having this issue? It's actually impacting my mission effectiveness. At the low altitude and with shorter strings I'm forced to guess an overshoot point to get the bombs to land

Ill run a few tests to see for myself.

 

I have not delved too much into the bombing with viggen yet.

Seems fine to me, I've hit two targets without problem just now. Same goes for my wingman.

Seems fine to me, I've hit two targets without problem just now. Same goes for my wingman.

 

How were the centers of your strings? I can hit too, but usually it is the last few bombs

Are you setting the local air pressure of the target site on your altimeter before initiating your weapons setup? I ignored it before but have found that this contributes to causing short drops for level flight delivery of retarded bombs. Airspeed and exact altitude also affect level drops of retarded bombs, especially when the target is in rolling or hilly countryside.

 

I have found that CCIP pop-up attacks with slicks is very accurate (when I preset the local pressure).

All of the following is based only on your first track:

 

 

The first problem I had was my pipper jumped, even at what I thought was the "correct" safety height. The kneeboard says "Medium" but CK37 directs to 600M. You tried at 400M (as did I at first).

 

Next, it's hard to accurately place the pipper when the target ring blocks it visually. After 2-3 "short" passes I zoomed in to accurately sight the target, then achieved a direct hit (center of the salvo). This occurred after I landed and rearmed, which allowed me to calibrate both altimeters to my liking, and set QFE using my personal technique.

 

So now that I knew Heatblur's work was properly functioning.. I set about the answer the question: Why can't LastRifleRound figure this out yet?!?!?

 

Here you go!

Edited February 2, 2020 by randomTOTEN

Are you saying his aim point is wrong? I don't follow

Are you saying his aim point is wrong?

It's probably more accurate to call it a 'designate point'.. but yes.

 

 

Also his attack height was incorrect. And he didn't maneuver as directed by the sight symbology. But the computer can compensate for those errors. It can't compensate for giving it the wrong desired impact location. It put the bombs exactly where he told it to put them, even with less than ideal launch conditions.

Edited February 2, 2020 by randomTOTEN

So,

I apologize to LastRifleRound here.

 

 

On my assertion that he performed a bad designation, I replayed the track with the intention of uploading a screenshot of this event. I took control of only the views, and attempted to use time deceleration to pause the sim immediately before designation. What I found is the following image, that you IN FACT made a designation CORRECTLY on the visible target. So my apologies.. I seem to be jumping the gun here.

 

 

This leaves the question, if you designated the impact point properly.. why did CK37 miss? Why was I able to make at least 1 successful pass on the target (and have had major difficulty repeating)??

 

 

Investigation continues....

From "bombs_short1.trk." Some of my passes are falling short, some of them are very much right on the money. I'm not sure what the correct formula is, but it is possible. At 400M the pipper drops at the moment of designation, indicating a climb... that means I'm below safety altitude.

 

 

 

From "bombs_short2.trk."

 

 

I think I see the pattern, and have re-learned how to bomb in the Viggen.

Your pass in this track is at M0.66. I let you set up the jet, then took control for the run-in. I achieved the following results at an attack speed of M0.80. I seem to remember being faster worked better.

 

 

That's the only factor I changed, and it had this result (on the first try).

YUP

VIGGEN LIKES GOING FAST. It's just like the MiG-21 in that respect. You can solve problems by just going faster LOL!

 

 

I let you set up the jet for "bombs_short3.trk." When you finished, I took control and hit the deck. I pulled up, nosed it onto the target, and hit AB3.

 

 

This was my first (and only pass) on this track. Also I forgot the pull up during the release.. that might have been why the interval was so tight (I didn't observe what interval you had set)?

Edited February 3, 2020 by randomTOTEN

Did you make sure your speed and altitude was adequate?

Edited February 3, 2020 by =JUICE=

Okay,

 

 

something screwy is going on with "bombs_short1.trk." The only way I can regularly get a direct hit is by following this steering order. But this is a Level Release (M/71 - PLAN/ANF).

Why am I being ordered to climb for the release? That's not what's depicted in the manual. If it's not clear from this picture, the steering order starts the horizon at trigger pull, then quickly deflects to full up... not a slight "climb a little" but an order to put G's on the airplane. Once it reaches full up, it starts from full down and returns to the horizon. At that point, pretty much the attack is already complete.

Edited February 3, 2020 by randomTOTEN

You are seeing the confluence of two screwy things. This location is like the DCS bermuda triangle.

 

If you designate directly on the target without radar ranging, what you have actually designated is a point behind the ammunition depot. Therefore, the bombs will land on target (because they typically fall short).

 

As for track 1, you'll notice another odd behavior. The ground altitude at that location is higher than what the ME thinks it is. This is why designation without radar is too far away, and why when you designate with radar, if you've been maintaining 400m LD, you'll be asked to climb

 

I don't believe it's accurate that PLAN mode should enforce a certain speed or minimum speed, so I believe this is not intended behavior. Also, we know they've been messing with the algorithm because the last patch notes indicated "improvements to LD bombing" but did not specify what that means. If it were a new methodology or restriction, I'm sure they would have listed it in the patch notes.

 

Edit: my interval was the default (15 I think). Looks like that tight string was dropped in a dive

Edited February 3, 2020 by LastRifleRound

Why are you calling this a problem with the Viggen, when you specifically chose a location on the map with a possible elevation bug?

 

 

Don't you think this confounds the bug report? Especially when you made no mention of this fact.

 

 

Your OP title is "always fall short" not, "fall short with map elevation error"

Guys, I really appreciate your inputs on this "issue" here. Nice story all this.

 

One question comes up in my head:

Does - in your opinions - the bombing in PLAN mode work, or not?

What I understand (after reading all this) is that it works everywhere except for the magic area in Caucasus.

 

Can I / can we - at this certain point - summarize this for people not having much time to read but spending some little time for some bombing runs after work ... :smartass:

 

Thanks guys!

My opinion is that it works just fine. It just requires practice.

Why are you calling this a problem with the Viggen, when you specifically chose a location on the map with a possible elevation bug?

 

 

Don't you think this confounds the bug report? Especially when you made no mention of this fact.

 

 

Your OP title is "always fall short" not, "fall short with map elevation error"

 

You specifically asked in one of your posts why sometimes the bombs hit and other times they didn't. I was simply explaining this could be why. If you weren't careful of having AGR active at the time of designation, you may be designating long, thus your bombs hit the target as normal, masking the bug. No need to get upset at me, I assumed most people waited for AGR. This is not the only spot in DCS where this is an issue. It might not even be a "bug" per se. I think right behind that ammo depot the terrain might dip a bit. If you designate before radar you are really looking "through" the ammo depot, as, without radar the jet doesn't know it's there and therefore thinks your designating some spot behind it (kind of like in the A10, if you designate with the TPOD but don't lase, your bombs will always fall long of a structure or vehicle for this very same reason). The dip can exacerbate this effect and even more so the low angle of observation the Viggen has because of the low altitude methods you are likely to be using. So no, if you use AGR like I did it is not a confounding factor. It is also accounted for in the fact that I've flown this test mission many times before without this specific issue.

 

 

Why not provide a track of one of your runs that hits the target so I can examine what you are doing? And also one of your misses? It would be better if worked together on this.

 

I want to stress that before the update I ran this same mission and had no issues hitting that target hundreds of times. The "elevation error", if it exists, only affects DESIGNATION, not the actual bombing algorithm, which before now was working fine.

 

My opinion is that it works just fine. It just requires practice.

 

You can't hit the target consistently and have no idea why. This isn't a valid conclusion in the face of the observable data.

 

Further, which specific procedure do you believe I failed to follow in the track? If it is practice, that implies I did something wrong. Where EXACTLY did I go wrong? Correct QFE, non-loaded aircraft, correct designation, correct altitude, correct dial set up, bombs land short. You mention speed, but there is no minimum speed for any of these bomb modes. Mach .8 is the generic recommended run-in speed for any target point in the Viggen, but it's not the only one and it certainly hasn't been a requirement for the past 3 years of the module existing. If it is now then I'm right that something did indeed change and it would be valuable for people to know that. The only opinion there should be is whether we believe it is intentional. Also, I would like an explanation for why such a restriction does not affect NAV or RR modes (also further proof the elevation issue is really only on designation without AGR)

 

It worked before the update in that same exact spot. It works AT LEAST inconsistently now.

 

I've flown this practice mission 100's of times to keep my skills sharp. I know EXACTLY how to drop those bombs and nail those targets. I use the same one all the time. It's why I'm able to spot subtle changes right away. I've been using that mission for over a year. The reason the vehicle is on top of the bunker is so I can even practice the RR mode in ANF, which, by the way, works perfectly. Every weekend, I make sure I can hit that target in my sleep in PLAN, CCIP, DYK, RR and do a passable job with NAVTOSS (which works after the update, before it would always land long. Related? Maybe.). I land after each time (except this one, as I generated it specifically for this) using breaks, straight ins, sometimes I'll throw fog in, hit in RR, and land IFR. I have a youtube video demonstrating PLAN where I shack THAT EXACT TARGET in THAT EXACT MISSION that you yourself watched and commented on. I know what I'm doing in the Viggen and I can hit that target in every other bomb mode center-string. I would not waste anyone's time producing a map location or method that I wasn't sure was hitting the target previously, and there's plenty of evidence that I was hitting targets just fine.

 

Until someone gives me an actual explanation that I did something actually wrong, I'm going to go ahead and say something is up because that is what the observable evidence tells me.

Edited February 4, 2020 by LastRifleRound

At best I can only determine 2 deficiencies on your part.

 

1. You don't have enough speed for the attack.

 

Whether this is accurate or not, whether this is documented or not, despite any lack of warning from the aircraft of being outside of launch parameters, through my testing this is the single most important deciding factor in your failure IMO

 

2. You don't follow the guidance.

 

This is the very same guidance you championed they change, in the hopes it would be easier to interpret. (I still assert that this is not true.. it's harder to interpret now than before, but I can still work with it) You correctly designated the target via UNSAFE, the pipper moved to command a correction. Instead of adjusting the aircraft to comply with this indication, you reset the system with SAFE, found the pipper again in the correct location, and again correctly designated with UNSAFE. The pipper dropped, CK37 was commanding a pitch up. You only did so very slightly and with some delay.. it was barely perceptible (I even doubt it was intentional). CK37 ordered trigger press. It then ordered a drastic climb, you did not follow this steering order either.

 

I have only been able to pretty much guarantee correct salvo placement when I follow this steering order.

 

There are questions if this steering order is correct for the RL aircraft, but in DCS following it works, even for just the seconds of the release, as my track shows.

 

So you can't hit the target consistently and have no idea why and your conclusion is that it works perfectly.

I told you why. I was rusty. That (apparently) resulted in my flying too slow, and not following the guidance.

 

bombs_short1.trk is the only track in which I had a problem. In your 2 other tracks my success rate was 100%. Even when I miss in your track, my first assumption is that I have made an error, and seek to discover it.

 

At the very minimum, the release calculation is working just fine.

 

 

The posted track is the same as "bombs_short1.trk." If you can't tell, I take control of your track just as you look over your right shoulder. Also it's obvious you're using a better joystick than I am:joystick:

And that target ring is annoying, so I get rid of it.

pilot skills not heatblur code.trk

Edited February 4, 2020 by randomTOTEN

At best I can only determine 2 deficiencies on your part.

 

1. You don't have enough speed for the attack.

 

Whether this is accurate or not, whether this is documented or not, despite any lack of warning from the aircraft of being outside of launch parameters, through my testing this is the single most important deciding factor in your failure IMO

 

2. You don't follow the guidance.

 

This is the very same guidance you championed they change, in the hopes it would be easier to interpret. (I still assert that this is not true.. it's harder to interpret now than before, but I can still work with it) You correctly designated the target via UNSAFE, the pipper moved to command a correction. Instead of adjusting the aircraft to comply with this indication, you reset the system with SAFE, found the pipper again in the correct location, and again correctly designated with UNSAFE. The pipper dropped, CK37 was commanding a pitch up. You only did so very slightly and with some delay.. it was barely perceptible (I even doubt it was intentional). CK37 ordered trigger press. It then ordered a drastic climb, you did not follow this steering order either.

 

I have only been able to pretty much guarantee correct salvo placement when I follow this steering order.

 

There are questions if this steering order is correct for the RL aircraft, but in DCS following it works, even for just the seconds of the release, as my track shows.

 

I told you why. I was rusty. That (apparently) resulted in my flying too slow, and not following the guidance.

 

bombs_short1.trk is the only track in which I had a problem. In your 2 other tracks my success rate was 100%. Even when I miss in your track, my first assumption is that I have made an error, and seek to discover it.

 

At the very minimum, the release calculation is working just fine.

 

 

The posted track is the same as "bombs_short1.trk." If you can't tell, I take control of your track just as you look over your right shoulder. Also it's obvious you're using a better joystick than I am:joystick:

And that target ring is annoying, so I get rid of it.

 

Sorry but your assessment on speed is wrong. Same result regardless of speed. Here are three additional tracks, this time, target is only 16ft ASL on very flat terrain. One track shows center hit, the other two show center short (in fact, whole string is short). Both times I followed the steering order. Steering order has nothing to do with this. It's bugged and the times you hit are probably due to missed designations.

 

Notice on the center hit, I accidentally designate long. Notice on both runs my airspeed is above the level you suggest, and also notice I follow the steering order on all.

 

Also, I use a Saitek X52, not exactly top of the line. It's almost 10 years old. I love it, but it's hardly precise.

 

PS Target ring drives me nuts, too. Rarely placed right and it gets in the way of getting eyes on. I feel your pain.

bomb_ok.trk

bomb_short5.trk

bomb_short6.trk

Also you don't need to create a target point to get the ring visible, it will show up even when the current fix is B1 and ANF

 

 

 

bomb_ok.trk: you designate a little long. Not that bad, good enough. Obviously now the pipper should be just above the bunker, but you maneuver to place the pipper at the bottom of it. This is fact a command to climb. At the last moment you begin to follow the steering order, and even at M0.6 your salvo is pretty much right where you tell it.

 

 

bomb_short5.trk: you didn't follow the steering order

 

 

bomb_short6.trk: you got a "inside fragmentation zone" warning at weapon release. Seems the problem might be the steering order, but you pulled the trigger before the "wings" and so had to rely on it. I also noticed on both short salvos the aircraft was in a slight descent..perhaps this is a factor? Any descent results in an invalid calculation during "level release?"

 

 

Yeah, my designation was long too.. whatever, I went with it. The Salvo landed EXACTLY where I commanded it to.

 

 

Heatblur's Viggen code (at least in terms of release calculation) is just fine.

 

 

"Low Drag bombs always fall short, DYK and PLAN" is a false statement.

 

 

EDIT: Here are the altitude records for each of your passes. From UNSAFE to FALLD LAST

ok: approximately level @ 400M (+/- 20M)

short5: 430-390M continuous descent through the attack

short6: 440-390M continuous descent through the attack

my very first try at bomb_short6.trk

Edited February 4, 2020 by randomTOTEN

Also you don't need to create a target point to get the ring visible, it will show up even when the current fix is B1 and ANF

 

 

 

bomb_ok.trk: you designate a little long. Not that bad, good enough. Obviously now the pipper should be just above the bunker, but you maneuver to place the pipper at the bottom of it. This is fact a command to climb. At the last moment you begin to follow the steering order, and even at M0.6 your salvo is pretty much right where you tell it.

 

 

bomb_short5.trk: you didn't follow the steering order

 

 

bomb_short6.trk: you got a "inside fragmentation zone" warning at weapon release. Seems the problem might be the steering order, but you pulled the trigger before the "wings" and so had to rely on it. I also noticed on both short salvos the aircraft was in a slight descent..perhaps this is a factor? Any descent results in an invalid calculation during "level release?"

 

 

Yeah, my designation was long too.. whatever, I went with it. The Salvo landed EXACTLY where I commanded it to.

 

 

Heatblur's Viggen code (at least in terms of release calculation) is just fine.

 

 

"Low Drag bombs always fall short, DYK and PLAN" is a false statement.

 

 

EDIT: Here are the altitude records for each of your passes. From UNSAFE to FALLD LAST

ok: approximately level @ 400M (+/- 20M)

short5: 430-390M continuous descent through the attack

short6: 440-390M continuous descent through the attack

 

 

 

Look, you and I are never going to agree on anything it seems, and that's ok.

 

I just viewed your track, and honestly, I'm shocked at your conclusion.

 

I am saying that in PLAN bombs always fall short of the designation point. To counter this, you post a track where you designate a point that your bombs fall short of. Here is a picture of pre-designation. Your actual designation was a few ms after this, and was actually FURTHER OFF than this. Your initial string was going to hit dead center of the target. It should not have. The latter half of the string went way long because you chased the steering order (you shouldn't when you're that close, the error is magnified since it's an actual point in the sky. The steering order is a guide) and yanked all the bombs forward at that point.

 

Re. my altitudes, again, supports my claim. In the ok track I SHOULD HAVE MISSED or at the very least the center of the string should have been forward of the target. In your posts above, you admit my designation is too far, and you admit I'm flying the altitude perfectly with the correct speed in this latest post. If this is true, then why didn't the bombs land where they are supposed to, which is the point I designated? The goal of this test isn't to merely hit the target, but to test if the bomb center point is at the pipper designation. The target is just a measurement tool. Just because I hit the target in that track doesn't make it a "good" run, because the goal of the track is to test the Viggen.

 

Your track proves my case. You keep adding argumentation that supports my claim, then conclude my claim is wrong. I don't know what to say other than for Ragnar et al, there's plenty of observable evidence if you want to look at this and draw your own conclusion.

 

For now, if you want to hit a target, you will need to designate long like Random did in his track, and I did before. You may conclude that the code is "fine" as a result, but scientifically, that aim point is not the center point where the bombs will land, and the difference is not random, but consistent.

 

Again, until someone provides evidence to the contrary, I'm sticking with this is an unintentional bug introduced in the latest update.

 

Here's the picture of your designation point, way long, not "good enough". Most people will be putting the pipper on the target and will miss as a result. If you want to persuade me, post a track where you're level, designate the center of the target, and hit close to the center of the target with the center of your string, otherwise I'm unconvinced.

 

 

PS Re. designating the mission point, I merely do this for muscle memory. The step can be skipped if desired to run the experiment. I do this every time in case I designate a different point with radar for whatever reason as I don't want the nav polygon changing

Edited February 4, 2020 by LastRifleRound