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

I posted 2 tracks, you've only looked at one apparently. What you're asking me to post

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

It's already been posted.

I guess I'm going to have to compare screenshots of designation and location of the salvo.. because apparently now the target is not longer a good enough reference. While we're at it, we might as well start measuring the actual impact interval.

The manual is clear here,

Pilot flies according to the steering order so that commanded altitude is maintained

I posted 2 tracks, you've only looked at one apparently. What you're asking me to post

It's already been posted.

 

 

I guess I'm going to have to compare screenshots of designation and location of the salvo.. because apparently now the target is not longer a good enough reference. While we're at it, we might as well start measuring the actual impact interval.

 

 

The manual is clear here,

It's not "a guide" you're told by the manual itself to follow it.

1. I just looked through your posts again. Still see one track

2. Of course you have to compare the designation point to the salvo center. That is the entire point of the thread. If I designated something 1km away and hit the target, would you say that's working properly?

3. Yes, to maintain altitude. It is like ILS. The closer you get to it the more the MOE shrinks until it is so small it is irrelevant and impossible to follow. Again, your track shows this. You chased the order and it screwed up the latter half of your interval.

Note the OP doesn't say "I can't hit targets in the viggen". It's that they fall short of where you point them. I'm good enough with the Viggen to be able to consistently overcome this (you saw the lovely string I put down on the ok track). That's not the point. The point is that it doesn't work right. I can post 12 tracks of me purposely aiming long and shacking all kinds of targets at various altitudes and speeds, but I think I've done enough for this bug report.

I say it's a bug and I'm walking away from it.

so...uhh... I'm going to change my mind on this.

I tried to eliminate as many variables as I could.

The target is the airfield I just took off from, at the threshold I was standing on when I calibrated my altimeter to 0M QFE.

I have my safety altitude set to LOW, which should coincide to 200M.

I run it at M0.7-M0.8, 200M, I engage altitude hold, and I designate the very beginning of the threshold (where the pavement ends). Pipper remains at the designation point = no correction required. Bombs landed before the threshold.

I repeated this again.

I tried again without altitude hold, and trying my best to follow the steering order. This introduced pilot error. Same result.

It seems if I keep 1G on the aircraft throughout the run this is my result.

And yet, if I put extra Gs on the airplane, I get this!

The salvo is centered on the threshold, but the distribution is weird. More bombs are towards before the threshold than after. Also some quick math here, this is 10M interval. 10M x 16 Bombs =160M.. or 524ft.

This is at least 3x that impact distance. Very likely as LRR said due to the Gs.

I wonder if the Loft release logic bled through to Level Release?

I too have noticed short drops from my designation.

I too have noticed short drops from my designation.

Your screen name is legendary :thumbup:

Thanks haha

Any word on this HB?

Just tried RR, NAV and PLAN modes again. ALL are falling short. This is a big problem. Viggen cannot accurately drop LD bombs in anything but DYK, probably because the pull-up cue is always too far up so it compensates for the issue (plus you're in a dive). HB you really need to look into this. I can attach more tracks if necessary, but the ones I've already posted should suffice.

Ran another try just to be sure. Here's a track of a run in NAV. Used to hit this all the time no problem. Now, bombs short.

bomb_short7.trk

Bump

QFE should be carefully set because it may influence the impact point calculation. If the computer thinks ground level is higher than it actually is, you might overshoot your target (see image).

Else, you might hit right before the target (as if, in the image, the target and dark line were above the red line while the orange line stays in the same position. The impact point would then be to the right of the target).

I found out this happens more often with rockets.

QFE should be carefully set because it may influence the impact point calculation. If the computer thinks ground level is higher than it actually is, you might overshoot your target (see image).

 

 

Else, you might hit right before the target (as if, in the image, the target and dark line were above the red line while the orange line stays in the same position. The impact point would then be to the right of the target).

 

I found out this happens more often with rockets.

Please view track files. All QFE settings are correct and aim points selected with AGR ranging active. Another user independently verified my results.

yep, it's still happens unfortunately, regardless how I calculate and set QFE

I watched your first track. I noticed you pulled the trigger to the first detent while having the dot right on the target. But, you released it. And then pulled it again, a few dozen meters before the target. That's when you went from first detent to weapon release. The computer calculated the impact point where you designator dot was when you pulled the trigger to the first detent the second time.

What you should do is : aim at the target, pull trigger to first detent. Hold it there until you get the fire cue on the HUD. Afterwards, you will see the ring go up, it means you have to pull the stick for a 4G climb. This is how the computer spreads the bombs at the interval you selected on the weapon interval selector.

Not convinced. I did a video to show it:

Note I did not even bother configuring the QFE on the altimeter.

Edit: I also disabled target motion measurement (TAKT IN 221)

I did try the toss bombing method. 4 out 4 times, I got the target in the middle of the bomb run. 3 out of 4 times, the bombs did land before and after the target and only damaged it (the target was in the interval between the bombs). 1 time, one of the bombs directly hit the target.

See video here:

The issue with what I see on track 7 is that you are not following the procedure for toss bombing. Please check the manual on page 313.

Also note, toss bombing is heavily dependent on the accuracy of your INS. You have to make sure TERNAV has compensated for the INS drift before release the bombs. If you're on flat terrain, you'll have to do an INS fix using some terrain feature.

I watched your first track. I noticed you pulled the trigger to the first detent while having the dot right on the target. But, you released it. And then pulled it again, a few dozen meters before the target. That's when you went from first detent to weapon release. The computer calculated the impact point where you designator dot was when you pulled the trigger to the first detent the second time.

 

What you should do is : aim at the target, pull trigger to first detent. Hold it there until you get the fire cue on the HUD. Afterwards, you will see the ring go up, it means you have to pull the stick for a 4G climb. This is how the computer spreads the bombs at the interval you selected on the weapon interval selector.

 

Not convinced. I did a video to show it:

 

Note I did not even bother configuring the QFE on the altimeter.

 

Edit: I also disabled target motion measurement (TAKT IN 221)

You have DYK and PLAN confused. The ring in PLAN release is a steering order to maintain lateral attitude and the safety altitude. Shouldn't be any g involved.Please read the documentation. The ring in DYK commands a 4g climb at release. You don't need to pull G to separate the bombs in a level release because you are traveling, well, level.

Also, if I designated a few meters in front of the target, why did the WHOLE string miss?

How come if I PURPOSELY designate a spot past the target (any target), I can hit dead center?

You also never adjusted QFE, which is odd, because in your first post that is the reason you told me why I missed, which leads me to believe you weren't certain how this system worked at first. Of course, QFE only affects pre-designation symbology if radar ranging is used for the designation, it wouldn't effect bomb accuracy is AGR is used.

Also, see further evidence of NAV mode and RR mode, both landing short the exactly the same way. Also see Random's post on bombing the runway threshold where he was able to repeat my results using something that isn't as finnicky as an ammo dump to target.

Also, I never said toss bombing was inaccurate. Actually, I think the recent changes to toss bombing that made it accurate are what broke these other modes. It's like if you're not pulling G at release you land short. In fact, I'm not sure what you're talking about. I never posted a track demonstrating toss bombing in this thread at all. NAV mode isn't just for toss bombing, you CAN do toss bombing in that mode, but it isn't necessary. Is that what you're talking about?

Target motion measurement is off by default, has been I think since an update early summer of 2019 or so.

Again, I cannot stress enough that up until the update 2 updates ago, I HAD 0 PROBLEMS WITH ANY OF THESE MODES FOR 2 YEARS. Only when tossing in NAV, wherein the bombs would always land long. Now, toss doesn't land long, and everything else lands short. Could be a coincidence, but this is definitely a bug.

I will conduct additional tests tonight. I wonder if the system doesn't work unless you're pulling G? Tonight, I will posts tracks showing purposely designating long, then a track pulling G at release, then I will target something flat, like a runway to eliminate designation as a factor.

Do you have a track of this video you posted? Random and I both found it a bit deceiving where you designate if you can't zoom in on the HUD in a track.

EDIT: Here's a video from 7 months ago, start at about 2min. As you can see, no g pulled, using the steering order to maintain attitude, same designation spot, bombs bang on.

Fair enough, I think it's up to RagnarDa to clarify

Thanks for all the reports!

I am happy to say that I finally finished implementing and integrating the custom bombing solution that was started in this stream: https://forums.eagle.ru/showthread.php?t=259071

While integrating this I discovered a old bug where the air density (which is supposed to be set by ground crew) was not changed and always had a default value. This would lead to slightly inaccurate airspeed readings.

Using the new ballistics calculations I had very accurate results, better than with the old way. I even downloaded a track posted in this thread and even though the description said the bombs fell short when replying it now the bombs went on target. Probably needs a bit more testing but I am quite excited to maybe finally being able to put this issue to rest.

:thumbup:

you guys rock!

Cool!

I am happy you found the other bug too! :joystick:

Thanks for all the reports!

 

I am happy to say that I finally finished implementing and integrating the custom bombing solution that was started in this stream: https://forums.eagle.ru/showthread.php?t=259071

 

While integrating this I discovered a old bug where the air density (which is supposed to be set by ground crew) was not changed and always had a default value. This would lead to slightly inaccurate airspeed readings.

 

Using the new ballistics calculations I had very accurate results, better than with the old way. I even downloaded a track posted in this thread and even though the description said the bombs fell short when replying it now the bombs went on target. Probably needs a bit more testing but I am quite excited to maybe finally being able to put this issue to rest.

VERY cool! Thanks for all your hard work.

You have DYK and PLAN confused. The ring in PLAN release is a steering order to maintain lateral attitude and the safety altitude. Shouldn't be any g involved.Please read the documentation. The ring in DYK commands a 4g climb at release. You don't need to pull G to separate the bombs in a level release because you are traveling, well, level.

 

Also, if I designated a few meters in front of the target, why did the WHOLE string miss?

 

How come if I PURPOSELY designate a spot past the target (any target), I can hit dead center?

 

You also never adjusted QFE, which is odd, because in your first post that is the reason you told me why I missed, which leads me to believe you weren't certain how this system worked at first. Of course, QFE only affects pre-designation symbology if radar ranging is used for the designation, it wouldn't effect bomb accuracy is AGR is used.

 

Also, see further evidence of NAV mode and RR mode, both landing short the exactly the same way. Also see Random's post on bombing the runway threshold where he was able to repeat my results using something that isn't as finnicky as an ammo dump to target.

 

Also, I never said toss bombing was inaccurate. Actually, I think the recent changes to toss bombing that made it accurate are what broke these other modes. It's like if you're not pulling G at release you land short. In fact, I'm not sure what you're talking about. I never posted a track demonstrating toss bombing in this thread at all. NAV mode isn't just for toss bombing, you CAN do toss bombing in that mode, but it isn't necessary. Is that what you're talking about?

 

Target motion measurement is off by default, has been I think since an update early summer of 2019 or so.

 

Again, I cannot stress enough that up until the update 2 updates ago, I HAD 0 PROBLEMS WITH ANY OF THESE MODES FOR 2 YEARS. Only when tossing in NAV, wherein the bombs would always land long. Now, toss doesn't land long, and everything else lands short. Could be a coincidence, but this is definitely a bug.

 

I will conduct additional tests tonight. I wonder if the system doesn't work unless you're pulling G? Tonight, I will posts tracks showing purposely designating long, then a track pulling G at release, then I will target something flat, like a runway to eliminate designation as a factor.

 

Do you have a track of this video you posted? Random and I both found it a bit deceiving where you designate if you can't zoom in on the HUD in a track.

 

EDIT: Here's a video from 7 months ago, start at about 2min. As you can see, no g pulled, using the steering order to maintain attitude, same designation spot, bombs bang on.

Hi Rifle,

I did exactly as you do and the bombs did indeed fall short. Now I am puzzled as I don't know anymore how I put them on target like just a few days before! I think one of the issues is the safety altitude because on the last video I dropped the bombs from 400+m and this time from an altitude of 200m. I'm not sure how or if it is related to the air density bug Ragnar is talking about?

Just did a few trials and the results are inconsistent. I can put the bombs on target about 35% percent of the time. I tried at different altitudes from 200m, 250m to 400m at the moment of release. It's not a matter of altitude.

Following the yellow needles on the ADI does not influence the results so far obtained.

The only way to almost consistently put the bombs on the target is to raise the nose of the plane while dropping them.

Posted one of the trks of a successful run at the target.

bombs_short1_SafeAltLowSuccess.trk

Just did a few trials and the results are inconsistent. I can put the bombs on target about 35% percent of the time. I tried at different altitudes from 200m, 250m to 400m at the moment of release. It's not a matter of altitude.

 

Following the yellow needles on the ADI does not influence the results so far obtained.

 

The only way to almost consistently put the bombs on the target is to raise the nose of the plane while dropping them.

 

Posted one of the trks of a successful run at the target.

See Ragnar's post above. It's a confirmed bug that has been fixed. I assume it'll be released in the next OB patch, whenever that is.

I believe the reason you're hitting is because the logic of the designation may have changed to match the real aircraft. The designation point you deliver the bombs on is the point where trigger is held (so there is in essence two designations, one on unsafe, another on trigger held). This would match the behavior of DYK mode.

If that is the case (I need to test more to see if it is), then it makes sense you hit in the video you posted. Attached is a picture of your pipper when you went trigger hold.

I'll have to test a bunch tonight!