Bombs accuracy direct & DT

[markturner1960]

I am very happy to accept this is down to user error, but I am fairly well practiced in dumb bomb delivery in the F5, F14, AV8B and F18, and can achieve pretty good results in these platforms.

I have spent maybe a coupel of hours trying both direct and DT modes in the F4 with awful results. I am using the dive computer and inputting the correct variables, While my parameters may not be perfect I am sure they are not that bad... in direct mode, my bombs seem to fall consistently about 500 metres short, in quite repeatable pattern. In DT its similar.

What may be causing this and any tips? I have watched the guides on YT....

[MBot]

Don't trust the Bombing Table for mils values in Direct, they are not calculated correctly. Better fly the attack profile you intend to use, hit Active Pause when you are in parameters, drop a bomb and dial the sight to the mils where your observe the impact. Use that mils value from then on.

[markturner1960]

Thx, will try that, although tricky in multiplayer......I just did a sortie and looked on tacview, my parameters were pretty off as well, so thats not helping....funny how in the jet you think you being way better in sticking to parameters than you actually are! 

[BJ55]

You must fly the parameters with precision, but before you must find suitable parameters for the mission profile.

I've did some tests with the DT training mission and both DT and Direct gave me good results (400kts, 3000ft, 30°) .

Question: since bombing tables (kneeboard) have notes regarding the corrections needed for pressure and temperature deviation, does DCS weapons simulation take in account those parameters?

[skywalker22]

With a DT mode, I actually never missed so far 10/10. Its pretty easy, you just have to make sure to be inside all parameters.

Starting at cca 12-13k ft, diving down at 30deg and release as specified in the bomb table (I did 2500-3500ft and all bombs got to the exact point).

[eifionglyn]

When it was first released, I was able to hit the target reliably with Mk82s in DT mode. However since the latest patch they are now dropping consistently short. I notice the bombing table calculator is now showing some different fields than it did before so something has changed.

[some1]

I also noticed something has changed after the latest patch. I need different mils values for gun and rockets, and also didn't have much luck with DT yesterday.

[primus_TR]

For the direct mode, the bombing calculator report mils about 20 more than it should. Could be non linear, so take that with a  pinch of salt. If the calc says 120, I set it to 100. Usually works. 

But why not use dive toss instead? If you can keep the reticle steady on the target until radar lock is achieved,  and not pull up and maintain the dive angle and wings level when pickling, 99% of the time you'll score a hit.  

[Zabuzard]

The most frequent user mistake I see is people flying the wrong airspeed, as they look at the IAS and not TAS gauge.

[AvroLanc]

1 hour ago, Zabuzard said:

The most frequent user mistake I see is people flying the wrong airspeed, as they look at the IAS and not TAS gauge.

This is undoubtedly true. But I wonder if the ED ballistics is just a little too sensitive for TAS. I’m finding in particular that high drag bombs are EXTREMELY sensitive to errors in TAS and even a 5–10 knot difference from planned throws Snakeeyes and Ballutes significantly long or short. 
 

[paura19]

Only DT works for me.

Direct and LayDown are not accurate with bombing table. 

Laydown 450TAS 500ft = bombs fall 300-400ft long 
F4 82snk LyaD 450 500 .trkF4 82 LyaD 450 500 .trk

I will try the setup like MBOT. 

[MBot]

7 hours ago, primus_TR said:

But why not use dive toss instead? If you can keep the reticle steady on the target until radar lock is achieved,  and not pull up and maintain the dive angle and wings level when pickling, 99% of the time you'll score a hit.  

I just tried 3 Rockeye drops in DT and they all landed short. I am pretty sure that the drag coefficient for Mk-20 in the Bombing Table is for the canister only. The problem is that when the bomb opens (the time-point being dependent on the fuze setting), the drag coefficient for the bomblets would be much higher. Since this is not considered in DT they land short.

On the other hand I get excellent results for Rockeyes in Direct with my own mils value:

 

And scoring hits in Direct is just so much more satisfying But I agree in practice there is little reason not to use DT, at least for slick bombs. There radar lock can usually be done quick enough so that it is doable also in pop-up attacks.

Still, nothing beats the pure fun of Direct

 

[bonux1987]

16 hours ago, Zabuzard said:

The most frequent user mistake I see is people flying the wrong airspeed, as they look at the IAS and not TAS gauge.

This is going to be a stupid question, but i've been looking at the manual, but could someone point me out how to see the IAS speed gauge and where to see the TAS speed gauge ?
Sorry for this noobish question, but i'm not home and i want to know it  

[Marsvinet]

1 hour ago, bonux1987 said:

This is going to be a stupid question, but i've been looking at the manual, but could someone point me out how to see the IAS speed gauge and where to see the TAS speed gauge ?
Sorry for this noobish question, but i'm not home and i want to know it  

The IAS gauge is the one just left and above of the ADI, which shows your airspeed in knots and mach. Hidden near the top left of the front panel, behind and to the left of the RADAR/HEAT/GUN indicator is the TAS gauge, which shows your TAS on a roller indicator. 

[bonux1987]

5 minutes ago, Marsvinet said:

The IAS gauge is the one just left and above of the ADI, which shows your airspeed in knots and mach. Hidden near the top left of the front panel, behind and to the left of the RADAR/HEAT/GUN indicator is the TAS gauge, which shows your TAS on a roller indicator. 

Thank you so much ! May you be blesses with kindness in return today !

[IvanK]

In most 2/3rd Gen aircraft in manual bombing you decide on the release CAS,Dive Angle altitude/height. You then compute the associated TAS. You then enter the ballistics tables with those criteria to determine the Mills depression, From that point on TAS is irrelevant.

You then in the jet drop on indicated values i.e. Alt,IAS/CAS not TAS.

In the case of the F4E you are served a double Whamy. A non pilot friendly ASI with tiny IAS scale but huge Mach number scale (quite the opposite to most western fighters), and a TAS gauge that is bordering on impossible to see.

 

[paura19]

@MBot still your data: 55MILS -15° 0,8M  is the most accurate bombing setup. Mk82, 83, 84.

Bomb table calculates 90MILS+ 

Edited July 13, 2024 by paura19

[Kalasnkova74]

What may not be helping matters are canted outboard bomb racks. This does not appear to affect the outboard fuel tanks. Perhaps a bug?

 

[Kirk66]

The bug is that the fuel tank pylons for the 370 tanks should be a part of the tank, and not remain on the jet when you drop the tanks. Those are vertical. The wing outboard weapons pylons are a different item, which may well be canted a bit (we never used those much).

But that should not have much (if any) impact on dropping bombs.

Vulture

[Kalasnkova74]

2 hours ago, Kirk66 said:

The bug is that the fuel tank pylons for the 370 tanks should be a part of the tank, and not remain on the jet when you drop the tanks. Those are vertical. The wing outboard weapons pylons are a different item, which may well be canted a bit (we never used those much).

But that should not have much (if any) impact on dropping bombs.

Vulture

Thanks. 
False alarm on the bug note. Apparently the MER doesn’t clear the landing gear in a purely vertical configuration.  USAF F-4s and USN F-4s solved the problem in different ways. 
 

According to the source below, the USN kept the vertical pylons and canted the MER using an adapter. 
 

The USAF fixed the clearance issue by canting the entire pylon, so HBs presentation is 100% accurate. 
 

https://tailspintopics.blogspot.com/2016/01/f-4-phantom-outboard-pylon-and-mer.html

[Kirk66]

And for the true MK82 (and BDU-33) afficionados, there are even charts for the dispersion caused by the shoulder positions of weapons on MERs and TERs - due to the "push" from the ejector carts kicking the bomb off the rack and away from the jet. Pre-DMAS this just resulted in a bigger CEP when dropping bombs from the F-4, but with the DMAS kit you could actually input a correction into the system for each store position. But this had to be done prior to each pass, dropping a single bomb, and you had to know what station on the MER/TER the bomb was going to be released from, what kind of bomb, what kind of delivery, etc and plug in the numbers prior to the pass. Lots of fun in the pop pattern, typing into the computer while upside down and pulling a few G's, just to win a few quarters.

Edited July 14, 2024 by Kirk66
clarity

[Kirk66]

On 6/11/2024 at 5:14 PM, IvanK said:

In most 2/3rd Gen aircraft in manual bombing you decide on the release CAS,Dive Angle altitude/height. You then compute the associated TAS. You then enter the ballistics tables with those criteria to determine the Mills depression, From that point on TAS is irrelevant.

You then in the jet drop on indicated values i.e. Alt,IAS/CAS not TAS.

In the case of the F4E you are served a double Whamy. A non pilot friendly ASI with tiny IAS scale but huge Mach number scale (quite the opposite to most western fighters), and a TAS gauge that is bordering on impossible to see.

 

Well, you do have the advantage of a verbal airspeed indicator in the back seat. 

[IvanK]

13 hours ago, Kirk66 said:

Well, you do have the advantage of a verbal airspeed indicator in the back seat. 

Yes The pain of carrying a Navigator !

[Kirk66]

"Pilot, where the hell are we? I'm the Navigator and I have a RIGHT to know!"

 

[LastRifleRound]

The biggest reason for misses using DT is not being wings level when first hitting pickle. If you're not wings level when pickling, you'll "throw" the bombs crooked if you maintain that attitude through the release. If you are not wings level when first hitting pickle, then roll wings level as you pull up, you'll put the bombs in a straight line beside the target.

Easiest way to get hits is largely ignore parameters (they're not really needed), make sure your dive angle is 30 degrees or greater (makes radar lock faster and the reticle move slower relative to the ground), and make sure wings are level just before pickling then all the way through.