Dropping Iron Bombs - How to calculate the impact point?

In the A-10 the aircraft does all the hard work for us. Dumb bombs - no problem, thanks to CCIP mode!

But how can one approach this problem if there is no CCIP is available? For example with all the trainer/light attack aircraft that we have and which usually only feature a rather simplistic gun sight.

I have a rough idea which components go into a forumla that allows to calculate the impact point. Mass of the ordnance, drag of the ordnance, speed of the delivery, height over target, slant angle of delivery, ballistic trajectory - all that and somehow we get a value for adjusting the depressable pipper.

But how does the formua actually look like? The guys of 476th certainly use something that allows to calculate those Z-sleds - which are quite nice for itself - but those do not really help with other aircraft and/or weapons.

If someone could enlighten me here a bit, I'd be gratefull. But please in rather simple terms ... I tried to get a grip on the explanations of the calculations of the ballistic trajectory at wikipedia ... but ... erm, yeah. ;o)

AFAIK, on those old aircraft ( or aircraft with simple targeting system) that information would be on the manuals. So the pilots would know that for bomb type "A" (just and example) dive angle would be "X", speed should be around "Y" etc. The only thing we could do is test on the game or look online and find similar document that might give us an approximation or a place to start.

Document like this one might help get some (but obviously not all) information. This is a direct PDF link.

Drag Characteristics of MK-82

Supersonic delivery of conventional weapons

Another PDF link

Operational Suitability test of the F-86F aircraft

The problems is I'm not sure how much of it will relate to DCS.

If this helps, I can keep looking.

PS

On modern aircraft, like a F-16, etc, I do not think the pilot would attempt to drop weapons if the CCIP/ CCRP was inoperable. Not sure if they even train to deliver weapons manually.

I am sure someone has probably tried and tested manual weapons delivery in DCS, we just need to find the post or link somewhere.

There are specific bombing procedures for those aircrafts without CCIP, with recomended speed, height and descent angle and aiming point of the bomb release. But, you know, the accuracy cant be compared to the CCIP/CCRP, there is a lot of training needed.

See for example WWII fighters or MiG-15 manual.

@mvsgas: thanks, some interesting read - nevertheless

@suchacz: yes, I know, but how did those reccomendations and procedures get into the manuals? Or how does the computer compute CCIP`?

The theory behind it all is and was understood quite well, I assume, even before WWII, as some of i.e. msvgas' documents suggest. Back then they just had no means to implement this knowledge into usable hardware.

I want to compile such tables that should be found in the manuals by myself. But not with hundreds or thousand test runs - but by calculating it. Or at least, calculating a good starting point for further tests and refinements.

@mvsgas: thanks, some interesting read - nevertheless.

Sorry I could be of much help

@suchacz: yes, I know, but how did those reccomendations and procedures get into the manuals? Or how does the computer compute CCIP`?.

Not directed at me but, AFAIK, by doing hundreds or test. Bomb separation, captive test, different configurations, etc, etc.

For example:

PVkqrkA8KnU

I want to compile such tables that should be found in the manuals by myself. But not with hundreds or thousand test runs - but by calculating it. Or at least, calculating a good starting point for further tests and refinements.

I would guess you, at a minimum, would need to know how each weapons behaves within the DCS.

I tried to get a grip on the explanations of the calculations of the ballistic trajectory at wikipedia ... but ... erm, yeah. ;o)

I imagine Wiki would be pretty good for this. You'll need a spreadsheet at least, drag takes something simple and makes it more of a pain than it should be. Without drag initial conditions and gravity are enough. Unfortunately, you can't factor in the drag accurate by adding a term to an equation. You need to account for drag at every instant in flight. Computers can't do that, so instead you break up bomb trajectory into very small steps of time and apply constant forces for those steps of time.

There are specific bombing procedures for those aircrafts without CCIP, with recomended speed, height and descent angle and aiming point of the bomb release. But, you know, the accuracy cant be compared to the CCIP/CCRP, there is a lot of training needed.

Believe it or not, real modern pilots fly their aircraft basically by those same parameters, with CCIP only allowing them to more easily salvage a poor pass. Even so, those parameters don't exist purely for delivery of a bomb on target, but also for factors such as frag avoidance. CCIP profiles are programmed to allow a pilot to meet things like the frag avoidance parameters based on TOF of the bomb and the only reliable way to do that safely is to fly a predictable path. The big difference in the modern world is that rather than using fudged compensations for being off the wire you instead use CCIP cues to adjust your dive bomb attack.

The same calculator that produced the 476th charts produces an additional figure thats used for using the depressible pipper for manual bombing. Therefore the parameters for flying a CCIP delivery and a manual one are basically the same.

[quotePS

On modern aircraft, like a F-16, etc, I do not think the pilot would attempt to drop weapons if the CCIP/ CCRP was inoperable. Not sure if they even train to deliver weapons manually.

A-10s pilots train with "degraded" systems, meaning manual delivery, often. Can't speak for 16s or 15E's though.

Did not know, thanks

How about loft bombing?

I researched it a bit because it sounds like a fun way to deliver ordinance. Especially the 25T would benefit from this. But calculating the release point of bombs during a loft is either a lot of practice or pure luck.

How about loft bombing?

I researched it a bit because it sounds like a fun way to deliver ordinance. Especially the 25T would benefit from this. But calculating the release point of bombs during a loft is either a lot of practice or pure luck.

I developed a software (for myself) not so long ago that would compute the point to aim on the visor of an il-2 to hit a target with an iron bomb. I only considered the initial parameters of the delivery (the attitude of the plane) in the computation. However for short time of flight it is reasonably accurate. I would very much like adding drag coefficient to my calculations but they are hard to find for WWII ordnance.

I don't think loft bombing is a good idea in th Su-25T because it really lack the speed and the agility to those maneuvers. In an F-16 I pull 4/5g to loft my bombs and I thing the Su-25t would take so much incidence from this it would just stall. However I don't have much knowledge on aerodynamic or on the Su-25T so it is just a guess.

I developed a software (for myself) not so long ago that would compute the point to aim on the visor of an il-2 to hit a target with an iron bomb. I only considered the initial parameters of the delivery (the attitude of the plane) in the computation. However for short time of flight it is reasonably accurate. I would very much like adding drag coefficient to my calculations but they are hard to find for WWII ordnance.

Try a Cd of 0.3 or so- should be pretty close for a WW2 General purpose bomb.

Try a Cd of 0.3 or so- should be pretty close for a WW2 General purpose bomb.

Thank you, I will implement that when I will have time.

Your best friend would be tacview.

OK, here is a thought:

Create a free bombing mission with zero winds, CAVOK meteo. Fly it and drop bombs in regular fashion dont worry about missing. Now exit and save track.

In tacview open it and save the cockpit view on a fraps recording. Now open dcs, run the track but distort the view so that view is only on HUD or a known reference with zero shaking or G-loading effects (preferably turn these off).

Record that in fraps, then using both tacview recording and track recording, open a video editor and place both files on timeline.

Now set one as overlay (I use serif movieplus X5), and match track time to tacview time so movements are syncd. Export that movie and note the usual:

1- starting altitude

2- starting speed

3- g-load

4- base distance

5- roll in pitch and bank angle

6- aim off distance (you can set a soldier with smoke in mission to be your reference in X and Y plane).

now set these parameters as a baseline. Fire up mission and repeat using these parameters. Now check tacview and adjust.

tacview should really be useful when Vyrtuouz implements real time telemetry, where on a screen on your laptop, you can check parameters as you fly.

F16 has a manual bombing mode. Redundancy I guess