CCRP bombing

[svetron]

Hi !
I've been wondering about how CCRP bombing works.
Can you bomb just on coordinates, or do you need a radar lock?
If you bomb just on coordinates, how accurate would that be? (with dumb bombs)
Last thing - presuming you can bomb on coordinates - when or why would you use that kind of attack.

[HazF16]

you dont need a radar lock to use CCRP. if you got some coordinates you can set a new STPT using those coordinates and just place the CCRP TD box in the HUD on the STPT diamond (or wherever you want to drop) when approaching the target. to answer your last question, I think this method would be used for fixed targets such as buildings or whenever you gotta visual ID the target (for example dive bombing w/ dumb bombs).

I think we can't discuss the accurancy of the guidance system of the Viper in here.

[Vipertrunk]

CCRP is used for several reasons with both "dumb" and precision weapons. The previous post is correct, there is no lock required for a CCRP delivery. However, the accuracy of the drop could be improved by a radar or targeting-pod track (or update) on a known terrain feature (a road intersection with known bearing and range to the target - for example)

CCRP with dumb bombs would probably be used as a weather backup. You cannot bomb visually if you can't see the ground, so a system delivery is better than landing with the bombs.

For difficult to identify targets (under camouflage netting or in a wooded area - for example) many pilots will begin a visual delivery with CCRP selected and then switch to CCIP or another mode once the target is identified. CCRP puts a TD container over the target coordinates and guides the pilot's eyes to the correct target.

As to the accuracy - well, as with everything - it depends. How good are your target coordinates? How "tight" is the navigation system? The actual winds need to match with what the jet "thinks" the winds are. The jet has a wind model that estimates surface winds based on the winds calculated from the INS for the current altitude. If that doesn't match reality (wind shear for example) then your bombs will miss. Finally - and probably the biggest factor - what is your distance from the target? Even if everything is as perfect as it can be - small errors add up to large miss distances and these effects are magnified the further away you get.

For example - on a diving CCIP delivery (45 degree dive bomb for example) - if the pilot misplaces the pipper by 2 mils (the width of the pipper dot) the bombs will miss by 120 feet(assuming a slant range of about 6000' at release). This is due to a small pointing error propagating over a large distance. The same thing is true for a CCRP delivery. A level pass at 500' AGL will probably be pretty accurate - even with small errors. At 30K' AGL those same small errors will result in a wide miss.

I've seen enough CCRP deliveries score direct hits - even from medium altitude - to know that it's pretty darn good though.

[hansundfranz]

If you bomb just on coordinates, how accurate would that be? (with dumb bombs)

Depends on the wind at lower altitudes, the delievey altitude and release angle. Also depends on how precise the aircrafts position is known (pretty precise now ith GPS recievers)

You can expect to hit relatively large buildings somewhere but you can´t expect to drop it right into a ventilation chimney.

Last thing - presuming you can bomb on coordinates - when or why would you use that kind of attack.

- If you have no PGM for some reason
- if clouds or thick smoke prevent that you see the target
- if the target is so large that precission does not matter to much and you want to minimze risks
- if you can´t see your target with the radar,
- if your GPS coordinates are nice and precise

Numbers: http://www.globalsecurity.org/military/ ... -bombs.htm Check the table in the end

[Roscoe]

I'll add that when ground fire is a concern, one may not want to dive into the target (CCIP) so CCRP may be a better (safer) tactical option.

[Gums]

Yo Ho!

Previous poster is correct - no need to "designate" the CCRP tgt (last Block Avionics I checked). Sucker will drop on the "tgt coordinates" you loaded. Good nav updates will help, but with the GPS in the nav solution, I wouldn't worry too much.

Secondly, please quit worrying about wind! If you are droppping from 20,000 friggin' feet, you might miss a few meters with a low-drag bomb. Imagine a 2,000 pound bowling ball pushed off of a 5 mile high building. How much do you think the thing will move horizontally in a 20 or 30 mph wind? High drag weapons ( like my favorite parachute-retarded nuke-u-lar types) will certainly have trouble in changing winds, but the basic bomb solution is based upon actual movement of the jet with respect to the tgt and the earth. The drag of the weapon causees it to "slow down" as it falls, so we have "trail" distance in the airmass. At low alt releases, such "trail" was about two feet! i.e., the bomb went off right below you, regardless of the delta between flight path over the ground and the airmass flight vector.

In the really old days, wind was a biggie. The nav gear didn't provide actual movement/vectors with respect to the earth/tgt. So our impact point was calculated for the airmass coordinate system. By cranking in the movement of the airmass (read "the wind"), we might get close. I dropped thousands of dumb boms, folks. I did so using the best computed systems existant, and I dropped many thousands using the Mk 1/Mod 0 eyeball. Without the computer, I simply flew my butt over the tgt, even if the nose was pointed 20 degrees to the side. Guess what? The bombs hit along my ground track, and it was up to me to guesstimate when to pickle for the range. For one 3-month period in a certain plane I averaged less than 30 feet miss distance dropping dumb bombs from 2,000 to 3,000 feet in a 30 deg dive. And there were another 4 or 5 troops in the squad that did as well.

later,

[hansundfranz]

Secondly, please quit worrying about wind! If you are droppping from 20,000 friggin' feet, you might miss a few meters with a low-drag bomb.

Yeah that must be the reason why the WCMD guidance kit was developed?

What´s the TOF for a bomb from a 20,000 ft level delivery? 35 seconds without takeing any drag into acount. In Real quite a bit longer, so plenty of time for even relatively weak unexpected winds to move the bomb to the side.
Of course precission is relative and on many targets a pretty wide miss with a Mk84 still destroys it

[svetron]

Thanks for the "on the mark" answers guys !

[Obi_Offiah]

Secondly, please quit worrying about wind! If you are droppping from 20,000 friggin' feet, you might miss a few meters with a low-drag bomb.

Yeah that must be the reason why the WCMD guidance kit was developed?

What´s the TOF for a bomb from a 20,000 ft level delivery? 35 seconds without takeing any drag into acount. In Real quite a bit longer, so plenty of time for even relatively weak unexpected winds to move the bomb to the side.
Of course precission is relative and on many targets a pretty wide miss with a Mk84 still destroys it

Hi hansundfranz.

The MK-84 & SUU-64/65 Tactical Munitions Dispensers are quite different aerodynamically. The MK-84 is a slick low drag weapon, the TMDs which the WCMD kit is used in conjunction with are far more 'draggy' and thus I would presume effected by winds to a greater extent. Also the nature of the pop-out fins on the TMDs may aggravate the weapons susceptibility to the effects of wind, as its fins were designed to meet different criteria to a low drag general purpose bomb.

Obi

[Gums]

Salute!

Obi is correct, Hans.

With the limp d(&^% commanders having folks drop from the ionosphere, the drag of the dispenser will, indeed' result in a far greater "trail" distance. We are talking about tens of feet, not hundreds of feet.

Nevertheless, someone sold the USAF on a "wind-corrected" dispenser. Just so happens that I was on the losing team for the thing - Textron, who makes the SFW. I even developed the simulator for the initialization of the thing using F-16 Block 40 avionics.

So I saw the aero capabilities of their dispenser, which used GPS, much like the JDAM. In fact, the JDAM (which I also worked on) guidance kit was overkill for the WCMD. The problem was that a new aero package had to be developed for the dispenser due to form factor constraints. So you basically had a JDAM dispenser - new fins and control surface power system, etc.

Deep down inside, I think the guys that wrote the Ops Requirement really wanted a new kit to place on the SFW and other submunitions that fit inside the basic dispenser. They used the word "wind" so the stupid politicians approving the $$$ could understand.

The thing that impressed me was the off-axis capability of the Textron doofer. That sucker could turn over 90 degrees from release heading and hit something way way out there when released from 20K.

With the new kits, and they are really cheap, I think wind is something that only we old dinosaurs used to worry about and practice for.

out,

[elp]

Great reading as always Gums. One of my favorite videos is that Textron SFW BLU-108B in a CBU-105 vid. Best killer of AFVs out in the open. Dead meat.

[hansundfranz]

Hi hansundfranz.

The MK-84 & SUU-64/65 Tactical Munitions Dispensers are quite different aerodynamically. The MK-84 is a slick low drag weapon, the TMDs which the WCMD kit is used in conjunction with are far more 'draggy'

I know, just wanted to rock the boat a bit

From wikipedia http://en.wikipedia.org/wiki/JDAM

JDAM system will provide a weapon circular error probable of 13 meters or less (some Boeing sources report less than 10 meters CEP) during free flight when GPS data is available. If GPS data is denied, the JDAM will achieve a 30 meter CEP or less for free flight times up to 100 seconds with a GPS quality handoff from the aircraft.

A JDAM without GPS DATA is basically a wind corrected MK84. No one knows how correct thart DATA is but nevertheless it is interesting

[Roscoe]

Great reading as always Gums. One of my favorite videos is that Textron SFW BLU-108B in a CBU-105 vid. Best killer of AFVs out in the open. Dead meat.

Wow...like, acid flashback man. (Watching E-Ring right now and got that Dennis Hopper thing going )

I was one of the early test engineers on SFW back in 84-85. Took several SDVs out to Kirtland/Sandia and blasted apart some T-62s and M-47s with the little suckers using the cable pull down facility. Now THAT was fun.

[elp]

From wikipedia http://en.wikipedia.org/wiki/JDAM

JDAM system will provide a weapon circular error probable of 13 meters or less (some Boeing sources report less than 10 meters CEP) during free flight when GPS data is available. If GPS data is denied, the JDAM will achieve a 30 meter CEP or less for free flight times up to 100 seconds with a GPS quality handoff from the aircraft.

The 30 meter CEP is a reach. Not even close. Boeing....in public consumption testing ( look at all their press releases on JDAM ) has already shown that a JDAM flying through 100 mph windshear dropped from 30+ K ft in a GPS "jammed" environ wasn't much different than one that aquired the GPS signal more like a sub 8 meter CEP 100 seconds doesn't provide enough risk to the on board INS of not knowing where it is. Flight times from 40k ft are closer to 60+ seconds ( this all depends on distance of course ). The point being that INS drift becomes more important ( needing updates ) with longer fly time weapons like JSOW, JAASM or SDB on a long long glide. Certainly more critical with SDB because of the small warhead. A 2000lb class iron weapon being 8 meters give-or-take off will still kill a bunch of targets.

Two. Our miltary GPS tech is wayyyy more secure than what the general public knows. Way more. It is a method with a secure topology and a lot of anti-spoofing measures.

The most irritating thing is watching some moron from the Brookings Institution or some other dork "think-tank" person that has never seen any of this junk first hand or talked to the people that work on it, spread BS that the JDAM will be 30 meter CEP if it doesn't aquire the signal. If it is that far off, something on the weapon kit failed or a poor quality target coordinate was pumped into it.

[hansundfranz]

Two. Our miltary GPS tech is wayyyy more secure than what the general public knows. Way more. It is a method with a secure topology and a lot of anti-spoofing measures.

It is still ony a very low powered signal (max 50W) transmitted from far away (over 35.000 km) and that makes it easy to drown the signal with very simple jamming techniques