F-16.net

F-16.net Editor Joined: Sep 23, 2003 Posts: 2848

Here is some very loose text of the update to the JDAM page on <a href="f-16_armament.html">the armament section</a> of F-16.net which will correct some things. I need a real munitions troop to review it for accuracy. This is your site and the words should be bulletproof.

Note:
The write up is done in the following fashion.
*At the public consumption level and yes there are some obvious things left out. Laughing

*I am mentioning only the JDAMs that are currently fielded by todays F-16s. i.e. no GBU-32s at this time ( unless someone can show a pic or writeup saying they are in use by F-16s... ) fielded for the troops not everything under the sun that was tested.
*I don't have the physical weight/dimensions of the BLU-109 JDAM GBU-31(V)3/B setup. As the 31(v)1/b and GBU-38 are mentioned. We should show the 109 too or exclude all three dimensions.

Also in the similar weapons section, I need to add the new Chinese GPS assisted dumb iron kit. Anyone with the nomenclature on that??

So if any munitions peeps see any gross errors here, please comment.Again your input will make the page look good. After we get done with this I will do one up on Laser Guided Bomb kits.

Thanks in advance!

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Introduction

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An inert 2000lb GBU-31 JDAM on the number 3 station of a USAF F-16. (USAF photo)
===

The Joint Direct Attack Munition (JDAM) is a guidance tail kit that converts existing unguided free-fall bombs into accurate, all-weather guided bombs. The JDAM kit consists of a new tail section containing an inertial navigational system (INS) and a global positioning system (GPS) guidance control unit. JDAM can be launched from approximately 15 miles from the target and each is independently targeted. JDAM was jointly developed by the U.S. Air Force and U.S. Navy, is built by Boeing, and can be fitted to the standard Mk.80 series of free-fall bombs. Each kit costs around $18,000 (USD).

History

In the early 1990s, operation Desert Storm saw the first widespread deployment of smart bombs. The smart weapons used during Gulf War I were mainly Laser Guided Bombs (LGBs), i.e. standard Mk.80 series free-fall bombs fitted with a laser guidance kit. LGBs rely on the target being illuminated by a ground-based or air-borne laser designator. Since optical wavelengths are absorbed by water, adverse weather sush as fog, clouds, or rain tend to restrict the employment of laser-guided weapons. Although LGBs offer pinpoint accuracy in clear weather (day or night), they are of limited use in adverse weather.
At the same time, typical mission profiles flown in Desert Storm rendered unguided munitions even less precise. Aircraft would drop bombs from medium or even high altitude to avoid small-arms anti-aircraft fire, which degrades the accuracy of the unguided munitions.
These two factors established the need for a precision guided munition for all weather conditions. In the early 1990s, General McPeak, then USAF Chief of Staff, wrote down on a piece of paper something that he wanted industry to produce for him. He wanted an all weather precision guided bomb - something that didn't depend on good visibility like laser guided bombs. He even wrote down 'radar guided'. He didn't know tech things, he was a pilot by trade, all he knew is that he wanted a problem solved: to hit targets in any weather.
Research and development of the JDAM began in 1992. GPS assisted inertial naviation was selected as guidance technology, mainly due to its low cost and off-the-shelf availability. A strike aircraft could acquire targets with advanced all-weather sensors, such as synthetic aperture radar (SAR), program GPS-assisted weapons to hit individual targets at specific locations, drop the weapons simultaneously, and then leave immediately. The weapons would proceed on track to their individual targets without further intervention.

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USAF F-16C block 42 #88456 from the F-16 CTF at Edwards AFB, dropping a JDAM bomb during a high-altitude test flight. Note the typical JDAM jacket and tail section containing the guidance section. (USAF photo)
===

In October 1995, the Air Force awarded a contract for EMD and for the first 4,635 JDAM kits at an average unit cost of $18,000, less than half the original $40,000 estimate. At the same time, Northrop Grumman had a contract with the USAF to produce the “GAM”.( GPS assisted munition ) kit for 2000lb class dumb iron. The GAM entered testing with the B-2 bomber. Some GAM kits also were to end up on the 4500lb class "bunker buster" GBU-37 for use with the B-2. The Nortrop Grumman GAM was a competitor to the Boeing JDAM. In the end, Boeing JDAM won the contract to provide GPS assisted kits to the USAF and Navy. The first JDAMs were delivered in 1997 with operational testing conducted in 1998 and 1999. More than 450 JDAMs were dropped during testing, recording an unprecedented 95 percent system reliability while achieving a 9.6-meter accuracy rate. JDAM performance has been demonstrated in adverse weather conditions, including drops through clouds, rain and snow.
The US Air Force, Navy, and Marine Corps originally planned to acquire a total of over 87,000 JDAM kits from Boeing, with total program cost of over $2 billion USD. The US military has been so enthusiastic about the weapon that their total buy may reach about 250,000, and there has been talk of eliminating unguided bombs entirely from the inventory. JDAM has also been sold to foreign customers, with Israel and Italy placing the first export orders.

Construction
The JDAM kit is a rather simple modification, which explains its low cost. It consists of a tail section and a jacket which is wrapped around the body of the free-fall bomb. Different tails and jackets are available for different bombs.

===
Graphic not shown
===

Key to drawing:
1. Warhead
2. Suspension lugs
3. 1760 interface
4. Jacket
5. Strakes
6. Guidance section
7. Fins

The tail has moveable fins, and contains a thermal battery and a guidance system. The latter consists of a GPS (Global Positioning System) receiver and an Inertial Navigation System (INS). The guidance system is connected to the parent aircraft by an umbilical connection, though a wireless infrared link is in the works. Different fuses are available: the BLU-109 and BLU-110 penetrator warheads will penetrate the surface before detonating, but the fuse can also be set for airburst or contact.
The jacket is wrapped around the body of the bomb. Its purpose is to enhance maneuverability and range through the mid-body strakes that act as aerodynamic surfaces.

Laser-JDAM

Laser-JDAM is currently in testing. This gives the weapon a “dual-use” role. To hit a target with GPS/INS guidance only or act like a traditional laser-guided bomb kit to include help from the GPS/INS system as needed.

Diamond back kit (currently not fielded by F-16 users)

Known as JDAM-ER for “Extended Range”. A fold out wing attached to the JDAM kit, giving it a standoff range of over 25 miles (some sources claim as much as 40 miles).

Affordable Moving Surface Target Engagement program

The Affordable Moving Surface Target Engagement (AMSTE) program aims to show that a remote ground moving target indicator (GMTI) radar and a synthetic aperture radar (SAR) can feed tracking data on moving targets to smart bombs equipped with relatively low-technology data links. An AMSTE-equiped JDAM test-fired from an F-16 and guided by an E-8C JSTARS struck within three meters of a moving truck. Nothing more was heard of this program after a few tests.

Versions ( F-16 users only )

GBU-31

Two versions are available: the GBU-31(V)1/B is based on the 2,000lb Mk.84 warhead, and the GBU-31(V)3/B is based on the 2,000lb BLU-109 penetrator warhead.

GBU-38

A kit made to fit the 500lb, Mk82 dumb iron..
F-16 Installation

===
Roll-out of the first F-16I 'Sufa' (#253) for Israel at LMTAS' Fort Worth facility on November 14th, 2003. Note the CFTs, dorsal spine, GBU-31 JDAMs, and the numerous bulges and fairings for undisclosed equipment. (LMTAS photo)
===

JDAM can only be launched by F-16s that have a digital INS/GPS system with the proper software upgrades to integrate with the weapons management system. JDAM is or can be carried by the following F-16 models: MLU aircraft, block 30/32, block 40/42, block 50/52, block 52+, and block 60. JDAM capability can be added to older models (block 30/32/40/42) by installing a digital INS/GPS system, and installing the required software upgrades. Newer models already have the digital GPS/INS when they roll off the production line. These models can also use their radar to refine the target coordinates. Based on radar returns from the target, target coordinates are determined and fed back into the JDAM guidance section.

===
(graphic not shown
===

F-16 Loadout

The USAF F-16 fleet only uses the 2000lb GBU-31. Stations 3 and 7 have been wired to carry a single JDAM. Other stations are not fully equiped for the JDAM.

F-16 Loading

Munition specialists assemble the bombs on base. They take a conventional dumb bomb, attach the JDAM kit to it and make sure it is serviceable, then load it on the aircraft.
Coordinates for preplanned, fixed targets are fed into the JDAM. These coordinates are for example determined from high-resolution aerial images. If the targets are not pre-planned (e.g. most targets in Afghanistan and Iraq were not), the aircraft carrying the JDAM shows up in the target area and is assigned a target by a JSTARs aircraft, Forward Air Controller, or another source. If the launch aircraft has radar assist capability (e.g. B-1, B-2, F-18E/F, and the latest F-16s), radar data can be used to refine the target coordinates.
The JDAM automatically begins its initialization process during captive carry when power is applied by the aircraft. The weapon performs Built-in Testing, and aligns its INS with the host aircraft’s system. Targeting data is automatically down loaded to the weapon from the host aircraft. When the host aircraft reaches the release point within the Launch Acceptable Region (LAR), the weapon is released.

===
"An 8th FW "Wolfpack" F-16C (Commander's aircraft) dropping a pair of 2000lb GBU-31 JDAM's. (USAF photo)"
===

Once released, the JDAM falls free of the aircraft and attempts to acquire a GPS signal. To improve the chances of GPS acquisition, JDAMs are usually released from high altitude. It can take as much as 10 seconds or more for acquisition to happen. The bomb's 3-axis INS and GPS guidance systems will take over and guide the bomb to its target regardless of weather. There are two modes of operation: either GPS-assisted guidance, resulting in a 13m CEP (Circular Error Probable), or INS-only guidance, resulting in 30m CEP. INS-only is used when the GPS-signal is unavailable, for example when GPS jammers are used by the enemy. The important fact is that the Guidance Control Unit (GCU) provides accurate guidance in both modes, so even when GPS is unavailable the JDAM is still accurate.
JDAMs can be released from over 10 miles away and from high altitude. This allows the launch aircraft to avoid small Surface-to-Air Missiles (SAMs) or Anti-Aircraft Artillery (AAA or triple A), thus increasing survivability.
A particular concern for JDAM is GPS jamming. However, this is less a of problem than originally anticipated. First of all, the GPS signal now resides on a secure topology - the GPS kit knows if it is getting a certified GPS signal or not. The U.S. Department of Defense has received additional funding to make this process even more secure and to improve the ability of the kit to acquire GPS signals under various jamming scenarios. Secondly, if the JDAM kit does not acquire a GPS signal on the way down, the Inertial Navigation System in the kit will get the weapon near the target with variable accuracy (depending on conditions) and will not be influenced if instructions from the GPS fall outside of a certain range. All this was proven in combat when in Iraq, an enemy GPS jammer was taken out with a JDAM.

Operational Use

JDAM and the B-2 made their combat debuts during Operation Allied Force. The B-2s, flying 30-hour, nonstop, roundtrip flights from Whiteman Air Force Base, Mo., delivered more than 600 JDAMs during Allied Force. The JDAM was officially first used by F-16s during Operation Iraqi Freedom.

Specifications

Primary Function: Offensive interdiction precision-guided weapon
Contractor: LMTAS & Boeing
Length: see table below
Launch Weight: see table below
Diameter: see table below
Range: see table below
Guidance System: GPS/INS

Warhead: see table below
Unit Cost: $18,000

GBU-31(v)1/b

3276 Length (mm)
457 Diameter (mm)
909 Launch Weight (kg)
8 - 24 Range (km)
429.5 Warhead (kg)

GBU-31(V)3/B
---- Length (mm)
---- Diameter (mm)
---- Launch Weight (kg)
8 - 24 Range (km)
---- Warhead (kg)

GBU-38
2210 Length (mm)
273 Diameter (mm)
227.3 Launch Weight (kg)
8-24 8 - 24 Range (km)
87.3 Warhead (kg)

Similar Weapons

Advanced Unitary Penetrator

The Advanced Unitary Penetrator (AUP) is a 2,000 lb. penetrator warhead intended as a successor to the BLU-109 warhead. The AUP is designed to provide increased penetration capability while maintaining the same overall weight, dimensions, and physical interfaces of the BLU-109 warhead, thus ensuring compatibility with the GBU-31 guidance kit. The AUP uses the Hard Target Smart Fuze (HTSF), an electronic fuze which allows control of the detonation point by layer counting, distance or time. The HTSF contains an accelerometer which senses G loads caused by sudden deceleration of the bomb as it penetrates through to the target. This allows the fuze to distinguish between earth, concrete, rock and air.

Small Diameter Bomb (SDB)

Unlike JDAM, the Small Diameter Bomb is not a kit that is attached to a dumb bomb, but a single unit consisting of a small 50lb warhead and GPS/INS guidance section. The SDB is designed to fit in the weapons bay of an F/A-22 and weighs only 250lb in total. It has a penetrator shape which offers the same penetration capability as the 2000lb BLU-109 body. The pinpoint accuracy of this weapon combined with its penetration capability more than compensate for the smaller warhead. Initial tests with the F-16 have already been performed. Unit cost of the SDB is high compared to a JDAM kit. There is also a Diamondback option for the SDB which extends the range significantly.

Enhanced Paveway/Paveway IV

Designed with U.K. inventory of free-fall bombs in mind, which are not compatible with the JDAM kit. Paveway IV is a combined laser guided/GPS kit. It can be used as a LGB, or if the target is covered by weather, as a GPS-guided munition. Unit cost is higher than an LGB kit. Enhanced Paveway was used by the U.K. and USAF F-117s in Iraq. Paveway IV is a further development of the Enhanced PAveway, adding a second-generation anti-jam, anti-spoof GPS with a low-cost inertial measurement unit to the laser seeker.

French AASM GPS kit

A GPS/INS guidance kit for free-fall bombs, developed by Sagem. Currently available for 500lb bombs, but kits for heavier bombs are under development. The kit is compatible with an optional strap-on IR seeker. This kit will likely be deployed with the new Rafale fighters. A common configuration for a Rafale and this weapon would be 3 on each wing with the new triple ejector rack, which can also hold the GBU-12 (500lb LGB).

SPICE

Israeli GPS assisted kit for dumb iron with an IR seeker. The kit completely encloses the bomb. Unit cost unknown.

LONGSHOT

LongShot by Lockheed/Martin, is a low-cost, GPS/INS self-contained wing adaptor kit that provides range extension and autonomous guidance capability to a wide range of existing air-to-surface munitions.
Wireless operation. LongShot does not require MIL-STD-1760 interface Using the UHF radio on the jet to punch in the target to the bomb using a keypad like what is on the Upfront Display.

KAB-500E

GPS/Glonass kit for Russian 500kg iron bomb. Total funding and deployment into the Russian Air Force; unknown.

China (PLAAF)

----- (elp)

Sources
• Boeing JDAM webpage: http://www.boeing.com/defense-space/mis ... flash.html
• USAF Fact Sheet "Joint Direct Attack Munitions GBU-31/32": http://www.aog-usafa.org/Fact_Sheets/Jo ... _31_32.htm
• GlobalSecurity.org on JDAM: http://www.globalsecurity.org/military/ ... s/jdam.htm
• Boeing Anti-Jam Press release: http://www.boeing.com/news/releases/199 ... 80423n.htm
• Boeing completes 500lb JDAM testing with F-16. Oct 2002: http://www.boeing.com/news/releases/200 ... 1031m.html
• Boeing demonstrates Diamondback: http://www.afrlhorizons.com/Briefs/Jun02/MN0206.html
• Original thoughts in the UK Parliament on the direction their all weather bomb kit should take: http://www.parliament.the-stationery-of ... 63ap04.htm
• PDF file on Russian GPS/Glonass kit: http://www.milparade.com/2002/54/042.pdf
• Israeli SPICE kit, captive carry on a Saab Gripen: http://www.gripen.com/images/nato/hi_res/1a_hi.jpg

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Enthusiast Joined: May 31, 2005 Posts: 69 Status: Offline

elp, lotta good stuff in here.

You may want to note that JDAM also requires a 1760/1553-capable pylon.

LMTAS no longer exists. LM Aero is the entity that builds F-16s nowadays; it and other divisions of Lockheed Martin huddle under the LMCO banner.

The 2nd paragraph under F-16 Loading is a bit misleading. The first sentence seems to say that the munitions guys load targeting info into the weapon. Only a designation by the pilot will send targeting info to the weapon. The last sentence in that paragraph also implies that the weapon is released automatically once it is within LAR -- it still takes a pilot on the pickle button to drop the weapon (but the pickle button won't be hot until the A/C is within LAR).

You took some pains to exclude GBU-32 since USAF doesn't deploy it, yet you throw out comments about laser JDAM, wireless IR interfaces, etc. as if they're a done deal. You may want to collect those under a "Future Features" caveat to keep Rumor Control satisfied.

You should consider including GBU-38 in your Loadout section. While it's technically true that USAF isn't fielding them yet, they've already been dropped in anger from ANG jets in Iraq. USAF isn't that far behind, both parent carriage and BRU-57.

Good work on collecting all this info -- it's a valuable resource.

F-16.net Editor Joined: Sep 23, 2003 Posts: 2848

Loomis wrote:

elp, lotta good stuff in here.

You may want to note that JDAM also requires a 1760/1553-capable pylon.

LMTAS no longer exists. LM Aero is the entity that builds F-16s nowadays; it and other divisions of Lockheed Martin huddle under the LMCO banner.

The 2nd paragraph under F-16 Loading is a bit misleading. The first sentence seems to say that the munitions guys load targeting info into the weapon. Only a designation by the pilot will send targeting info to the weapon. The last sentence in that paragraph also implies that the weapon is released automatically once it is within LAR -- it still takes a pilot on the pickle button to drop the weapon (but the pickle button won't be hot until the A/C is within LAR).

You took some pains to exclude GBU-32 since USAF doesn't deploy it, yet you throw out comments about laser JDAM, wireless IR interfaces, etc. as if they're a done deal. You may want to collect those under a "Future Features" caveat to keep Rumor Control satisfied.

You should consider including GBU-38 in your Loadout section. While it's technically true that USAF isn't fielding them yet, they've already been dropped in anger from ANG jets in Iraq. USAF isn't that far behind, both parent carriage and BRU-57.

Good work on collecting all this info -- it's a valuable resource.

I thought I did include GBU-38 up there..... Surprised

I excluded GBU-32. Have any F-16s used GBU-32 in the field? Smile

JDAMs fielded by F-16 include??????:

GBU-31 series ( excluding the USN types of course )
GBU-38

Thanks for the input !!

Enthusiast Joined: May 31, 2005 Posts: 69 Status: Offline

I've heard rumors that some enterprising units borrowed GBU-32s from their Navy cousins during OEF, but I've never seen that confirmed. The capability for deploying GBU-32 has been included and tested in every USAF F-16 OFP since 50T5, so there aren't any technical obstructions to their use.

F-16.net Editor Joined: Sep 23, 2003 Posts: 2848

Well we can always add it to the list later if it becomes more obvious that some units use it on a regualar basis. So based on that...

List GBU-32 now or just add it at a later date?

Enthusiast Joined: May 31, 2005 Posts: 69 Status: Offline

I'd say add it later.

elp:

Quote:

Also in the similar weapons section, I need to add the new Chinese GPS assisted dumb iron kit. Anyone with the nomenclature on that??

The Chinese doofer is called LS-6 and it weighs 1000lb

F-16.net Editor Joined: Sep 23, 2003 Posts: 2848

RoAF wrote:

elp:

Quote:

Also in the similar weapons section, I need to add the new Chinese GPS assisted dumb iron kit. Anyone with the nomenclature on that??

The Chinese doofer is called LS-6 and it weighs 1000lb

Thanks RoAF !!!!!! Smile

is the SDB (small diametre bomb) a gbu37/38/39...
at this link on my blog: http://bugietotali.blogspot.com/2007/09 ... zione.html
I write it is not a GBU 28, but a GBU SDB 37-38 or 39?

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