USA Weapons
GBU-1/B, GBU-2/B, GBU-3/B, GBU-5/B, GBU-6/B, GBU-7/B, GBU-10/B, GBU-11/B, GBU-12/B
History and General Description
In 1965, the USAF's Armament Development and Test Center at Eglin AFB began the evaluation of laser guidance systems for free-fall bombs. Such systems generally consist of a laser illuminator, which marks the target with a laser beam (typically with a near-infrared wavelength), and a seeker, which detects the laser's reflection and guides a weapon towards it. In April 1965, the first successful drop of an LGB (Laser-Guided Bomb) using a guidance system from Texas Instruments (TI) occurred. The Air Force subsequently began the Paveway (originally Pave Way) program for full-scale LGB development, and TI received a contract to produce KMU-342/B laser guidance add-on kits for the 750 lb class M117 general purpose bomb. M117s with a KMU-342/B kit were known as "BOLT-117" (BOLT = Bomb, Laser, Terminal Guidance), and were first used operationally over Vietnam in 1968.
Laser guidance not only improved the accuracy of the bombs by about 100 times, but the added stand-off range also often allowed the bombers to stay outside air defense range. After the initial success, Paveway laser guidance kits were designed and produced for a variety of bombs, including the widely used 2000 lb MK 84 and 500 lb MK 82 bombs and several types of cluster munitions (see Variants section below for a detailed rundown of all versions). The original Paveway system was renamed Paveway I after the Paveway II follow-on program had been started in 1972.
A Paveway I add-on kit consisted of a gimballed seeker head, a Computer Control Group (CCG), and a set of airfoils. The latter were made up of fixed cruciform tailfins (also referred to as wings) and four movable canards (except for the KMU-342/B, which had the moving surfaces on the tail). The airfoils of the GBU-2/B, GBU-10/B (MXU-600( )/B) and GBU-12/B (MXU-602( )/B) came in two different versions, with "short wings" and "long wings". The latter had wing extensions for slower delivery speed but higher stand-off range (the extensions could optionally be removed before the mission). The LGB's seeker head was fitted with a ring airfoil which kept it aligned with the bomb's flight path. The CCG had a relatively simple "bang-bang" autopilot, i.e. the control surfaces were either deflected fully or not at all, resulting in a sub-optimal flight path (this drawback was not addressed before the introduction of the Paveway III LLLGB (Low-Level LGB) system). The big advantage of the Paveway concept is that virtually no modifications on the delivery aircraft are necessary. The laser designators, e.g. the early AN/AVQ-10 PAVE KNIFE, or the later AN/AVQ-23 PAVE SPIKE and AN/AVQ-26 PAVE TACK, can be carried either by the delivery aircraft itself or by other aircraft in the strike group. There are also portable laser designators for ground troops.
More than ten thousand Paveway I LGBs were used with great success by the U.S. Air Force over South East Asia. The U.S. Navy hesitated longer to adopt LGBs on a large scale, and dropped only a few hundred Paveway I bombs in that conflict. The reason for this reluctance is the fact that when a sortie is cancelled after the aircraft are already in the air, bombs are normally jettisoned over water for safety reasons before returning to the aircraft carrier. Throwing away relatively expensive electronic guidance kits was considered undesirable. The Navy didn't take full advantage of LGB technology until the introduction of the cheaper Paveway II system. In U.S. military service, all Paveway I guidance kits have been retired in favour of the Paveway II, but residual Paveway I kits have been used for training for some time.
Variants
Early Paveway and Pave Storm versions
The first Paveway LGBs were usually referenced by the KMU-xxx/B designations of the guidance kits, and not by GBU numbers. In some cases it is not even clear if GBU designations for the all-up rounds were ever assigned. The name Pave Storm was sometimes used for cluster bombs with Paveway guidance, especially for the GBU-2/B. The following weapons could be fitted with Paveway I guidance kits:
" M117: 750 lb class general purpose bomb
" M118E1: 3000 lb class demolition bomb (see GBU-11/B section below)
" MK 82: 500 lb class LDGP (Low-Drag General Purpose) bomb (see GBU-12/B section below)
" MK 83: 1000 lb class LDGP (Low-Drag General Purpose) bomb
" MK 84: 2000 lb class LDGP (Low-Drag General Purpose) bomb (see GBU-10/B section below)
" MK 20 "Rockeye": 500 lb cluster bomb, consisting of a MK 7 MOD 2 dispenser filled with 247 MK 118 0.9 kg (2 lb) anti-tank bomblets
" CBU-74/B: Cluster bomb, consisting of a SUU-51/B dispenser filled with 48 BLU-87/B 6.1 kg (13.4 lb) anti-personnel fragmentation bomblets
" CBU-75/B: 2000 lb cluster bomb, consisting of a SUU-54A/B dispenser filled with 1800 BLU-63/B 0.45 kg (1 lb) APAM (Anti-Personnel/Anti-Materiel) fragmentation bomblets
" CBU-79/B: Cluster bomb of the "Gator" family, using 2 kg (4.3 lb) BLU-91/B anti-tank and 1.7 kg (3.7 lb) BLU-92/B anti-personnel mines
" CBU-80/B: Cluster bomb (details not available)
Specifications
Data given by several sources show slight variations.
|
GBU-2A/B |
GBU-10/B |
GBU-11/B |
GBU-12A/B |
Length |
4.57 m (15 ft) |
4.32 m (14 ft 2 in) |
4.19 m (13 ft 9 in) |
3.20 m (10 ft 6 in) |
Diameter |
51 cm (20 in) |
46 cm (18 in) |
63.5 cm (25 in) |
27.3 cm (10.75 in) |
Fin span |
1.37 m (4 ft 6 in) |
1.14 m (3 ft 9 in) |
1.22 m (4 ft) |
0.99 m (3 ft 3 in) |
Weight |
1000 kg (2200 lb) |
943 kg (2080 lb) |
1391 kg (3066 lb) |
295 kg (650 lb) |
Warhead |
CBU-75/B cluster bomb |
MK 84 bomb |
M118E1 bomb |
MK 82 bomb |
GBU-10/B, GBU-12/B, GBU-16/B, GBU-17/B, GBU-48/B, GBU-49/B, GBU-50/B, GBU-51/B
History and General Description
The Paveway I laser-guided bombs had been used by the USAF very successfully in the later phases of the Vietnam war. The Paveway II follow-on development rectified two major shortcomings of the first version: the Computer Control Group (CCG) was significantly simpler and therefore cheaper, and the fixed tailfins were replaced by foldable ones. The latter feature combined the advantages of both the "long wing" and "short wing" versions of the Paveway I airfoil groups - high speed delivery and long stand-off range. It also allowed for easier ground handling and more compact storage and carriage. Prototype testing of Paveway II guidance kits started in 1974, and production began in 1977.
Paveway II guidance kits were produced for the 2000 lb class MK 84 and BLU-109/B, the 1000 lb MK 83 and the 500 lb MK 82 bombs (see Variants section below for a detailed rundown of all versions). Including foreign sales, more than 100000 Paveway II kits have been built, and production and upgrades are still continuing. The primary manufacturer for Paveway II is Raytheon, building the MAU-169( )/B series of CCGs. In the early 2000s, Lockheed Martin established itself as a second source, and currently produces the MAU-209( )/B CCG, which is interchangeable with the MAU-169( )/B. The current version of the MAU-209 is the MAU-209B/B, which has completely replaced the original MAU-209/B.
In good conditions, a Paveway II LGB has an accuracy of about 6 m (20 ft) CEP. However, laser guidance doesn't work very well in bad weather, and when the illuminating laser is switched off for any reason, guidance is completely lost. To overcome these shortcomings, a GPS-aided inertial add-on package for Paveway II LGBs was developed (as was done for Paveway III). GPS/INS-enabled LGBs are frequently referred to as EGBUs (E = Enhanced). So far, Raytheon-built Paveway II EGBUs have primarily been produced for export, and have already been used in combat by the British Royal Air Force over Afghanistan and Iraq.
Lockheed Martin has developed its DMLGB (Dual-Mode LGB) GPS/INS upgrade for Paveway II, and in November 2005, the company received a U.S. Navy contract for further development and eventual production of DMLGB kits to upgrade the Navy's Paveway II stockpile. Primary focus is on the 500 lb GBU-12/B series, but the 1000 lb GBU-16/B and 2000 lb GBU-10/B are planned to follow.
Variants
GBU-10/B, GBU-50/B
The GBU-10/B series covers Paveway I and Paveway II LGBs with warheads in the 2000 lb class. The following warheads are used in GBU-10/B series LGBs:
" MK 84: Standard 2000 lb LDGP (Low-Drag General Purpose) bomb
" BLU-109/B: 2000 lb class penetrator warhead
" BLU-117/B: In place of the MK 84, the U.S. Navy also uses the BLU-117/B warhead. The BLU-117/B is externally identical to the MK 84, but uses the PBXN-109 thermally insensitive explosive and has external protective coating.
The designation GBU-50/B covers Raytheon Enhanced Paveway II GPS/INS-equipped GBU-10/B variants, which are informally also known as EGBU-10.
GBU-17/B
The GBU-17/B was to be a HSM (Hard Structure Munition) penetrator warhead with a Paveway II guidance kit, but this version was not built.
GBU-51/B
The GBU-51/B is a 500 lb class Paveway II laser guided bomb, which uses the BLU-126/B LCDB (Low Collateral Damage Bomb) warhead. The BLU-126/B is externally identical to the BLU-111( )/B, but is filled with less explosives for a reduced fragmentation pattern blast radius. The LCDB was developed by the U.S. Navy for use in situations where friendly forces and/or civilians are close to the target.
Inert Paveway II LGBs
The LGTR (Laser Guided Training Round) is an inert cylindrical bomb body of 10 cm (4 in) diameter with a Paveway II guidance kit, and emulates the GBU-10( )/B, GBU-12( )/B and GBU-16( )/B live munitions. It is used by the U.S. Navy for operational Paveway II training to preserve the stockpile of live bombs and their guidance kits.
The LGTR comes in several versions, including the BDU-57/B, BDU-59/B, BDU-59A/B, BDU-59B/B, BDU-60/B and BDU-60A/B (the BDU-60( )/B series is usually referred to as LGTR II). Since 1992, Lockheed Martin has delivered more than 50000 LGTRs to the U.S. Navy, and production is continuing.
Specifications
Data for GBU-10E/B, GBU-10J/B, GBU-12B/B, GBU-16/B, LGTR:
|
GBU-10E/B |
GBU-10J/B |
GBU-12B/B |
GBU-16/B |
LGTR |
Length |
4.32 m (14 ft 2 in) |
4.24 m (13 ft 11 in) |
3.33 m (10 ft 11 in) |
3.68 m (12 ft 1 in) |
1.90 m (6 ft 3 in) |
Diameter |
46 cm (18 in) |
37 cm (14.5 in) |
27.3 cm (10.75 in) |
35.6 cm (14 in) |
10 cm (4 in) |
Fin span |
1.68 m (5 ft 6 in) |
1.34 m (4 ft 4.75 in) |
1.60 m (5 ft 3 in) |
? |
|
Weight |
957 kg (2110 lb) |
966 kg (2130 lb) |
275 kg (606 lb) |
495 kg (1092 lb) |
40 kg (89 lb) |
Warhead |
MK 84 bomb |
BLU-109/B |
MK 82 bomb |
MK 83 bomb |
none |