|GBU-53/B (Small Diameter Bomb II)|
|Place of origin||United States|
|In service||2017– (planned)|
|Used by||United States|
|Unit cost||US$129,441 (FY13)
US$224,906 (inc R&D)
|Number built||17,143 planned|
|Weight||204 lb (93 kg)|
|Length||69 in (176 cm)|
|Diameter||6-7 in (15-18 cm)|
|Warhead||105 lb (48 kg)|
|45 miles (72 km) against moving targets|
|Millimeter wave Active radar homing / Semi-active laser guidance / Infrared homing (using an uncooled imaging infrared camera) / GPS coupled Inertial guidance / Data Link|
The GBU-53/B Small Diameter Bomb II is an American air-launched, guided bomb.
Development was started in 2006 for a 250 pounds (113 kg) class bomb that can identify and strike mobile targets from standoff distances in all weather conditions. It will be integrated on the F-15E and F-35 Joint Strike Fighter. Its first flight was announced on May 1, 2009.
The bomb is being developed by Raytheon. A Boeing/Lockheed Martin team attempted to develop it but lost in a U.S. Air Force competition. Boeing won the original competition but the project was on hold for several years due to a corruption scandal involving Darleen Druyun. The competition was reopened in September 2005.
The bomb uses GPS/INS system to guide itself into the general vicinity of a moving target during the initial search phase, with any necessary course correction updates provided using a Link 16 or UHF data link. The bomb has three modes of target acquisition: millimeter-wave radar, Infrared homing based on uncooled imaging infrared, and semi-active laser. The weapon is capable of fusing the information from the sensors to classify the target and can prioritize certain types of targets as desired when used in semi-autonomous mode.
The shaped charge warhead in the bomb has both blast and fragmentation effects, which makes it effective against infantry, armor (including MBTs), unhardened structures and buildings, as well as patrol craft sized boats and other soft targets. The bomb would be the first purpose-built no-drive zone enforcement weapon.
The use of uncooled imaging infrared has been cited as innovative and effective in reducing costs. An important feature of the new weapon is the maximization of the number of the bombs carried by the strike aircraft. A total of 28 GBU-53/B can be carried by the F-15E Strike Eagle utilizing 7 BRU-61/A suspension units, each carrying 4 bombs, and eight bombs along with two AIM-120 AMRAAM missiles in the weapons bay of the F-22 Raptor or the F-35 Lightning II (even the STOVL F-35B). However, the F-35 will not be able to operate the bomb until it receives the Block 4A software package in 2022. The SDB II bomb rack was found to not fit inside the smaller F-35B weapons bay, although modifications to fix this will be put off to coincide with the software package so it will be able to deploy the weapon once remedied.
The bomb is being tested using F-15E aircraft and a UH-1 helicopter.
Raytheon is offering the SDB II to the United Kingdom for their Spear Capability 3 requirement to arm the Royal Air Force Eurofighter Typhoon and Royal Navy F-35B. Deliveries could potentially begin by 2017. Raytheon is competing against the MBDA for supplying a weapon for the Spear Capability 3 requirement.
The original Small Diameter Bomb (SDB) was developed by Boeing and made for non-moving targets. The SDB II is designed to destroy moving targets in dust and bad weather. The Raytheon version was deployed successfully in 26 missions over 21 days. Raytheon was awarded the contract in August, 2010. The North American division of MBDA continues to produce the wings. The Raytheon contract is worth US$450 million. Boeing announced that it would not protest the Raytheon award.
On July 17, 2012, the SDB II successfully engaged and hit a moving target during a flight test at the White Sands Missile Range. The bomb was dropped from an F-15E Strike Eagle, then acquired, tracked, and guided itself onto a moving target using its tri-mode seeker, scoring a direct hit.
In January 2013, four SDB IIs were loaded into the weapons bay of an F-35 Lightning II alongside an AIM-120 AMRAAM missile. The successful fit check validated that the SDB II was compatible with the F-35 and gave adequate clearance in sweeps of inboard and outboard bay doors.
Two SDB IIs successfully conducted live fire tests against moving targets, one in September 2014 and the other in February 2015. Successful live fire tests qualifies the weapon for the Air Force to make a Milestone C decision, leading to entering low-rate initial production (LRIP), likely to occur in summer 2015.
The United States Air Force plans to use the bomb on the F-15E Strike Eagles as a no-drive zone enforcement weapon. The U.S. Navy and U.S. Marines plan to use it on their versions of the F-35 Joint Strike Fighter. Delivery for the first batch is planned for late 2014. Government requirements specify a 2016 delivery date.
- "GAO-13-294SP DEFENSE ACQUISITIONS Assessments of Selected Weapon Programs". US Government Accountability Office. March 2013. pp. 101–2. Retrieved 26 May 2013.
- Small Diameter Bomb II Completes Live Fire Test Destroying T-72 Tank - Military.com, 25 February 2015
- "Air Force picks small diameter bomb". United Press International.
- "Raytheon GBU-53/B Small Diameter Bomb II Completes First Flight". Space.
- "Raytheon Wins USAs GBU-53 Small Diameter Bomb Competition". http://www.defenseindustrydaily.com/ Defense Industry Daily.
- "Small Diameter Bomb II - GBU-53/B". Defense Update.
- F-35 Will Not Reach Full Close-Air-Support Potential Until 2022 - DoDBuzz.com, 10 March 2015
- Raytheon takes aim at UK Spear deal with SDB II - Flightglobal.com, 23 July 2014
- "Raytheon wins USA GBU-53/B small diameter bomb competition". Defense Industry Daily.
- MBDA US Division Corporate
- Small Diameter Bomb II Successfully Hits Moving Target on the Ground - Deagel.com, July 19, 2012
- Small Diameter Bomb II Fit Check on F-35 Aircraft - Airforce-Technology.com, January 23, 2013
- SDB II undergoes live fire testing on F-15E - Flightglobal.com, 19 February 2015