The weapon, also known as Small Diameter Bomb II, is currently being integrated on the F-35 as part of the Block 4 upgrades.
Italy is acquiring the GBU-53/B StormBreaker, also known as Small Diameter Bomb Increment II, to equip its F-35s once they are upgraded to the new Block 4 configuration. The info, previously undisclosed, was contained in the Air Force Life Cycle Management Center’s contract award for the Production Lot 10 of the weapon.
In fact, the U.S. Department of Defense published the contract notice on Dec.29, 2023, mentioning that this lot is destined to Foreign Military Sales to Norway, Germany, Italy and Finland. Here is the full notice:
Raytheon, Tucson, Arizona, has been awarded a $344,619,301 modification (P00004) to previously awarded contract FA8681-23-C-B001 for StormBreaker® (SDBII, GBU-53/B) Production Lot 10, for additional all up rounds, containers and trainers. Work will be performed in Tucson, Arizona, and is expected to be completed by Aug. 30, 2028. This contract involves Foreign Military Sales (FMS) to Norway, Germany, Italy and Finland. Fiscal 2023 Air Force procurement missile funding in the amount of $101,394,424; fiscal 2024 Air Force procurement missile funding in the amount of $183,097,105; fiscal 2024 Navy procurement weapons funding in the amount of $58,009,800; and FMS funding in the amount of $2,117,972 are being obligated at the time of award. The Air Force Life Cycle Management Center, Eglin Air Force Base, Florida, is the contracting activity.
While the acquisition of the GBU-53 by Norway, Germany and Finland via FMS was already known, this is the first time Italy is mentioned among the countries receiving the weapon. In fact, no info about the FMS to Italy can be found on the Defense Security Cooperation Agency (DSCA). However, documents from the Italian Parliament explicitly mention the GBU-53/B among the modernization and renovation program, with the first funds allocated in the 2019 budget law.
Raytheon, now RTX, describes the GBU-53/B as a network enabled weapon, saying this is one of the key benefits of StormBreaker. This capability is intended to give an aircraft the possibility to drop the weapon and then hand off its controls to another aircraft connected to the same network. This is considered critical for a JADC2 (Joint All Domain Command and Control) battlespace environment as the military aims to connect sensors, platforms and weapon systems for multi-domain operations.
More from The Aviationist
The F-35 will be able to carry eight StormBreaker weapons internally and eight externally, providing the 5th gen aircraft with the capability to hit moving targets in adverse weather, addressing a wide range of threats and scenarios. Further versatility is added by the multi-effects warhead, which is equipped with shaped charge jets, fragmentation and blast charge effects, and an option for a delayed smart fuze. The total weight of the weapon is just over 200 pounds, with half of it being the warhead alone.
Another key feature of the GBU-53/B is its tri-mode seeker that employs imaging infrared and millimeter wave radar to see through fog, smoke and rain as the weapon glides over 45 miles to strike both fixed or moving targets on land or at sea. The other modes available for target acquisition are the more common semi-active laser homing and GPS/INS guidance.
