Small Diameter Bomb

Small Diameter Bomb (SDB) is an Air Force tactical-missile procurement line under appropriation 3020F, Missile Procurement, Air Force; Budget Activity 02, Other Missiles; and Budget Sub Activity 2, Tactical. Its principal weapon, the GBU-39/B SDB Increment I, is an air-launched precision munition intended to increase kills per sortie while allowing aircraft to carry multiple weapons. It supports attacks on fixed and stationary targets in adverse weather, standoff employment, and close air support. Its small footprint and precision are intended to improve effectiveness while limiting collateral damage and susceptibility to countermeasures.

GBU-39/B SDB Increment I was developed as an Air Force Acquisition Category II program, with the F-15E as its threshold aircraft. It completed initial operational test and evaluation in June 2006 and entered full-rate production in December 2006. Integrated aircraft now include the F-15E, F-22A, F-16C/D Block 30/40/50, F-35A, and AC-130W/J. The broader objective-platform list also includes the B-1, A-10, B-52, B-21, and MQ-9.

GBU-39A/B Focused Lethality Munition (FLM) is a low-collateral-damage SDB I variant. Its carbon-fiber warhead case disintegrates when the fill detonates, reducing fragmentation effects on people and property. GBU-39B/B Laser SDB adds a laser seeker for self-targeting while retaining a GPS-only mode. This 250-pound-class weapon uses deployable wings for standoff range and a height-of-burst fuze for selectable effects.

GBU-39E/B is a 250-pound, GPS-aided precision glide weapon that uses M-Code for precise positioning services. It is designed for autonomous air-to-ground employment by day or night and in adverse weather. The planned addition of M-Code capability to the FY 2027 lot is the stated reason for a substantial increase in end-item unit cost over FY 2026. The Air Force identifies the corresponding improvement in warfighter capability as the justification for that higher price.

BRU-61 Bomb Rack Unit is the four-place carriage and release system for GBU-39 weapons. Its pneumatic ejector and MIL-STD-1760 and JMMI interfaces connect it with the aircraft and attached weapons, respectively. The BRU-61/A converts 115-volt alternating-current aircraft power to 28-volt direct current; the BRU-61B/A accepts either 115-volt alternating current or 270-volt direct current and supplies 28 or 32 volts. Weapons and their containers are procured together, as are racks and their containers, although individual containers may be purchased when needed.

FY 2027 funding requests 220 SDB Increment I weapons, BRU-61 equipment, Operational Flight Program (OFP) updates and testing, and integration supporting the OFP. It also provides for obsolescence work, contractor program-support services, and government operating costs such as travel and Government Purchase Card purchases. Procurement sustains current combat operations and replenishes weapons and variants expended in them. Inventory objectives can change during execution as combatant commanders update operational-plan requirements or critical shortfalls emerge.

Production-sustainment funding can address diminishing manufacturing sources, material shortages, and obsolete parts through studies, bridge or life-of-type buys, replacement suppliers or components, and ground or flight qualification. The program also uses common-component development with other weapon systems and invests in digital, data, network, facility, and security infrastructure directly supporting its capabilities. These efforts include integration of qualified M-Code-capable GPS receivers and may resolve identified performance deficiencies. Contractor support includes Engineering, Professional, and Administrative Support Services.

Boeing in St. Louis is the listed manufacturer for the FY 2027 lot, with an award planned for March 2027 and first delivery in March 2028. The follow-on indefinite-delivery/indefinite-quantity solicitation was issued in August 2022 for a ten-year ordering period: five years with pricing and five to be priced later. Air Force quantities are to be combined with expected Foreign Military Sales purchases to meet minimum-order requirements; the planned Air Force-only FY 2027 quantity is below the manufacturer's minimum sustained rate. The production schedule pairs it with foreign-sales deliveries, while final quantities may change with negotiated pricing, available funding, and inventory needs.