The U.S. Air Force reached two acquisition milestones in 2026 for the long-term modernization of the B-52 Stratofortress fleet. Milestone B approval came on June 1 for the B-52J Commercial Engine Replacement Program, which moves the engine upgrade into development. Milestone C approval followed on Aug. 21 for the B-52 Radar Modernization Program, which authorizes radar upgrades to begin production. The Air Force says the work keeps the bomber operationally relevant through 2050 and beyond.
The engine program replaces the original TF33 engines with commercial-derivative Rolls-Royce F130 engines. It also modernizes supporting subsystems, including hydraulic pumps, cockpit displays, flight systems and generators that raise electrical power capacity. The Milestone B decision set the program's first official Acquisition Program Baseline at a total acquisition cost of $20.2 billion, of which $2.6 billion has been spent since 2018. Engineers redesigned the nacelle and inlet after early wind-tunnel testing found inlet airflow distortion, and the critical design review with Boeing and Rolls-Royce finished in May 2026. Engine testing continues.
The radar program replaces the 1980s-era APQ-166 analog radar with the APQ-188 active electronically scanned array radar. On Aug. 21 the program awarded low-rate initial production contracts to Raytheon for the radars and to Boeing for aircraft integration kits, starting with Lot 1 of four kits. The five-lot production plan will deliver 74 kits in total.
Two test aircraft that are flying operational missions after recent depot maintenance are scheduled to enter modification at Boeing's San Antonio facility in the coming months. Both sets of changes will be installed on those jets at the same time. Structural assessments done for the engine program found that the airframes, built from the late 1940s into the early 1960s, have enough fatigue life to operate well into the 2050s.
Source: Aerotech News & Review - https://www.aerotechnews.com/blog/2026/10/05/b-52-achieves-key-milestones-for-engine-radar-modernization/