A KC-135 Stratotanker from the 465th Air Refueling Squadron assigned to Tinker Air Force Base, Oklahoma, refuels a B-52 Stratofortress from the 96th Bomb Squadron assigned to Barksdale Air Force Base, Louisiana, during a cross country mission Sept 13, 2021. (U.S. Air Force photo by 2nd Lt. Mary Begy)
WASHINGTON — The Rolls-Royce F130 engine is one step closer to powering the US Air Force’s B-52 Stratofortress fleet following a successful critical design review (CDR), the company told Breaking Defense.
Held in October but not publicly revealed until now, the F130 CDR marks a key milestone in the engineering process that validates the maturity of a design.
The company will still have to address some extra steps to fully close out the CDR — those should be taken within the next few months, a spokesperson said — but it can now turn its attention to additional testing and prepare for production efforts. Eventually, Rolls-Royce is expected to install the F130 across the Stratofortress fleet and replace the current Pratt & Whitney TF33, in line with the $2.6 billion contract Rolls-Royce won in 2021 and as the central piece in the wider B-52 Commercial Engine Replacement Program (CERP).
The CDR had been expected as far back as January, but the spokesperson said the October review was still within the Air Force’s schedule.
“A combination of integration improvements and the desire to fully analyze results” from twin pod tests Rolls-Royce ran at NASA’s Stennis Space Center “drove the timing,” the spokesperson said.
B-52-maker Boeing leads the overall CERP effort as the prime integrator, which involves other changes to the decades-old bomber like upgraded avionics.
The CERP aims to offer greater fuel efficiency and maintainability improvements, recasting the B-52H as the B-52J after the overall project is completed. It’s a big revamp for the Air Force’s fleet of 76 Eisenhower-era bombers, which each carry four twin pods for a total of eight engines each and will be expected to fly with the new F130s until the end of their service lives well into the 2050s, if not longer.
A parallel effort, the B-52 Radar Modernization Program, will integrate a new RTX-made radar.
Boeing will lead a separate CDR for the overall CERP effort, which the Government Accountability Office found earlier this year is planned for August 2025 [PDF], roughly two years behind schedule. The same report found that the program’s initial operational capability (IOC) may be delayed by as long as roughly three years, out to 2033.
Air Force officials earlier this year told reporters they were working through ways to hold down costs and claw back lost time for the two B-52 upgrade programs, including by bringing on Shay Assad, the Pentagon’s former longtime director of defense pricing notorious for tough negotiations with industry.
“We are working very closely with our partners at Boeing and the Air Force to support the program, address any issues, and assist in any way we can,” the Rolls-Royce spokesperson said. Boeing referred comment for this report to the Air Force. A spokesperson for the service confirmed that the CERP’s system-level CDR is planned for “late summer 2025,” and that IOC is planned for fiscal year 2033. A formal cost baseline for CERP will be established at the program’s Milestone B decision, set for “summer 2025,” the spokesperson added.
Rolls-Royce officials are now underway with new engine trials at the company’s Indianapolis, Ind., facilities after wrapping up crosswind testing, as a production decision inches closer.
“The F130 First Engine to Test (FETT) started sea-level testing in Indianapolis this fall, which included running the engine’s initial software release,” the spokesperson said. “The FETT sets the performance baseline for the F130, supported by the over 30 million engine flying hours” from the company’s commercial family of engines the F130 is based on.
Looking ahead, the engine will also undergo altitude testing at the Air Force’s Arnold Engineering Development Complex in Tullahoma, Tenn. The company will also conduct “durability testing” in Indianapolis ahead of initial flight release, the spokesperson said.
The CERP contract awarded to Rolls-Royce calls for 608 engines, as well as spares. By the early 2030s, the company “expect[s] to increase production of our combat portfolio to over 100 engines per year,” according to the spokesperson.
“To date, our testing program confirmed our predictions and is allowing us to stay on track to deliver this fixed price contract for the Air Force,” the spokesperson said.
