The Air Force expects to complete qualification testing of the brand new engines planned for the B-52 Stratofortress by the top of 2024.
And the service plans to make a Milestone B decision on the Industrial Engine Alternative Program by the top of the summer, which might allow it to maneuver into its engineering and manufacturing development phase, officials said in an interview with Defense News.
These developments will mark critical milestones within the Air Force’s effort to upgrade its fleet of 76 Cold War-era B-52s with recent engines, radar, avionics, and other improvements to maintain it flying until perhaps 2060, a few century after the B-52H was first introduced. The planes’ Sixties-era TF33 engines are at the top of their working lives, and are to get replaced by Rolls-Royce’s F130 engine.
Col. Scott Foreman, B-52 system program manager who oversees the bomber’s sustainment and modernization efforts at Tinker Air Force Base in Oklahoma, and CERP program manager Lt. Col. Tim Cleaver said within the interview that the bottom can also be taking several steps to arrange for the numerous modernization work.
This includes plans to construct an enormous hangar at Tinker starting in 2026, which could house as much as 4 B-52s and increase the quantity of labor that may be done on the bomber at any given time.
The Air Force desires to “get these H models converted to [B-52]J models as quickly as possible, because … the clock’s ticking on those TF33″ engines, Cleaver said.
The Air Force knows the F130 engine works, Cleaver said, since a version of it has powered the Gulfstream G650 business jet for years. However the F130s can be mounted otherwise on the B-52, and the Air Force must be sure there aren’t any surprises with the bomber’s twin-pod, under-wing configuration.
Rolls-Royce last 12 months accomplished much of the initial twin-pod testing of the F130 engines at NASA’s Stennis Space Center in Mississippi, Cleaver said, and the last six-week test cycle there is anticipated to begin in early March. Those tests will involve exposing the engine pods to cross-wind blowers, and seeing what happens if one engine within the pod has to operate at reduced power or is even inoperative.
More tests will follow, Foreman said. In April, the F130 will start sea-level performance testing on a stand at a Rolls-Royce facility in Indianapolis. One other engine will undergo durability testing through 2025, Cleaver said. And this fall, F130 testing will move to the Arnold Engineering Development Complex in Tennessee, where it can be subjected to simulated altitudes to supply more data on how it’d behave in flight.
Once that round is completed, they said, the F130 may have finished its qualification testing that ensures it might be secure to fly, and pave the best way for test modifications to start.
The primary two test B-52s can be modified at Boeing’s San Antonio, Texas facility starting in 2026. It’ll take just a few years to upgrade these bombers for the primary time, Cleaver said, and ground and flight tests will go from late 2028 to 2031.
After this 12 months’s testing, Boeing will arrange 4 systems integration laboratories to make sure adding the brand new engines onto the B-52 will go easily, Cleaver said. Three can be in Oklahoma City, near Tinker Air Force Base, and the fourth — specializing in the engines’ electrical systems — can be at a Boeing facility near Seattle.
“We’ve got a mixture of simulated functions and hardware … functions to be sure that our systems are working with one another, and that we’re not using the test aircraft as our place to search out problems,” Cleaver said. The labs “will really prove out the design before we even cut right into a jet.”
The Air Force continues to be awaiting cost estimate updates from Boeing — which originally built the Stratofortress and is the prime integrator on the upgrade program — before it will possibly finalize its own cost expectations and make a Milestone B decision, Cleaver said. Boeing is anticipated to offer those updates around late spring or June.
In a press release, Boeing confirmed the Air Force’s statements in regards to the need for updated cost estimates.
The engine contract with Rolls-Royce is value $2.6 billion; when the event, integration, test and production of other major subsystems is factored in, the associated fee estimate is roughly $12.4 billion.
Tinker, where all production B-52Hs can be upgraded into B-52Js, can also be preparing for its role in the large modernization effort.
“It’s a large scope of labor, once you include things just like the radar modernization program, the [engine upgrades], integration of advanced extremely high frequency communications, [and] other programs,” Foreman said.
Tinker’s workforce will install the engines, radar upgrades, and other modernizations on B-52s as they cycle through their regular depot maintenance that happens every 4 years, Foreman said.
The Air Force sends about 17 B-52s through Tinker for major maintenance every year, and desires to conduct as many upgrades to the bomber as possible because it moves through the depot. But he cautioned some modernization programs are moving at different timelines and all will not be ready when some bombers undergo.
“We’ve got a master plan that goes tail by tail, that shows over the subsequent 10 years where [a bomber] goes to get modifications along the best way,” Foreman said. “In order we get into the late [20]30s, now we have a fleet of 76 aircraft with recent engines, recent radar, recent [weapons], communications, etc. … The plan is ever-evolving as we gain increasingly more information and individual [modernization] programs move left or right.”
However the upgrades will mean loads more work, and require loads more capability at Tinker, Foreman said. So in 2026, Tinker will start constructing an enormous structure referred to as the bomber agile common hangar that might house 4 B-52s and permit for more upgrading work to be done. That hangar can be ready at the top of 2030, in time for the upgrades of production jets to start in early 2031.
“If you have got aircraft which might be using depot docks for an extended time frame, you wish more docks, and that’s what the agile common hangar brings to us,” Cleaver said.
Foreman said it typically takes a B-52 between 220 and 260 days to undergo depot maintenance, depending on parts availability and whether a bomber has any age-related stress fractures or corrosion that must be repaired. The Air Force continues to be attempting to determine how way more time the upgrades might add to that schedule, he said.
Cracking and other structural issues are common on the six-decade-old B-52, Foreman said, and sometimes require components to get replaced. However the Air Force is used to catching and fixing those problems, he said, and the aircraft should have the ability last well into the 2050s — perhaps to 2060 — without more in-depth structural upgrades.
“We’re very disciplined about [structural integrity] inspections each time [the B-52] is available in” to the depot, Cleaver said. “That’s what’s allowed this aircraft to make it here into the 2020s. But he still has life to take her into 2050 and beyond.”
Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.