The U.S. Air Force is planning to keep its fleet of 76 Boeing B-52H Stratofortress bombers in service until at least 2050, when the youngest aircraft will be 88 years old, reports Aviation International News Online. The USAF will operate these B-52s alongside at least 100 Northrop Grumman B-21 Raider stealth bombers, while the newer Rockwell B-1B Lancers that augment the B-52 today will retire in 2025-2035, followed by the small fleet of Northrop Grumman B-2 Spirit bombers. The majority of the parts for these upgrades will be U.S. made.
To facilitate this, the venerable “Buff” is undergoing a series of upgrades, including the installation of new engines and new attack radars, and perhaps improvements to the B-52’s sensors, avionics, defensive aids suite, crew escape systems, and flight data recorder, in addition to relocating or replacing the Sniper targeting pod.
These potential new upgrades will build on recent and ongoing modernization and modification programs, including the modification of the bomb bay’s common rotary launcher to allow the simultaneous launch of more smart weapons from the internal bay (combat-proven in November 2017) and the Combat Network Communication Technology (CONECT) upgrade that added digital display screens, computer network servers, and real-time beyond-line-of-sight communication links. Link 16 will be integrated from 2020. All of these improvements could potentially result in the allocation of a new B-52J designation.
In total, the service has allocated nearly $2.1 billion for development and over $1.3 billion for the production of B-52 modernization and capability improvements over the next five years. The most important elements in the planned upgrade will center on the provision of new engines and radars.
The Air Force considers the B-52H’s TF33 turbofan engine to be "inefficient and [of] limited capability compared to modern commercially available engines" and "costly and manpower-intensive to maintain.” It is also facing increasing obsolescence issues. The Air Force has conducted 13 studies examining B-52 re-engining options since 1996. Initially, attention was focused on replacing the eight original 17,000-pound thrust low-bypass ratio Pratt & Whitney TF33-PW-103 turbofans with four much bigger, higher-bypass ratio, higher-thrust turbofans (perhaps the PW2000 or the Rolls-Royce RB211) but the USAF now intends to replace the TF33s with eight engines of a similar size, weight, and thrust rating, using the existing nacelles and minimizing the need for structural modifications. The aim is to reduce maintenance costs and improve fuel efficiency by at least 20 percent, while maintaining ceiling and takeoff performance.
Some $727.5 million has been allocated for the development phase of the re-engining project between Fiscal Years 2019-2023 with $550 million for the production phase, starting in FY2022. The Air Force plans to select the new engine in the third quarter of FY2019 (the end of June 2020) and will test the new engines on two B-52s from 2022, before acquiring 74 more engine sets from FY2026, completing the re-engining project by 2034.
Rolls-Royce is proposing the 17,000-pound-thrust F130 version of its BR725 turbofan, as used in the Gulfstream G650 business jet. Earlier versions of the F130 are in U.S. Air Force service on the Bombardier Global Express-based E-11 BACN (Battlefield Airborne Communications Node) aircraft (having amassed approximately 200,000 combat hours) and on the Gulfstream G550-based C-37 VIP transport aircraft. If the F130 engine is selected for the B-52, the majority of parts will be U.S.-made and the engines will be assembled and tested in Indianapolis, Indiana.
General Electric will offer the 18,000- to 20,000-pound thrust CF34-10 engine (used by various regional airliners) or the similarly rated Passport engine in the Bombardier Global 7500 business jet. Pratt & Whitney has offered an overhaul of the TF33 as a lower-cost alternative to new engines, but could also offer a new engine.
The USAF hopes to replace the B-52’s mechanically scanned Northrop Grumman AN/APQ-166 radar with a modern Active Electronically Scanned Array (AESA) set. Such an AESA upgrade would give improved range and simultaneous target engagement capabilities, as well as enhanced datalink and electronic attack capabilities. Northrop Grumman has offered the AN/APG-83 scalable agile beam radar (SABR) system for the B-52, while Raytheon is offering an AESA based on technology and hardware from the AN/APG-63(v)3, AN/APG-79, and AN/APG-82.
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