US B-52 bomber fleet to get powerful hypersonic missile upgrade, new engines

The United States Air Force’s (USAF) venerable B-52 “Stratofortress” fleet is to get another round of upgrades to extend its life and enable it to carry hypersonic missiles. The new parts will include brand-new engines, avionics, and other gear that could well mean the aircraft hits a century in service.

The B-52, also known as “big ugly fat fellow” or Buff, is the USAF’s primary long-range, large-payload multirole bomber. It serves as the nation’s principal strategic nuclear and conventional weapons platform.

First entering service in 1952, the B-52 celebrated its 50th anniversary in 2002 and is now officially the longest-serving combat aircraft in the world. The new upgrades will further extend its illustrious service well into the 1940s.

The upgrades are necessary for the newly proposed B-52 variant, the B-52J. One of the most significant changes from the existing B-52H variant will be replacing its Pratt & Whitney TF33 engines with new Rolls Royce F130 engines.

B-52J to serve well into the 2040s

This upgrade will boost fuel efficiency by as much as 30% and is to be fitted under the USAF’s Commercial Engine Replacement Program. After completing the works, the new B-52J should also be able to field the Hypersonic Attack Cruise Missile (HACM).

This is a scramjet-powered hypersonic missile capable of speeds over Mach 5. The upgrades considered the biggest in the aircraft’s over 70-year service history , will be received by all 76 of the surviving B-52 fleet.

Over 740 B-52s were originally ordered and built, but this number has gradually been retired over the years. Today, only around 10% of this number remains in active service, with many older airframes mothballed in case they are needed.

The B-52H is an extremely large aircraft, measuring 159.4 feet (48.5 meters) in length. Its approximate weight is 183,535 pounds (83,250 kg), and its maximum take-off weight is 488,000 lb (220,000 kg).

The aircraft’s all-metal skin carries a significant portion of the flight load. While on the ground, the front section of the fuselage looks wrinkled, but the skin expands and becomes smooth as the crew compartment pressurizes during ascent to altitude.

Death from above; lots of it

The current B-52H has a weapons payload of more than 70,000 pounds (31,752 kg) and can carry the most diverse range of weapons of any combat aircraft. Its nuclear weapons capacity includes 12 AGM-129 advanced cruise missiles, 20 AGM-86A air-launched cruise missiles, and eight bombs.

According to Airforce Technology , the B-52H’s conventional weapons payload includes eight AGM-84 Harpoon missiles, four AGM-142 Raptor missiles, 51,500 lb bombs, 301,000 lb bombs, 20 AGM-86C conventional air-launched cruise missiles, 12 joint stand-off weapons (JSOW), 12 joint direct-attack munitions, and 16 wind-corrected munitions dispensers (WCMD).

Additionally, the B-52H can deliver 51,500 lb, 301,000 lb, and 202,000 lb navy mines.

Regarding the HACM , the USAF awarded a contract to RTX subsidiary Raytheon in 2022 for a weapon with a scramjet supplied by Northrop Grumman. The HACM is based on previous work done with DARPA and continues a partnership with Australia. The Air Force has stated its intention to deploy the weapon by 2027.