(Hypersonic weapon demonstrations will build on experience gained during tests of the X-51A Waverider. Credit: U.S. Air Force)
⏩ ARRW and HCSW hypersonic B-52 demos to be accelerated under Section 804
⏩ Preparations for B-52 TBG and HAWC DARPA demonstration tests underway
⏩ New multilaunch, higher-capacity pylon concepts under study
The B-52H’s ample wing and external load-carrying capability have contributed to the aircraft’s prominent role in hypersonic testing and, as a result, the bomber’s future is closely tied to the upcoming demonstration and deployment of the U.S. Air Force’s first-generation hypervelocity strike weapons.
With major upgrades underway and reengining planned to sustain the B-52H to 2050, the Air Force intends to retain the long-serving bomber as the mainstay of its long-range strike fleet alongside the new Northrop Grumman B-21s as they are delivered beginning in the late 2020s. In particular, the B-52 is set to play a major role in enhancing standoff capability because rocket-boosted and air-breathing hypersonic weapons will be large, making them a challenging store for internal carriage.
“On hypersonics, there are several activities going on, mostly in terms of different types of weapons demonstrations,” says Boeing Bombers Program Manager Scot Oathout. “The B-52 is in the middle of those as the technology and the two approaches to hypersonics mature.” The program is involved in much of that flight test and evaluation. It is a very fluid and dynamic world we are in now, he notes.
The Air Force says the B-52 “is scheduled to be the launch platform for several hypersonics weapons demos in the 2019-20 time frame,” and adds that in view of the urgency placed on these efforts, two of them are being accelerated for rapid prototyping under the Pentagon’s new Section 804 approach to acquisition policy. These are the Lockheed Martin AGM-183A Air-Launched Rapid Response Weapon (ARRW) and Hypersonic Conventional Strike Weapon (HCSW). “The expected success of one or more of these hypersonic programs would not change the mission of the B-52, but only enhance its long-range strike capability,” the service explains.
Nearer-term testing already is planned for DARPA’s Tactical Boost Glide (TBG) demonstrator, a rocket-powered Lockheed Martin hypervelocity glider that provides the basis for the AGM-183A. The TBG is scheduled for flight tests in 2019 while the follow-on rapid-response weapon is targeted at early operational capability in 2021. The solid rocket-powered HCSW meanwhile is slated to enter initial service in 2022.
The Air Force’s air-breathing hypersonic weapons are powered by scramjet engines, prototypes of which were launched by a B-52 during NASA’s X-43 tests in the 2000s and by the follow-on Air Force/Boeing X-51A in 2010-13. Lockheed Martin’s Skunk Works and Raytheon are working under contract with DARPA to develop the conceptually similar Hypersonic Air-breathing Weapon Concept (HAWC). Flight tests of the winning HAWC design on a B-52 are expected to begin before fiscal 2020.
Regardless of the mix of final configurations, “the B-52’s future is enhanced by that potential capability,” Oathout says. “It is a big truck and easy to modify to carry extremely large things long distances, so it fits well with that profile well into the 2040s and 2050s and whatever technology that brings us.”
To prepare for the larger weapons, Boeing and the Air Force are studying “enhanced carriage options and exploring different pylons,” Oathout says. With the B-52 having carried such external loads as the 10,150-lb. AGM-28 Hound Dog supersonic missile and special-mission heavyweights such as the D-21 stealth drone and X-15 hypersonic test aircraft, the design team now is studying configurations to increase capacity for multiple high-speed weapons. “We are looking at more than a single carriage type of pylon,” Oathout explains.
Moves in this direction were signaled in June when Air Force Materiel Command issued a request for information on a new external weapons pylon that will take the B-52’s current 10,000-lb. maximum external load (across two underwing pylons) to 40,000 lb. The new pylon is planned to succeed the current Improved Common Pylon, which has been in service since the 1960s. “When it was introduced, there wasn’t a requirement nor did anyone foresee a need to carry weapons heavier than 5,000 lb.,” adds the Air Force, which is targeting a development to fielding time of 36-72 months
(Guy Norris, Aviation Week)