The USAF could turn to its supersonic-capable B-1B Lancer strategic bomber fleet to take over as the testbed for air-launched hypersonic weapons to help mitigate availability problems with the Cold War-era B-52H Stratofortress, which is currently in the process of being modernised.
The B-52H was the launch platform for the Mach 5.1-capable Boeing X-51A scramjet testbed, and more recently for the USAF’s AGM-183A Air-Launched Rapid Response Weapon (ARRW), which was once intended to become the Air Force’s first operational air-launched hypersonic missile but was cancelled after a series of failures.
However, due to the ongoing B-52J modernisation programme, eight B-52Hs are expected to be taken from the 76-strong frontline aircraft fleet, with 10-12 more airframes undergoing repair, maintenance or modernisation, leaving just 56 available for operations, including the nuclear deterrence mission. There is a growing recognition that the B-52H fleet can longer be spared to support testing of both the new Hypersonic Attack Cruise Missile (HACM) and Boeing’s experimental HyFly 2 testbed.
Jennifer Wong, head of Bomber Programs at Boeing, has said that this means the B-1B will “become the hypersonic testbed for the Air Force… we can actually not take away from what we’re doing on the B-52 today to have it test hypersonics.”
The B-1B’s eight external hardpoints – which were originally provided to carry AGM-86B Air-Launched Cruise Missiles (ALCMs) – were inactivated as part of the New START nuclear arms treaty, but six of these are now being reactivated and Boeing has designed a new Load Adaptable Modular (LAM) pylon, which allows weapons of up to 7,500lb to be carried on each hardpoint. The LAM is adaptable too, with adjustable mounts and attachment points that can “click into a new position, like Lego,” allowing them to be changed to carry different types of weapons on the flightline.
Boeing has built four of the new pylons using its own funds but expects an order for more; perhaps suggesting that there may be an eventual requirement for an operational capability using the new pylons, which could (for example) double the number of 2,000lb Joint Direct Attack Munitions (JDAMs) carried, or add 12 HACMs to the B-1Bs armoury.