USAF oppdaterer B-1B - AW&ST

USAF Upgrade, Service Life Programs Point To New Roles For B-1Bs Steve Trimble  Nearly 18 years of almost continuous deployment as one of the world’s largest and most unlikely close air support aircraft have taken a toll on the U.S. Air Force’s B-1B bomber fleet. One inflight engine fire and two fleet-wide groundings in less than a year underscore the sustained, grueling pace of the last two decades on pilots, maintainers and, not least, the swing-wing aircraft itself. Now a new national defense strategy is reorienting the B-1B fleet. Although it was designed for a “shoot-and-scoot” nuclear-strike mission, the heavy bomber now carries only conventional munitions, including direct-attack, precision-guided bombs and long-range cruise missiles. As the fleet repostures for the more sophisticated adversary role postulated by the Pentagon’s long-term strategy, the Air Force must first address the wear and tear imposed by the activity of the last two decades on the B-1B’s structures and engines, even as some experts call for reassessing the aircraft’s value in the event of a high-end conflict erupting before 2036, the fleet’s scheduled retirement date. But the focus now is mainly on repairs. Starting in fiscal 2018, the Air Force began a program to extend the service life of the bomber fleet’s 289 GE Aviation F101 engines through 2040. As that program got underway, the Air Force also began a structural integrity analysis on the B-1B airframe. One aircraft was used to perform a complete durability test, which revealed a lengthy list of required work to keep the structure airworthy for two more decades. “It’s the main fuselage, the wing roots, the swing-wing gears, elevators,” says Col. John Edwards, commander of the 28th Bomb Wing at Ellsworth AFB, South Dakota. “It’s what we need to do to keep the aircraft in the inventory for 20 years.” The service life extension program (SLEP) for the aircraft will get started by year-end, which is the first quarter of fiscal 2020, he says.

 

New modifications allow the B-1B to collaborate in real-time with short-range fighters. Credit: U.S. Air Force

 

The structural revival for the airframe and engine begins as the Air Force wraps up the most significant systems upgrade for the B-1B fleet since production ceased in 1988. The first B-1B squadron equipped with the Integrated Battle System (IBS) made its first combat deployment last year, arriving in U.S. Central Command to support the campaign against the remnants of the Islamic State group in Syria. In a sign of its advancing age, the Air Force fielded the B-1B in the late 1980s with the same avionics and mission computers as the NASA space shuttle, which were both designed by Rockwell International (now Boeing). In 1993, the Air Force’s decision to remove nuclear weapons from the B-1B included a major investment called the Conventional Munitions Upgrade Program. By the program’s end in 2006, Boeing had revamped the avionics to release flexible load-outs with a wide mix of guided weapons. The aircraft’s original six mission computers—operating a 1960s-era software language called Jovial—were replaced with four new processors running on an updated version of the ADA software code.

 

B-1Bs equipped with color vertical situation displays and fully integrated data links deployed for the first time in 2018. Credit: U.S. Air Force

 

In essence, the nearly $900 million IBS upgrade completes the B-1B avionics refresh by adding modern, color vertical situation displays, fully integrating Link 16 and installing a new troubleshooting alert system for maintainers. The improved connectivity and cockpit displays allow B-1B crews to be active participants in a strike force package for the first time, trading sensor and targeting data with other aircraft during a mission. It is a capability most fighter pilots in the Air Force fleet have taken for granted in the last two decades, but it has finally come to the service’s largest conventional weapons carrier. As the B-1B has evolved, the Air Force faces some decisions as to its direction. Since 2015, the B-1B fleet has been assigned to Global Strike Command, which otherwise manages only nuclear forces. The Air Force has complained about the offensive capacity shortfall caused by the slow replacement of the fighter fleet, so some experts, led by the Air Force Association’s Mitchell Institute, are calling on the service to use its B-1B’s more like long-range, tactical munitions “trucks” than conventional bombers. “The B-1 is effectively a big F-15E for a good portion of the roles,” says Doug Birkey, executive director of the Mitchell Institute. “It makes no sense to us [to] retire B-1s when, with some minor SLEP work, you can keep [them around for] a few more years.”