Here's What You Need to Know: The Pentagon continues to adapt the B-1 to fit its evolving warfighting needs.

Huge yet surprisingly sleek and agile, the U.S. Air Force’s B-1 Lancer strategic bombers—popularly dubbed “Bones” for B-ONE—circles over battlefields in Syria and Afghanistan like angels of death dispensing GPS-guided bombs from on high. Yet the B-1 started out as an over-priced nuclear bomber that was arguably obsolete by the time it entered service. Thus, a bomber designed to dodge Soviet surface-to-air missiles and interceptors found its niche battling Taliban and ISIS insurgents.

During the 1940s and 1950s, the U.S. military sought to push its bombers to ever higher altitudes and faster speeds to protect them from flak guns and fighter planes—pushing new performance envelopes with the pressurized B-29, and later the B-47 and B-52 Stratofortress strategic jet bombers.

But by the early 1960s, the shootdown of high-flying U-2 spy planes over China and Russia by surface-to-air missiles made it clear that altitude no longer offered dependable protection. The Air Force tried developing the huge XB-70 Valkyrie bomber to sustain speeds over three times the speed of sound, but the Soviets countered with the Mach 3-capable MiG-25 Foxbat interceptor. The Pentagon gave up on the Valkyrie in 1962 and began investing more in ground and submarine-launched ballistic missiles to provide nuclear deterrence.

This didn’t sit well with the Air Force, which proposed a new low-altitude penetration doctrine in which supersonic bombers skimmed close to the ground at high speed using new-fangled Terrain Following Systems, making them very difficult to track with radar due to intervening terrain faced by ground-based radars, and the ‘ground clutter’ experienced by airborne radars scanning low-flying aircraft.

The Air Force at first adopted the supersonic F-111 Aardvark to perform this mission, but wanted a larger, longer-range workhorse. The Nixon administration authorized development of a Northrop Rockwell B-1 design which saw its first flight in 1974.

The costly new bomber featured swing wings which could sweep forward to a 15-degree angle to maximize lift during takeoff or landing, allowing the 44.5-meter long plane to operate from shorter forward airbases. To minimize drag for supersonic flight, the wings could tuck inwards to a 67.5 degree angle. At high altitude the four B-1A prototypes could achieve up to 2.2 times the speed of sound-assisted by two flexible vanes situated under the nose that help stabilize airflow.

However, by the mid-1970s the Pentagon was aware of the Soviet Union’s development of new MiG-31 Foxhound interceptors equipped with Zaslon Doppler radars that could sift out ground clutter—making low altitude penetration highly risky. Meanwhile, U.S. B-52s were receiving nuclear-tipped AGM-86 air-launched cruise missiles (ALCMs) that could be launched from well beyond the range of Soviet air defenses.

Advised that the ALCMs were adequate and that the B-1’s concept was outdated, President Jimmy Carter canceled the expensive B-1 in 1977—believing it more sensible to invest in the top-secret B-2 stealth bomber instead. Four years later, a newly-elected Reagan, who had blasted Carter for canceling the B-1, revived the Bones with an order for one hundred aircraft.

This time, the Air Force sought a cheaper, revised B-1B model which could fly further (6,000 miles!) with heavier payloads but at a reduced high-altitude speed of Mach 1.2 (830 miles per hour) or Mach .95 at low altitude. This was because the aircraft’s four F101 afterburning turbofans nestled into the wing roots were no longer designed to swing back with the wings. There was no longer any pretense that the B-1 would outrun fighters and air defense missiles.

Instead, the B-1B’s aluminum and titanium skin surfaces were reshaped and coated with radar-absorbent materials to reduce radar cross-section to just 2.5 meter, roughly that of a small F-16 fighter. Though far from being a “stealth” plane, the B-1 would not be susceptible to detection and targeting at very long range like a B-52 would be.

The crew of four included a pilot, copilot, weapons officer and a defensive systems officer who operated a suite including powerful radar jammers and oversized flares for decoying heat-seeking missiles. An APQ-164 passive electronically scanned array multi-mode radar designed for low-probability of intercept could snoop out the positions of enemy fighters and radars as well as scan the ground for specific targets.

The B-1B had three internal bomb bays allowing it to carry up to twenty-four B61 or 1.2-megaton B83 nuclear gravity bombs between them—each many times more powerful than the atomic bombs dropped on Japan. Alternately, the B-1 could lug up to eighty-four Mark 82 five-hundred-pound gravity bombs, or the equivalent weight in larger bombs. A theoretical maximum bomb load of 125,000 pounds was never implemented operationally.

The first of one hundred B-1Bs built were rushed service in 1987 at the eyewatering price of $250 million each. However, the Lancer suffered a string of early mishaps, ranging from engine fires to the defensive countermeasures jamming the B-1’s own radar. These kept the bomber out of action during the 1991 Gulf War. When the Soviet Union collapsed the same year, the nuclear bomber’s raison d’etre seemed to go with it.

However, the Air Force upgraded the Bones with GPS and the ability to use JDAM precision-guided bombs, and tow ALE-50 decoys to divert hostile radar-guided missiles. Today, the B-1 can also mount up to twenty-four JSOW glide bombs or JASSM stealth cruise missiles with ranges measured in the dozens and hundreds of miles respectively. Meanwhile, the B-1’s nuclear-delivery capabilities were removed entirely in 2011 due to the New START treaty.

The B-1 remains well-liked by pilots for its unusual maneuverability and responsiveness for an aircraft of its size, as you can see in this video. In the early 2000s, Boeing even floated a concept for Mach 2-capable B-1R model using the F-119 turbofans of the F-22 Raptor and armed with air-to-air missiles.

The Bones finally saw action striking targets in Iraq in 1998, then flew out of England to hit Serbian targets during the Kosovo War—delivering one-fifth of all bombs dropped despite flying only two percent of the missions. The B-1’s towed decoys also proved effective, ‘catching’ two deadly 2K12 Kub missiles.

However, the Bones fully came into its own during the U.S. campaign to overthrow the Afghan Taliban in 2001. Afghanistan was simply too far for the Pentagon’s land-based fighters to fly without lots of aerial refueling—but B-1s based in the Indian Ocean island of Diego Garcia could fly over Afghan airspace and loiter overhead for hours at a time.

The Bones brought to the table their huge payload—and their ability to pickle dozens of inexpensive GPS=guided two-thousand-pound JDAM bombs precisely onto targets designated by ground forces. The B-1 thus became a form of flying artillery orbiting overhead, on-call as ground troops ferreted out enemy positions and marked them for destruction. In 2008 B-1s were outfitted with Sniper-XR targeting pods under their noses so they too could designate their own targets.

Bones went on to deliver huge bomb loads in conflicts in Iraq, Libya and Syria. For example, B-1s played an instrumental role in preventing the fall of the besieged Kurdish enclave in Kobane, Syria in 2014, dropping 660 bombs that killed an estimated thousand ISIS fighters. Four years later, Lancers were used to launch nineteen JASSM cruise missiles as part of a punitive strike against Bashar al-Assad.

As of 2017, sixty-two B-1s remain in service with the 7th and 28th Bombardment Wings based in Texas and South Dakota respectively, though aircraft are often operationally deployed to Diego Garcia and Al Udeid air base in Qatar.

Ironically, the B-1s is basically good at the same things the B-52 remains useful for: carrying lots of bombs and missiles over long distances and launching them at adversaries that can’t shoot back. The Bone is faster than the B-52, can carry heavier payloads, has more modern avionics, and is less conspicuous on radar. However, these advantages only marginally improve its survivability versus modern SAMs and fighter. Practically, the Air Force planners want to keep B-1s as far away from these threats as possibly.

The Air Force plans on retiring the B-1 bomber by 2036, while the B-52 is slated to remain active well into the 2040s and possibly beyond. While the B-1 is slightly cheaper to operate at $63,000 per flight hour, the B-1 reportedly is more difficult to maintain (seventy-four man hours of maintenance for every flight hour!) and thus suffers from lower readiness rates of 50 percent. The B-52 comes out to sixty-two hours and 80 percent in these metrics.

Therefore, the Bone may be retired after a respectable half-century of service. Until then, the huge swing-wing bombers will continue to receive upgrades and may yet again be adapted to fit the Pentagon’s evolving warfighting needs—such as potentially hunting ships with long-range missiles.

Sébastien Roblin holds a master’s degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.