The B-1B bomber, known to its crews as the “Bone,” has been a mainstay of close air support and other strike missions over Afghanistan and Iraq. - Photo by U.S. Air Force / STAFF SGT. DOUGLAS C. BRUNELLE

The huge, swing-wing airplane is nothing if not flexible -- canceled, revived, converted from nuclear strike plane to conventional bomber and then to a flying arsenal for the GPS-guided bombs on which ground troops fighting for their lives in Iraq, Afghanistan, and now Syria often rely.

And if the Air Force's supersonic B-1B bomber is one other thing, it's misunderstood.

It's no secret that the B-1B bomber, officially called the Lancer but known to its four-man crews as the "Bone," had a troubled early life. Canceled by President Jimmy Carter and revived by successor Ronald Reagan, the B-1B underwent redesigns before it reached Air Force crews in the mid-1980s, and even then, the revamped airplane suffered a string of high-profile malfunctions and crashes.

Not until 1998, three decades after the distinctive swing-wing bomber was first designed, did the B-1B first drop bombs on enemy targets in Iraq.

In public forums, the B-1B has often been a punch line. A glowing feature in The New York Times earlier this month on the B-1B's older, slower brother, the gangly B-52, highlighted the tribulations of the supersonic bomber's development, comparing it unfavorably with the reliable B-52 of Dr. Strangelove fame, which has been in uninterrupted service since the 1950s.

And during a Senate hearing in 2014, Sen. John McCain, R-Ariz., pushed back hard on Secretary of the Air Force Deborah Lee James' description of the B-1B as an effective airplane for "close air support," which is the delivery of precision-guided bombs in support of embattled ground troops. "That's a remarkable statement," McCain scoffed. "That doesn't comport with any experience I've ever had, nor anyone I know has ever had."

What McCain didn't seem to be aware of, and what the Times report failed to note, is the long third act of the B-1B's life. It was converted in the 1990s from a Soviet-airspace-penetrating nuclear strike plane to a conventional bomber to pound the infrastructure and massed soldiers of an enemy army.

The "Bone" converted again in the aftermath of the Sept.11, 2001, terror attacks on the U.S. into not just a close air support plane, but, by all accounts, a successful one.

A YouTube video on a B-1B strike in Afghanistan's violent Pech Valley and the profanity-laden commentary of the ground troops doing the filming gives a sense of the role the big bomber has played supporting troops in Iraq and Afghanistan.

In the video, originally uploaded to YouTube by a military spokesman, troops at a remote base watch as three satellite-guided bombs from a B-1B strike mountainside targets almost simultaneously, followed seconds later by a fourth. The soldiers express their elation in colorful terms.

By the time of the airstrike depicted in the video, B-1B pilots had been flying their dark-gray planes 20,000 feet over Afghanistan for years, since the opening night of the U.S.-led air war in October 2001. Five B-1Bs flying out of the Indian Ocean outpost of Diego Garcia joined 10 B-52s and two B-2 stealth bombers in pummeling the Taliban regime's few fixed-site targets in that 2001 mission.

One pilot who flew B-1Bs in the early months of the Afghan war, Jordan Thomas, had been working at the Air Force's B-1B training school the summer before the 9/11 attacks when he fielded what seemed at the time like an odd inquiry from a congressional staff member. At the time, part of the B-1B fleet was on the chopping block as a cost-cutting measure.

"This staffer asked whether it was true that the B-1 wasn't able to fly over high mountains like in Afghanistan, which he'd read somewhere," Thomas remembered. "I wrote back, 'We can fly over the mountains of Afghanistan, but why on earth would we?'"

Working with fellow B-1B pilots in the skies over those very mountains and back on Diego Garcia, Thomas helped the B-1B crews develop what would become an essential skill in the years ahead: coordinating with ground troops to drop firefight-ending bombs with lethal precision and accuracy. "We were given an opportunity in Afghanistan to prove what the B-1 could do," Thomas said.

The plane's success in aiding the ouster of the Taliban gained it a moment of appreciation and saved the B-1B fleet from the cuts that Defense Secretary Donald Rumsfeld, a B-1B skeptic, had been pressing before the 9/11 attacks. "Maligned B-1 Bomber Now Proving Its Worth," a Los Angeles Times headline trumpeted two months into the bombing.

Day-to-day coverage of the fall 2001 air campaign, though, emphasized the B-52. The B-1B was mentioned only occasionally, even though B-1Bs and B-52s were flying roughly equal numbers of missions and the newer B-1Bs were outpacing their older siblings in numbers of bombs dropped, especially smart bombs.

The misrepresentation bothered some of the B-1B pilots on Diego Garcia. Thomas had a theory about what was going on. Because the B-52s flew mostly during daylight hours and the B-1Bs mostly at night, journalists accompanying the Northern Alliance troops on the ground could only see and photograph the B-52s, and they mistakenly assumed that the same planes were carrying out the night bombardments.

In the years that followed, the B-1B became a mainstay of close air support and other strike missions over Afghanistan and Iraq. A B-1B kicked off the air war in Iraq in 2003 with a string of bombs intended to kill Saddam Hussein in one of his Baghdad palaces. (It turned out, he wasn't there.)

"We are using it in ways never conceived of previously," James Roche, then secretary of the Air Force, said of the B-1B later that year. Capable of flying in rougher weather than the B-52, cheaper to operate and capable of carrying more bombs, the B-1B displaced the B-52 in 2006. It became the standard bomber deployed to support ground troops in the two wars, while the older aircraft played the traditional nuclear deterrent role.

One unit whose veterans sing the B-1B's praises is the 2nd Battalion, 503rd Infantry Regiment, which -- during 15 months in the Pech Valley and adjoining Afghan valleys in 2007-8 -- became the most heavily decorated Army battalion of the post-9/11 wars.

"Our favorite asset at the company level was the B-1," said one of the unit's company commanders, Lou Frketic. "They had more ordnance and longer loiter times, and they delivered ordnance to the desired location without trying to second-guess us with their own optics."

"What I loved about the B-1 was that it had such incredible payload capacity and such incredible time on station," the battalion's fire support officer, Jeffrey Pickler, said. "We dropped over a million pounds of Air Force bombs, and a lot of that was B-1s."

When insurgents attacked from rock formations high in the mountains, U.S. troops first fired artillery and mortar rounds to get the enemy to take cover. Then bombs from a B-1B or another airplane would smash the militants' natural bunkers before attack helicopters arrived to pick off survivors.

As with the AC-130 gunship that destroyed an international hospital in Afghanistan this fall, the B-1B's destructive power is a double-edged sword. If it strikes the wrong target, the damage can be severe.

"It was like Judgment Day," a survivor of an errant 2008 B-1B strike that killed dozens of civilians told Human Right Watch. And in June 2014, a B-1B dropped a bomb on a special operations team in Afghanistan, killing five U.S. soldiers and one Afghan. That error was chalked up to a misunderstanding by the bomber's crew of how far away the plane's sensors could detect the ground troops' identifying infrared strobe lights.

When targeting pods with high-tech surveillance cameras were added to B-1Bs in 2008, "it transformed the nature of the aircraft," according to retired Lt. Gen. David Deptula, an airpower advocate who flew B-1B and B-52 bombers while he was on active duty.

Besides dropping bombs, which they could do with more precision than B-52s, B-1B crews gained the ability to watch over ground troops' shoulders for potential threats, supplementing the stressed fleet of Predator and Reaper drones designed for that purpose.

The first B-1B crew to drop bombs in America's latest air campaign over Iraq got the call one day in August 2014. Already on the runway for a routine mission over Afghanistan, according to an Air Force Times report, the crew plugged in new coordinates and headed for the skies around Baghdad to support Iraqi ground forces.

As the U.S.-led bombing campaign against the Islamic State expanded, it became the focus of a full squadron of B-1Bs. On 31 occasions, the aircraft dropped all of the bombs they had on board on their targets.

Of the missions in which the pilots dropped all their bombs, many took place over the northern Syrian city of Kobani. In an air campaign whose slow pace has drawn criticism, the four-month bombardment of Kobani stood out for its punishing tempo. The B-1B was at the heart of it, dropping bombs as directed by rear-area U.S. air controllers who relayed strike requests from Kurdish troops on the ground.

The Islamic State's grip on Kobani broke last January.

The next B-1B squadron to deploy to the Middle East played a similar role, supporting ground offensives by Iraqi troops in Tikrit last spring. "We kill bad people and we break their things, and we're very good at it," the squadron's commander told a South Dakota journalist after the unit's return home.

A third squadron of B-1Bs was used in the retaking in November of Sinjar, in between the Islamic State strongholds of Mosul and Raqqa, by Kurdish forces.

"We focused first on northern Syria, then northeastern Iraq, then Sinjar," the currently deployed B-1B squadron's commander told The Washington Post.

The officer's 37th Expeditionary Bomb Squadron has struck Islamic State command posts, training camps and oil production facilities, he explained. But the most satisfying missions have been those in direct support of friendly ground troops in both countries, most recently around the embattled Iraqi city of Ramadi.

That was where, in a particularly memorable recent mission, Iraqi troops requested that the squadron commander and his crew do something about small boats that Islamic State fighters were using for transport.

Watching with their targeting pod, the crew waited until the boats clustered under a bridge and then destroyed the bridge with satellite-guided bombs. "That was different," the B-1B squadron commander said. "I never expected to be dropping ordnance on boats."

A single B-1B can drop as many bombs on Syrian and Iraqi targets as 40 attack jets flying off an aircraft carrier in the Persian Gulf, one retired Air Force general said, making the bomber's importance to the air campaign obvious. "The B-1 carries so much payload, and has so much endurance, its persistence can't be matched by other platforms" like smaller attack jets and the B-52, he said. "It is both more effective and more efficient."

SundayMonday on 01/03/2016