For almost five months, B-1 crews from the 9th Bomb Squadron at Dyess Air Force Base, Texas, focused on one town — Kobani in Syria — in the battle against the Islamic State group.

Kurdish forces had become were entrenched in their own city as waves of Islamic State fighters advanced.

The enemy was "sending troops there constantly," said a weapons systems officer from the 9th Bomb Squadron identified for security reasons only as Scram. "They were very willing to impale themselves on that city."

That made the battle site target-rich: There were fighters out in the open and on top of buildings and bridges.

The B-1 was right for the fight. It can carry up to 84 500-pound general-purpose bombs, or a combination of dozens of other weaponry of similar weight. It can loiter on station for up to 10 hours with a single air refueling. The U.S. airmen could stay on station for hours, taking on targets from Kurdish forces and developing their own targets to push the fighters out.

The squadron dropped about 660 bombs on Kobani, about one-third of all the bombs it dropped during the first five months of Operation Inherent Resolve. The squadron says those bombs killed more than 1,000 Islamic State fighters.

"To be part of something, to go out and stomp these guys out, it was completely overwhelming and exciting," a B-1 pilot identified as Maj. Johnson said.

By the time the 9th Bomb Squadron completed its deployment in late January, the Kurdish troops had declared victory and claimed Kobani. Islamic State fighters, in speaking to IS-aligned news network Amak in Syria, said the constant airstrikes forced them to withdraw from Kobani.

"I swear by God, their planes did not leave the air, day and night; they did airstrikes all day and night," an Islamic State fighter told the news agency, according to CNN. "They targeted everything. They even attacked motorcycles; they have not left a building standing. But by God willing we will return and we will have our revenge multiplied."

Kobani is still under Kurdish control.

That victory is memorable in the now yearlong battle in which the Islamic State has been able to keep its ranks filled and hold on to land — despite the intervention of U.S.and coalition forces. Officials expect the fight to last years.

Expanding mission

The 9th Bomb Squadron crew members who flew the first bomber mission in the fight against the Islamic State learned of their orders just minutes before they took off.

The squadron’s B-1Bs had deployed in July 2014 to Al Udeid Air Base, Qatar, in support of the winding down mission in Afghanistan. The crews followed news of the advance of the Islamic State through Iraq and Syria, with many choamping at the bit to do something.

On Aug. 8, 2014, U.S. crews did something, with fighters and bombers tasked to begin Operation Inherent Resolve. Orders came to a 9th Bomb Squadron B-1 as it was taxiing toward a runway.

"The crew was planning to fly to Afghanistan," Maj. Johnson said in an Air Force Times interview. "They were given essentially a last-minute change right before the runway and then headed in the other direction."

The crew was young for this deployment. It was the first combat deployment for many of the airmen, and it started relatively slowly with its focus on Afghanistan.

Johnson, however, had deployed to Iraq before in 2010. He had helped train the Iraqi Air Force, teaching pilots to fly T-6s at a base near Tikrit. When he flew bombing missions in 2014 in north Iraq and in Syria, he flew over that air base.

"For me, there was this weird kind of déjà vu of seeing these places, seeing Tikrit, among others," he said. "The airfield I had been stationed at, unknown at the time when I was overflying it, had been overrun by Daesh [Islamic State]."

For crews used to flying missions in Afghanistan, the fight against the Islamic State was different. They faced targets in urban environments, and an enemy force focused on advancing and taking over large landmarks.

Unlike the missions the B-1 aircrews had gotten were used to in Afghanistan, there were no American boots on the ground calling in airstrikes. Instead, the crews relied on a mix of Kurdish troops, coalition surveillance and their own sensors to identify targets.

"It was very different, in a sense. You see a lot more buildup in Iraq," a B-1 pilot identified as Capt. J said. "From cities, flying over Baghdad and flying over towns. There's a mix of scenery, it's maybe more enjoyable to see towns and cities. And to see the Mosul Dam itself, and the big reservoir they have. It's kind of a neat sight with all the water out in the middle of the desert. It seems out of place, but there it is."

The B-1s were first tasked under Operation Inherent Resolve with flying on-call support over Baghdad in support of Iraqi forces, but the mission slowly expanded as the Islamic State advanced. In the first month of airstrikes, coalition aircraft dropped 211 bombs. In January, when the squadron finished its deployment, coalition aircraft dropped 2,308.

The ops tempo early in the operation was staggering for the airmen compared with recent activity in Afghanistan. Aircrew would fly twice in 60 hours, with missions lasting up to 10 hours. Including preparation and debrief, duty would typically fill all 24 hours of a day.

Maintenance airmen would routinely work up to 15 hours to fix and turn around a jet to get ready for the next flight.

Going 'Winchester'

In the military operations world, it's called going "Winchester."

The term refers to a military asset expending all of its weapons. When a B-1 returns to base without a single bomb on board, the crew on the ground slaps a "W" sticker inside the bomb bay doors to note the mission.

For the 9th Bomb Squadron's deployment in support of Operation Inherent Resolve, weapons airmen slapped 31 "W" stickers on the insides of their B-1.

"There's nothing cooler than seeing the jet come home Winchester, and especially getting to stick that sticker under the door,"a B-1 crew chief identified as Sgt. Barnes said.

In all, the squadron dropped more than 2,000 joint direct attack munitions during its six-month rotation, a number that was "way, way more" than the squadron had dropped on any six-month rotation since at least 2010.

The Winchester missions were among the most difficult for pilots and aircrew, and for the weapons builders and maintainers on the ground tasked with fixing and reloading the B-1s.

For Capt. J, one of those missions came as he flew with his college roommate, who had becoame his co-pilot. On a mission several hours long up to Kobani, the crew identified targets and "emptied the jet."

That mission helped support a Kurdish advance in the city.

Despite the intense work and long hours, morale was high because the crews knew the mission was important.

"You are not just turning wrenches and putting guys into a state of fatigue for no reason, you are actually supporting a higher objective," Maj. Johnson said. "You are getting to see the benefits of your work each and every mission."

Deliberate targeting

U.S. officials have maintained the deliberate targeting, and strict rules of engagement have limited civilian impact. However, Airwars, an independent group tracking the airstrikes, released a report this month stating that coalition airstrikes have likely killed at least 459 civilians over the past year. Fifty-seven specific strikes killed civilians, and caused 48 possible "friendly fire" deaths.

The Pentagon, in response to the report, said the military works hard to be precise in its targeting and it investigates accusations of civilian casualties. U.S. Central Command has investigated four incidents of alleged civilian casualties, finding that three did not involve civilian deaths and two innocent civilians were killed in the other, according to The Associated Press.

Saving Kobani

The air power wasn't the main key to the victory in Kobani, according to the Dyess airmen. It was the Kurds themselves, and their ability to fight will continue to be a deciding factor in the future of the operation.

"There were times we were bombing across the street, and as soon as the weapons were going off, they are charging into the rubble to take out what's left and move forward that line of troops to the next block," Maj. Johnson said. "It's an amazing job the [Kurdish forces] did and how they are, more so than air power, critical to victory in Kobani."

That victory is the squadron's biggest takeaway from the deployment.

"I look forward to telling my grandkids that I got to help these people to fight off [the Islamic State] and to defend their homes," Capt. J said.