The Marine Corps' F-35B Joint Strike Fighters led a big part of the campaign to demolish Islamic State terrorists in recent months, outpacing the combat flight hours flown by older aircraft on past deployments by 2-to-1.

Members of Marine Fighter Attack Squadron 211 flew 1,200 combat hours over Iraq and Syria, "making up a considerable portion of the ordnance that was dropping in theater," said Col. Chandler Nelms, commander of the 13th Marine Expeditionary Unit.

"They were very active and did very well," he told Military.com. "As the MEU commander, anytime I see aircraft flying that much, I get concerned about what the breaking point is going to be. But there's no breaking point with these guys; they just crushed it."

The Marines spent more than seven months deployed to the Pacific and Middle East. The F-35B detachment was assigned to the 13th MEU, which operated from aboard the amphibious assault ship Essex. It was the first time the Marine Corps' variant of the stealth jet, which can take off and land vertically, deployed to the Middle East.

The F-35B's first combat strike was in Afghanistan in September, where the Marine pilots were flying close-air support missions, said Lt. Col. Kyle Shoop, VMFA-211's commanding officer.

From there, they flew more than 50 days' worth of close-air support and defensive counter-air missions in Iraq and Syria.

"Every day, [the pilots] were supporting over six hours of time in theater," Shoop said.

The Marines were prepared for a higher-level fight had they been provoked by other actors in the region, he added. Their encounters with pilots from Russia, which is supporting Syrian President Bashar al-Assad's forces, were minimal though, he said.

"We were aware they were airborne," Shoop said. "There are some established de-conflictions that are already set up between Russian and U.S. forces. They were all adhered to, but we were aware."

The F-35Bs were able to give troops on the ground more information than would have been possible in the AV-8B Harrier jump jet, which the Joint Strike Fighter will eventually replace. Its sensors are better in poor weather, Shoop said.

The Marines ended up flying the F-35B about twice as much as the Harrier flew on past deployments, Nelms said.

"A conservative estimate is the F-35 flew 100 percent more hours on this deployment than a typical deployment for a Harrier squadron," he said. "When you consider that their readiness was 75 percent or better ... while doubling the amount of flight hours being flown, it's a real testament to the aircraft and the maintainers."

The F-35B pilots weren't the only members of the MEU supporting the fight against ISIS. A CH-53E Super Stallion heavy-lift helicopter provided airlift in Iraq, Nelms said, and an artillery battery deployed to Syria with M777 howitzers.

"It was an exciting time to be doing so many different things," he said.

The MEU is expected to return to California this week.

-- Gina Harkins can be reached at gina.harkins@military.com. Follow her on Twitter @ginaaharkins.