As U.S. troop levels thin out in Iraq, Hawaii’s combat presence in Afghanistan is bulking up.

With dozens of Black Hawk and Chinook helicopters flanking them, more than 2,000 25th Combat Aviation Brigade soldiers stood at attention Friday in a deployment ceremony at Wheeler Army Airfield as they prepared to leave for a year of duty in southern Afghanistan.

About 2,600 soldiers will be deploying from Hawaii, along with all of the unit’s roughly 90 Black Hawk, Chinook and Kiowa Warrior helicopters.

The aviation brigade, which will pick up more than 400 soldiers and Apache attack helicopters from Colorado, will be based out of Kandahar, Tarin Kowt in Uruzgan province, and Forward Operating Base Wolverine in Zabul province, officials said.

Already serving in eastern Afghanistan are 3,500 Schofield Barracks infantry soldiers with the 3rd Brigade Combat Team, meaning 6,100 Hawaii soldiers will temporarily overlap in the country early next year after the aviation brigade deploys in January.

Many of the aviation soldiers will have December off. Brigade commander Col. Frank Tate told more than 800 people present for the official send-off that the aviation unit’s motto is "Lele Makou no na Puali" ("We Fly for the Troops").

"We fly for the troops in the dark of night, in the heat of day, in challenging weather, over harsh terrain, in hostile territory," Tate said.

Tate said it will be the helicopter brigade’s fifth deployment since 2001, with duty that year in Bosnia, followed by Afghanistan and Iraq in 2004-2005, Iraq in 2006-2007 and Iraq again in 2009-2010.

"It’s been a busy 10 years for the Wings of Lightning team," Tate said. "We could not have sustained that pace nor have accomplished so many vital missions without the love and support of our families and our Hawaiian ohana."

Chief Warrant Officer 4 Joseph Roland, the brigade’s senior instructor pilot, said choppers are "in great demand (in Afghanistan), even more so than when we were in Iraq, just due to the terrain. It is the key way to move people and equipment throughout that country."

Mountain flying is challenging, and militants occasionally have shot down helicopters with rocket-propelled grenades, including a Chinook helicopter on Aug. 6 in Wardak province, killing 30 Americans, including 25 special operations personnel.

Nicole Villegas, two months pregnant and among hundreds of spouses attending the deployment ceremony, sat in the front row of a bleacher section with her 3-year-old daughter behind more than a dozen baby strollers.

Her husband, Sgt. Benito Villegas, a 27-year-old from Maryland who works in flight operations, is deploying for the first time to Afghanistan after serving twice in Iraq.

"Well, it’s going to be hard because I’m pregnant," she said. "So far, I’m OK. I trust the people he’s with, but I don’t trust where he’s going. It’s a very hostile area for the most part."

Among those deploying is Black Hawk pilot 1st Lt. Blake Brostrom, 25, a University of Hawaii graduate and brother of 1st Lt. Jonathan Brostrom, who was killed in the highly publicized 2008 Battle of Wanat in eastern Afghanistan, which claimed nine U.S. lives with 27 wounded.

"It’s definitely going to be a different experience," Brostrom said of the upcoming deployment. "I can’t say at all what I’m going to feel like because I’m not there yet. I’ll definitely be cautious before I make any rash decisions or anything like that."