The Army will inactivate the 159th Combat Aviation Brigade this year, officials announced Thursday.

The 159th CAB is the first of three aviation brigades expected to be cut as part of a five-year aviation restructuring initiative. The other two have not been announced.

The 159th, which recently returned from Afghanistan, is one of two combat aviation brigades in the 101st Airborne Division at Fort Campbell, Kentucky.

"Fort Campbell is the only installation where we've got two aviation brigades," said Col. John Lindsay, director of aviation for the Army G-3. "Following the inactivation of [the 159th], we'll have the 101st [CAB] on hand to continue to support training and operational requirements for the 101st Airborne Division."

Fort Campbell will lose about 2,400 soldiers as part of the 159th CAB inactivation. The inactivation is scheduled to be completed by the end of fiscal year 2015, which began Oct. 1. Lindsay said he estimates it'll take nine to 10 months to complete the inactivation.

Most of the soldiers in the brigade will be reassigned to new units — some of them within the 101st Airborne, Lindsay said.

"That will help minimize some of the associated turbulence," he said. "We're particularly sensitive to the importance of taking care of our soldiers and families in this unit, and we want to make sure we give our leaders the appropriate amount of time to ensure the proper transition for these soldiers."

Cutting three combat aviation brigades will leave the Army with 10 CABs in the active force. The reserve component will retain its 12 aviation brigades — 10 in the National Guard and two in the Army Reserve.

These inactivations are the latest in a series of cuts the Army is making as it draws down to an end-strength of 490,000. So far, the Army has announced 13 brigade combat team inactivations and a massive restructuring of its remaining BCTs. More cuts could follow if the Army has to shrink even further because of budget cuts.

To meet the new budget restrictions, the Army is implementing a five-year aviation restructuring initiative that calls for the service to divest its fleet of the OH-58 Kiowa Warrior helicopter and use the AH-64 Apache to fill the Kiowa's reconnaissance and scout role.

The Army would pull Apaches from the Guard inventory to fill the gap, and, in turn, provide the Guard with UH-60 Black Hawk helicopters.

The plan has been controversial among many Guard advocates, but Army officials said it's necessary to save money and retain a ready, effective aviation force.

As part of the restructuring, the Army will retain the 159th CAB's Apache battalion, the 3-101 Attack Reconnaissance Battalion, and reassign it to the 101st CAB, Lindsay said.

This will give the 101st CAB two attack battalions, each with 24 Apaches, he said.

One will be an attack reconnaissance battalion, which will be partnered with the MQ-1C Gray Eagle unmanned aerial system for an attack mission. The other will be an attack reconnaissance squadron tasked with pairing with the RQ-7 Shadow to take on a reconnaissance mission, Lindsay said. The squadron is designed to replace the Kiowa element within the brigade.

"One of the things we're doing with the aviation restructure is we're streamlining all of our units and trying to get them into the same shape," Lindsay said. "Right now, we have seven different types of organizations, so there's a variance in the units. What we're attempting to do … is to streamline these organizations so we have a standard package."

To date, the Army has inactivated one Kiowa squadron, the 4-6 Attack Reconnaissance Squadron at Joint Base Lewis-McChord, Washington. There are nine squadrons, including one in the Guard, remaining, Lindsay said.

"We hope that in the coming weeks we'll be able to put out some more details on the inactivations of some additional OH-58 units," he said.

Training for active-duty Kiowa officers, warrant officers and enlisted soldiers has been terminated, and the Army has identified the "majority" of existing Kiowa soldiers for transition to another airframe, he said.

There are about 1,400 enlisted soldiers in a Kiowa Warrior MOS, according to data provided by Lindsay. About 700 will receive training for another MOS.

About 840 warrant officers went in front of a recent OH-58D panel; projections call for about 335 to be transitioned to a different aircraft, Lindsay said. This includes the Apache, Black Hawk, CH-47 Chinook or fixed-wing aircraft.

An estimated 20 other warrant officers are expected to transition to unmanned aerial systems.

Retraining for Kiowa officers will depend on their assignments, Lindsay said.

For example, a lieutenant who's a Kiowa pilot who gets sent to the advanced officer course and is later assigned to an Apache unit will be retrained into that aircraft, Lindsay said. A major who's leaving a Kiowa unit for the Pentagon won't receive training for a different aircraft until it's required by his follow-on assignment, Lindsay said.

The Army also is continuing to convert the Apache from the D-model to the E-model, and it has started to transition its training fleet at Fort Rucker, Alabama, to the LUH-72 Lakota from the TH-67, Lindsay said.

In the Army Reserve, the first of two Apache units has already started its conversion into a Black Hawk unit, Lindsay said.

The 8-229 Attack Reconnaissance Battalion, of Fort Knox, Kentucky, has started turning in its Apaches, and is preparing to train its soldiers for "full conversion" to the Black Hawk, he said. The battalion will give up its 24 Apaches and receive 30 Black Hawks.

The conversion is "a long process for the reserve component," Lindsay said.

He expects it will take at least 36 months. The conversion of 8-229 is scheduled to be done in September 2016, he said. The other Reserve Apache battalion, the 1-158th in Conroe, Texas, is scheduled to complete its conversion in 2018.

As for the Guard, where advocates and lawmakers have blasted the Apache conversion, the Army doesn't plan to make any moves until October 2015, which is the beginning of fiscal 2016.

But because of the relatively short timeline, the Army continues to plan while it waits for the outcome of congressional action, Lindsay said.

The 2015 defense authorization bill, which is still pending in Congress, could create a commission to study the Army's force structure and, at least temporarily, stop the transfer of Apaches from the Guard.

Guard advocates and the National Governors Association have been vocal about their opposition to the Army's plans and have called for Congress to ask the Army to suspend the aviation restructuring until a commission can complete its review.

"We are planning and continuing to collaborate with the Guard on the implementation of the aviation restructure as approved by the Secretary of Defense," Lindsay said.

As it looks to carry out the complex restructuring, aviation soldiers across the Army continue to be in high demand.

"The op-tempo is extraordinarily high for Army aviation," Lindsay said. "We have requirements in Afghanistan, in Kuwait, in Iraq, in Liberia, and based on the unpredictable nature of the situation around the world, combined with the drawdown we're experiencing, we think the optempo will remain high for the foreseeable future."

The Army has no choice, however, when it comes to making cuts because of the budget, Lindsay said.

"The Army can't maintain its current aviation structure, the same modernization programs and train the people we need," he said. "That's one of the reasons we've got to make ourselves into the most efficient aviation force that we possibly can so that nothing is wasted, everything is designed to contribute."

Maintaining an aviation capability is expensive but critical, Lindsay said.

"Soldiers and commanders on the ground all understand the game-changing nature of Army aviation and the capability that it brings," he said.