ATLANTA — The US Army's aviation force should embody the Army Operating Concept — its mission describes the doctrine to a T — but as its aircraft age, budgets shrink and its size grows smaller, service leaders question whether the fleet can keep up.

The four-star Gen. David Perkins, the Army's Training and Doctrine Command commander, described the world as increasingly complex, full of unknowns and unpredictable, but said the Army will be guided by several principles in order to be successful in future conflicts. Gen. David Perkins, the Army's Training and Doctrine Command commander, The four-star general said at the Army Aviation Association of America’s Mission Solutions Summit last week that Army aviation aligns exactly with how the Army expects to operate in the future as outlined in its operating concept released in the fall of 2014.

Using a slide to outline those principles of how to "Win in a Complex World" — which is also the title of the Army's operating concept released in 2014 — Perkins said the Army has to be able to maneuver from multiple locations and domains. The Army also wants to present multiple dilemmas to the enemy, so the enemy is unable to adapt.

Additionally, he said, the service must be able to support units dispersed over large areas. Finally, the Army wants to be able to give commanders multiple options, which puts them in a position of advantage.

Perkins said that is exactly what Army aviation is meant to do: It covers all domains, connects ground forces in areas over a large theater, presents multiple dilemmas to the enemy and provides multiple options for the commander.

But there's a growing rate of instability in the world, Maj. Gen. William Gayler, the service's new Army Aviation Center of Excellence commander at Fort Rucker, Alabama, said at AAAA. "Now that instability continues to move, but resourcing is divergent from that."

The Army is dropping to a force of 980,000 while demand for the service's support has not gone down, he added. Nor are there any signs budget problems will be solved quickly.

Looking back on 15 years of war, Gayler said, "We've just had some staggering success, we've flown over 20 million flight hours as a branch. We are constantly deployed today," but," we paid tremendous costs in treasure to meet that demand."

And America's adversaries have "been going to school on everything we are doing," Gayler said.

And over time, gaps have widened. "We need to fill those gaps with what I call reach, protection and lethality," Gayler said. "Reach, to me, is I want to deny sanctuary to any adversary in terms of power, range, speed, endurance and the ability to get them regardless of a weather condition or environmental condition. Reach, it's the only way to enable the Army Operating Concept."

But the ability to have that reach is being threatened.

The Army's helicopters are gaining weight — in the case of the Black Hawk, 78 lbs a year — and despite upgrades and technology refreshes, its getting harder for those aircraft to fly anywhere on the planet.

The Army is currently only able to fly in 84 percent of the world with the current existing power generation in its helicopters. In Afghanistan alone, Army aircraft can only fly in about 47 percent of the country.

"We've been growing and gaining weight for all the rights reasons," Gayler, said. "Every new technology, everything designed to protect a crew or its passengers, but we've given maneuverability at the objective away. We've given away payload, we've given away ammo, we are limiting options to a commander, we are not giving options. We do give options if the weather's right but if the weather's not right, we can't give options," he lamented.

Gayler warned if things don't go a different direction, the aviation branch may not meet the requirements laid out in the concept.

"We are capable of giving commanders options, but we also sometimes give a limitation and we gotta fix that," Gayler added.

The Army needs to make drastic improvements in its helicopters in order to give back capability to its aviation branch in order to align with the AOC.

Major helicopter fleets like UH-60s and AH-64s are expected to stick around for nearly 100 years. The CH-47 Chinook cargo helicopter is scheduled to retire in 2064.

"I would argue that our current airframes have reached the feasible evolutionary limit to meet the Army Operating Concept," he said. "We can certainly do things to make them go a little faster, make them stay a little longer, but not to the duration, range or times we need to execute," the concept.

This is why bringing on the Improved Turbine Engine Program (ITEP) is so important, Gayler stressed. With ITEP, the Army's aircraft will be able to reach 96 percent of the globe.

The ITEP engine will replace engines in Black Hawks and Apaches initially. The service plans to reach low rate initial production on the engine in 2024. The program was delayed for several years until the Army finally moved forward last fall and released a request for proposals to industry.

And it's imperative the Army continue to invest in technology to better protect helicopters, according to Steffanie Easter, the Army's principal deputy to the service's acquisition chief.

Aside from investing in a new engine, developing other technologies that could help pilots fly in brownouts and other low-visibility scenarios are critical, she added.

After many years of stressing the importance of solving the degraded visual environment (DVE) problem, the Army is resurrecting its materiel solution called the Brownout Rotorcraft Enhancement System (BORES) to incrementally solve the issue.

The Army wants to reach an engineering and manufacturing development phase and a production phase through the start of full-rate production all in the next five years.

Additionally, Easter said bringing the Hellfire missile's replacement — the Joint Air-to-Ground Missile — into the force is a priority in order to improve stand-off distances helicopters can fly in order to hit a target. JAGM provides precision accuracy to hit both moving and fixed targets and will be effective against a variety of countermeasures, she noted.

Easter said the Army is also investing in fiscal 2017 in developing assured position navigation and timing (PNT) enablers. The service is trying to understand the vulnerabilities to its GPS and is conducting modeling, simulation and testing on current systems. Easter said the hope is to reach an initial operational capability in the 2021 time frame.

On the maintenance side, relying too heavily on contractors, as the service has done in 15 years of war, is also incongruous to the Army's operating concept requiring it to be more expeditionary. Soldier maintainers should not be staying back at home station while the rest of a unit deploys. And contractors can't be relied upon to deploy to the middle of nowhere, according to Brig. Gen. Bob Marion, the Army's aviation program executive officer.

The Army wants to find the right balance between when it uses soldier and contract maintainers for its fleet of aircraft, but right now the levels are "out of balance," according to the new Army Aviation and Missile Life Cycle Management Command (AMCOM) leader.

"I think we are contractor heavy," Brig. Gen. Doug Gabram said at AAAA. "I think we've lost the maintenance management skills of our soldiers."

Twitter: @JenJudson