ATLANTA — The Army's Special Operations Command owns some of the most impressive military capability in existence, but even the most impressive stuff has a shelf life, so the command is starting to look at replacing its urban, nimble "street fighter" helicopter.

Maj. Gen. Clayton Hutmacher, the deputy commander of US Army Special Operations, said at the Army Aviation Association of America's Mission Solutions Summit on Saturday that replacing the MH-6 Little Bird light-assault helicopter won't be easy for a variety of reasons.

"It really comes down to money for us," Hutmacher said. "If it's Army common, it's paid for under … Army dollars, so if we get a Black Hawk from the Army, Army pays for that. What we do to it after we get it, SOCOM pays for that."

The Army has the luxury of economy-of-scale, according to Hutmacher. The service is able to buy a lot of equipment and drive the price per unit down. "Special operations doesn't have that luxury."

When Special Operations needs to replace its Little Bird — which amounts to about 70 helicopters, including spares — going it alone to buy such a small amount wouldn't be affordable when up-front development costs are factored in, Hutmacher explained.

The Army has no Little Birds in its inventory and does not have a need to procure them based on its current roles and operating concept.

For what Special Operations lacks in budget, it makes up for in agility, being able to procure, beef up what it's given and get it out into the field quickly, Hutmacher added.

For now, the command is upgrading the Little Bird with a Block III configuration that will expand the service life of the aircraft to 2020 and beyond. But, Hutmacher said, "my personal opinion on this is that we are probably reaching the point where we need to look at a new airplane after Block III."

It will be critical to "preserve capability we get out of Little Bird," he said, and trades can't be made in its size.

Hutmacher hearkened back to the Little Bird's use in the Battle of Mogadishu in 1993 where "we landed in the street. We land in streets all the time."

The Little Bird's rotor diameter, he noted, is 27 feet and 3 inches, and the UH-60 Black Hawk's is nearly double that.

"I don't know if it's realistic to stay in that footprint, but we've got to stay well below the footprint of a Black Hawk," Hutmacher said.

But there are problems with the Little Bird, he noted. For one, the aircraft is so small it has limited range and is even more limited if it is carrying a full complement of special forces. "That drives our basing," he said.

Referring back to Mogadishu, Hutmacher said the Little Bird had to be flown in and out of the airport, which meant the enemy had eyes on them all the time.

"I think when we take a look at a future Little Bird, what we want to do is improve our ability to stand off farther from a target, that makes it easy for us to maintain the element of surprise and it makes the problem set even more difficult," Hutmacher said. "The farther away we are, the farther it is for them to defend against us and operational security and maintain tactical surprise is easier."

The Little Bird is also slow. Typically its speed is about 80 knots and could potentially be pushed to 100 knots. "The future of Little Bird should have airspeed, [it] should be a significant factor in how we approach it," he said.

And if the Little Bird can be faster, it could allow for changes in the requirement that it must fit into a C-130 aircraft.

"If we are able to get a Little Bird replacement with speeds, I would say, 200 knots or greater, my personal opinion is, we can move away from a C-130 load requirement because we are flying as fast as a C-130," Hutmacher said. The operators would have more flexibility if it could be transported using a C-17, he added.

Even with his wish list for the aircraft, Hutmacher acknowledged, "fiscally it's not achievable by ourselves and the Army has got different requirements than SOCOM. We have to work with the Army ... and be willing to compromise."

Aside from traditional budgetary and acquisition woes, the Little Bird's replacement could be hindered even further by a few things the Army is pursuing that works against Special Operations requirements for a new helicopter. For one, the service retired its Kiowa Warrior helicopter, an aircraft sized between the Little Bird and the Black Hawk.

The Army is also leaning heavily toward replacing its medium-lift aircraft first when it starts building a Future Vertical Lift aircraft expected to start fielding in the 2030s.

There's been much debate about whether the Army should choose to build a light reconnaissance helicopter first or a medium-lift variant.

Some believed the Army would build a lighter helicopter first to fill the gap left over from when the service decided to retire the Kiowa. The service is filling that gap temporarily by teaming AH-64 Apache Attack helicopters with Shadow unmanned aircraft systems.

But speaking to Defense News at the AAAA summit, Maj. Gen. William Gayler, the Army Aviation Center of Excellence commander at Fort Rucker, said the first variant for FVL would be medium-lift.

Since the program is joint and the Marine Corps and Air Force have much more interest in building the medium-lift helicopter — to be part of a family of systems — the Army thinks it's the right answer to first field a medium variant, he said.

There are a few attractive options for a Little Bird replacement under development through the Joint Multi-Role Technology Demonstrator (JMR TD) program that will help inform the Army's requirements for the FVL program of record that is expected to kick off in 2019.

A Sikorsky-Boeing team has been refining Sikorsky's X2 coaxial rotor technology, which increases the helicopter's speed to 220 knots and has increased maneuverability and nimble hovering capability. While Defiant, the aircraft designed to fly in the 2017 Army JMR TD flights, is likely too large for special operators, its predecessor, Raider, could potentially fit in the weight class.

And there's plenty of proof there are other helicopters out there that could, in some way, meet the criteria — many which auditioned in flight tests the last time the Army tried to replace its Kiowa armed scout.

There's the obvious AH-6 Little Bird from Boeing and aircraft from AgustaWestland and MD Helicopter, as well as Airbus' LUH-72X+ Lakota and souped-up Kiowa Warriors from Bell Helicopter.

But even if there was something out there that met all the criteria for a new Army Special Operations Little Bird, there's still the issue of affordability.

"So I think we've got to work closely with Army aviation, both on the requirements side and on the acquisition side," Hutmacher said, "and figure out what is in the art of the possible."

Brig. Gen. Erik Peterson, commander of Army Special Operations Aviation Command, told Defense News in a brief interview that "we have a strong road map" for Little Bird "that carries us easily 10 to 15 years."

The command is "keeping our eyes open, continuing to do industry studies, drive science and technology for either unilateral [commercial, off-the-shelf] replacements, a purpose-built unilateral option of some sort, and a combined effort potentially in conjunction with Future Vertical Lift or some other effort that the Army may pursue for light reconnaissance and light attack," Peterson said. "We are not casting our lot in any single effort at this point."

The bottom line, he said, "is the 15- to 20-year horizon, we think we will have to do something substantially different and we think that we are at a pretty good place for helping drive that and frame those options."

Twitter: @JenJudson