Military eyes sixth-generation fighter.

• Author: Tadjdeh, Yasmin

As key Air Force and Navy fighter jets--such as the F-22 Raptor and F/A-18E/F Super Hornet--face the end of their service lives in the 2030s, work is being done in earnest by the two services to field a new fighter.

The sixth-generation fighter, as it has been called, is still largely conceptual. While the services have ideas about some requirements and industry has already begun distributing artist renditions of potential aircraft, a formal program is still years away.

Sterling Anderson, deputy chief of Air Combat Command's air superiority core function team, told National Defense that the Air Force already has a few capabilities in mind.

The service wants to cut down on the amount of mid-air refueling, he said. Fighters, which are traditionally small and compact, often have less space for extra fuel, he noted.

"We think it's going to have to be long range, for sure," he said. "If you look at almost any part of the world, even in the Middle East, and look at some of the distances required and the tankers required, we would like to have a fighter with a longer range probably than the standard 500 miles that we have today."

Since the end of the Cold War, combat aircraft have had the luxury of operating from bases that are close to the enemy, like in Iraq, said Mark Gunzinger, a senior fellow at the Center for Strategic and Budgetary Assessments, a Washington, D.G-based think tank. In the future, where enemies have precision-guided weapons like cruise or ballistic missiles, those bases could be at high risk.

"We might need to operate our future combat air forces from great distances from an enemy in areas that are not at such risk," he said.

However, that doesn't necessarily mean that the Air Force will go for a larger aircraft that resembles a bomber, Anderson said. "We're working on a lot of really advanced propulsion technologies ... that are going to have a pretty good... increase in specific fuel consumption, so even keeping aircraft fairly small, we believe we are going to be able to get some pretty good range increases."

An aircraft as big as a bomber would likely be extremely expensive, he said. "That's probably out of reach to be that big. It's just not affordable."

Stealth will also be a key requirement, he added. It "is the price of admission in future conflicts."

Additionally, the service wants to field smaller weapons.

"One of the issues we have today is just the amount of weapons we can carry on any given fighter," he said. "The...