The high cost of the F-22 was driven by stealthy features, including a small weapons bay. Credit: U.S. Air Force

Eyeing emerging threats amid a constrained budget environment, and consumed by theLockheed Martin F-35’s high cost, the U.S. Air Force is already studying what the “sixth-generation” of air dominance capability for the service should be.
Air Combat Command Chief Gen. Mike Hostage says he is agnostic on whether the next generation of Air Force combat capability should be manned, unmanned or even a fighter. “It isn’t necessarily another single-seat fighter,” he said July 29 at a breakfast in Washington. “If it is the enter button on the keyboard that makes all the adversaries fall to the ground, I’m okay with that.”
Because of the “torturous” nature of the acquisition process, “we are already behind the line to get something on the ramp,” he said. “I think it is existential that we build the future fleet.” Hostage says he is willing to accept risk in the interim by shifting money from upgrades to existing fighters to provide seed money for the so-called sixth-generation system. This includes scrapping plans for the Combat Avionics Programmed Extension Suite and structural work for the F-16s expected to remain in the fleet despite downsizing.
This “sixth-generation” system is so dubbed as a follow-on to the “fifth-generation” of stealth, speed and avionics/sensor fusion offered by the F-22 and F-35. It will have to operate with the forthcoming Long-Range Strike Bomber; the Air Force recently issued a request for proposals for 80-100 stealthy aircraft, according to Air Force Chief of Staff Gen. Mark Welsh. This kicks off a long-awaited competition between a Boeing/Lockheed Martin team and Northrop Grumman, with a goal of a unit price at or under $550 million.
Still, the all fifth-generation fleet once envisioned by the Air Force remains elusive. Flight restrictions on the F-35 are “near-term,” and Hostage does not think the root cause of the excessive friction in the third stage integrally bladed rotor in the low-pressure turbine that led to a June 23 F-35A F135 engine fire will jeopardize achieving the Air Force’s initial operational capability for the single-engine stealthy jet, planned by August 2016.
The fire prompted a fleet-wide grounding for three weeks, followed by a limited flight envelope for all three variants of the aircraft. For two weeks they have been flying only in a limited envelope, hampering progress in flight testing, including the weapons releases required for the U.S. Marine Corps to declare initial operational capability in one year with the F-35B. Operational aircraft are limited to 0.9 Mach and -1 to 3g under normal acceleration. Flight-test jets are approved for a slightly more rigorous 1.6 Mach and -1 to 3.2g under recently relaxed guidelines.
Hostage acknowledges that the “magazine” for today’s fifth-generation fighters-—the F-22 and, eventually, the F-35—is shallow. Each can carry only a maximum of eight ground-attack Small-Diameter Bombs. Physics limits magazine options for these aircraft, as the stealthy design requires small internal weapons bays.
Hostage hinted, however, that the Pentagon is funding classified efforts to maximize firepower. At one point, the service pursued the so-called Joint Dual-Role Air Dominance Missile (JDRADM), meant to combine the air-to-air capabilities of the Amraam with the radar-killing air-to-ground attack capabilities of the HARM missile into one airframe. That project—later dubbed the Next-Generation Missile—fizzled; some sources suggest research may be continuing under a classified program.
And it is likely the service will pursue directed-energy options for the sixth-generation system. “Amazing developments in the [directed energy] arena” have been made and this technology “holds great promise,” Hostage said. He did not provide details on programmatics and added that it was not clear yet whether directed-energy capabilities would be mature enough to deploy on the sixth-generation system. 
Directed energy is one of five areas highlighted by the Air Force as investment items for the future fleet; also included were unmanned aerial vehicles, nanotechnology, hypersonics and automation. These are included in a new paper, “America’s Air Force: A Call to the Future,” which outlines a strategic framework against which the service plans to budget for decades to come.