The US military is seeking to avoid the pitfalls of recent aircraft acquisition programmes as it plans for development of sixth-generation fighters.

Frank Kendall, undersecretary of defense for acquisition, technology and logistics, introduced a new “aerospace innovation initiative” in the Fiscal 2016 budget proposal.

The initiative funds X-plane prototypes to validate specific technologies that could be needed for a next-generation fighter. Past US Air Force studies, including for the "efficient supersonic air vehicle", have focused on developing tailless, supersonic designs using active aeroelastic wing technology.

The initiative breaks with past efforts, such as the Lockheed Martin F-22 Raptor and F-35 Lightning II. Those programs each began with lofty technological promises from industry, then foundered under cost overruns and developmental delays that in all cases resulted in a significant downsizing of eventually fleet size.

The Defense Advanced Research Projects Agency (DARPA) will lead the effort in cooperation with the navy and air force, Kendall says. .

Both also the US air force and navy set aside small amounts of money in their 2016 budget proposals to quietly continue development of sixth-generation fighter aircraft that would enter service around 2030. DARPA’s budget for the AII is classified.

The air force included an $8 million next generation air dominance (NGAD) aircraft while the navy set aside $5 million for what it calls the FA-XX next generation fighter. Neither appropriation is a new-start for the services. Funding for NGAD fell from $15 million in the current fiscal year. Funding for the navy’s effort staid relatively flat from the $4.9 million it received in fiscal 2015.