Gen. Herbert "Hawk" Carlisle of the US Air Force recently declared a squadron of 15 unmanned F-16s operationally capable, IHS Jane's reports.

These drone versions of the F-16, called QF-16s, will provide targets for the Air Force as it tests out new weapons capabilities of the F-35 Joint Strike Fighter.

"The QF-16 Full Scale Aerial Target will provide the next generation of combat training and testing for US warfighters," a Boeing statement on the drones said.

While the old F-16s may seem like costly targets, the Air Force is touting them as a more realistic opponent than what was previously available, and they are economical to some extent because they're made from older, retired F-16 airframes.

"The QF-16 will replace the existing QF-4 fleet and provide a higher-capability, fourth-generation aerial target that is more representative of today's targets and threats," the Boeing statement continued.

Having realistic targets to train against will help the F-35 pilots. F-35 Joint Program Office

"This leap forward in airframe capabilities, combined with advanced electronic pods, will allow us to properly test and evaluate our 5th generation aircraft and weapons," Lt. Col. Matthew Garrison, the commander of the 82nd Aerial Target Squadron at Tyndall Air Force Base in Florida, told C4ISRNET in an email.

In fact, an F-35 already participated in a test in which a QF-16 drone was shot down, though it did so with an SM-6 missile fired from a land-based silo.