Ok, so it's not remotely a UAV, but Boeing's proposed replacement for the 707-based E-8 Joint STARS radar jets would do an awful lot of what we've come to associate with drones -- spying-on and killing bad guys.
As you may know, Boeing is pitching a new ground-scanning radar jet called P-8 Airborne Ground Surveillance based on the Navy's P-8 Poseidon subhunter. If the plane is ever built and lives up to Boeing's promises it will be able to scan giant swaths of the battlefield using a powerful APY-7 radar to find moving vehicles and take synthetic aperture pictures of the Earth. It will also be able to use high-resolution electro-optical/infrared cameras to zoom in on specific targets. Meanwhile, analysts in the back of the plane can pour over the data collected by its sensors or info from ground centers and possibly those of nearby UAVs -- in real time. It can also feed intelligence back to an intelligence center or cue UAVs or fighters to attack bad guys. If a target needed to be hit immediately, P-8 AGS could drop a prescison-guided bomb from its internal weapons bay or one of four wing hardpoints that are wired to carry munitions. This is pretty close to "a single platform kill chain" -- Boeing's ad slogan for the plane.
Now, whether or not all this capability is needed in one large airplane is up for debate. (Technically, an F-16 equipped with a targeting pod can do a lot of what we talked about above.) And remember, a plane like this wouldn't be very safe loitering close to a ground fight in a war where U.S. air dominance wasn't absolute. Still, this concept fits the Pentagon's notion that all "sensors need to be shooters and all shooters need to be sensors."
(Watch Boeing's concept video for P-8 AGS at the end of this piece.)
The Air Force is wrapping up a study on possible replacements for the aging E-8 JSTARS' in the ground scanning mission. That study is looking at everything from using big jets -- like the E-8 or P-8 -- to small business jets like the RAF's Sentinel R1 as well as drones or blimps.
Keep in mind that the Air Force is still working on replacing the E-8's ancient JT3C engines with a newly-made JT8D engines (though the JT8D was first built in the early 1960s and will go out of production soon). That effort is still in the test phase and its future is still unknown.
(Also remember that investment in ISR tech is one of the areas that senior Air Force leaders said that they will fight to protect from budget cuts in the coming years.)
Here's Boeing's promo video for the P-8 AGS: