Navy spokesmen could not say Wednesday if anyone on the ground was alarmed by the drone — officially an MQ-8B Fire Scout Vertical Takeoff and Landing unmanned aerial vehicle — which looks like a small windowless helicopter and was flying at 2,000 feet. The Navy did say that the drone buzzed the capitol repeatedly before operators were able to re-establish control and guide it back to its base in southern Maryland.

Still, the Aug. 2 incident resulted in the grounding of all six of the Navy’s Fire Scouts as well as an inquiry into what went wrong. The Navy is calling the problem a “software issue” that foiled the drone’s operators.

Or, as Cmdr. Danny Hernandez, a Navy spokesman, put it: “When they lose contact with the Fire Scout, there’s a program that’s supposed to have it immediately return to the airfield to land safely. That did not happen as planned.”

Navy spokesmen said the Fire Scout, made by Northrop Grumman, was a little more than an hour into a test flight operating out of Naval Air Station Patuxent River on the Chesapeake Bay when operators lost its control link. The drone then flew 23 miles on a north-by-northwest course to enter Washington’s restricted airspace. A half-hour later, Navy spokesmen said, operators re-established control and the drone landed safely back at Patuxent.

The Navy did not describe the scene inside the ground control station as operators sought to re-establish communication with the drone.

The Fire Scout, about 31 feet long and 10 feet high, is a surveillance aircraft that can take off from Navy warships. In April, a Fire Scout was part of a drug arrest in the waters off Central America. According to the Navy, the Fire Scout relayed video of a suspicious fishing vessel to the Coast Guard and law enforcement officials, who moved in and seized 60 kilos of cocaine.

An unnamed drone pilot/operator, who is not authorized to speak for Patuxent River NAS or for the Navy, disclosed that the drone involved in the D.C. airspace violation was not the surveillance version, but was an armed reconnaissance variant, designed to operate in "swarms" behind enemy lines.

The scores of the drones, if not hundreds, are to be launched against enemy rear areas, logistics lines and headquarters. they are to perform armed reconnaissance, attacking targets of opportunity which they will identify by a highly classified intelligence algorithm. They are intended to operate autonomously, with minimal guidance from drone operators who will be controlling as many as a dozen of the aircraft.

Testing of the drones from Patuxent River NAS has been strictly one drone under the positive command of one operator, but there have been several incidents of the drone's autonomous controls taking command and (usually) heading toward Washington. Intelligence officers are testing the software to determine if the detectors/measurements of un-American activity are set too sensitively.

Until the problem is resolved, further drone testing is to be moved to the Pacific Missile Test Range on Kauai.