Northrop Grumman reports that its high altitude long endurance unmanned aerial vehicles have achieved a flight-hour milestone.

The RQ-4 Global Hawk, flown by the U.S. Air Force, and other company HALE systems flew more intelligence, surveillance and reconnaissance mission hours in one week last September for the U.S. government than ever before -- 781 hours.

The RQ-4 Global Hawk flew 87 percent of the missions. The U.S. Navy's Broad Area Maritime Surveillance Demonstration aircraft and NASA's Global Hawk hurricane research UAS contributed to the record.

"There are at least two Global Hawks in the air at all times providing indispensable ISR information to those that need it," said Mick Jaggers, Global Hawk UAS program director, Northrop Grumman Aerospace Systems. "The 2014 fiscal year was the most active yet for the Global Hawk, with a 40 percent year over year increase in flight hours."

Northrop Grumman said its HALE UAS series have so far flown more than 130,000 total flight hours, with 75 percent of those hours in support of combat/operational missions.

Two new RQ-4 Global Hawk aircraft were delivered to the Air Force last fall, bringing the service's fleet of the UAS to 33. Three more are scheduled for delivery in 2016 and 2017.