Subscribe
U.S. Navy Sailors assist in loading the X-47B Unmanned Combat Air System (UCAS) demonstrator aboard the aircraft carrier USS Harry S. Truman (CVN 75) on Nov. 26, 2012.

U.S. Navy Sailors assist in loading the X-47B Unmanned Combat Air System (UCAS) demonstrator aboard the aircraft carrier USS Harry S. Truman (CVN 75) on Nov. 26, 2012. (Lorenzo J. Burleson/U.S. Navy)

U.S. Navy Sailors assist in loading the X-47B Unmanned Combat Air System (UCAS) demonstrator aboard the aircraft carrier USS Harry S. Truman (CVN 75) on Nov. 26, 2012.

U.S. Navy Sailors assist in loading the X-47B Unmanned Combat Air System (UCAS) demonstrator aboard the aircraft carrier USS Harry S. Truman (CVN 75) on Nov. 26, 2012. (Lorenzo J. Burleson/U.S. Navy)

Chief of Naval Operations (CNO) Adm. Jonathan Greenert, left, and Secretary of the Navy (SECNAV) Ray Mabus observe an X-47B drone make the historic first unmanned aircraft landing at sea from the flight deck of the USS George H.W. Bush aircraft carrier July 10, 2013.

Chief of Naval Operations (CNO) Adm. Jonathan Greenert, left, and Secretary of the Navy (SECNAV) Ray Mabus observe an X-47B drone make the historic first unmanned aircraft landing at sea from the flight deck of the USS George H.W. Bush aircraft carrier July 10, 2013. (Tony D. Curtis/U.S. Navy)

A Navy program that twice landed a combat drone successfully on an aircraft carrier last week aborted its last attempt on Monday, the program’s second scrubbed effort in four tries during a period of testing at sea.

Naval Air Systems Command said in a statement that an X-47B, an unmanned drone with a 62-foot wingspan and a range of 2,400 miles, experienced a “minor test instrumentation issue” during its flight toward USS George H.W. Bush in the Atlantic and returned to Naval Air Station Patuxent River, in nearby Maryland.

The command nevertheless deemed the sea trials a success, saying in the statement they showed the Navy was ready to move ahead with “unmanned carrier aviation.”

The drone that flew Monday, dubbed “Salty Dog 501,” was not the same craft that made two out of three landing attempts on July 10. That craft, Salty Dog 502, aborted its third landing after self-detecting a navigation anomaly, and touched down at a nearby airfield, according to the Navy.

Last week’s successful landings were the first ever for an unmanned drone on an aircraft carrier and marked the culmination of the program’s testing on the carrier. Secretary of the Navy Ray Mabus and Chief of Naval Operation Jonathan W. Greenert both attended.

“The X-47B represents our future and it is an important step towards the next unmanned system which will join our carrier air wings,” Greenert later posted on his Facebook page.

The Navy cast a positive light on last week’s aborted landing, noting the aircraft detected the problem. Whether that was also the case with Monday’s glitch was unclear, although a spokeswoman for the command said it was en route to the carrier when the problem occurred and not in the act of landing.

Testing of the X-47B by the Navy’s Unmanned Combat Air System Demonstration in recent days has included arrested landings, flight deck operations, steam catapults and hot refueling, according to the statement. Air refueling operations are scheduled for 2014.

Monday’s attempt was the last with the ship, which since returned to to its home port in Norfolk, Va.

Defense contractor Northrop Grumman designed and produced the two aircraft under a 2007 contract with the Navy.

beardsley.steve@stripes.com Twitter: @sjbeardsley

Sign Up for Daily Headlines

Sign up to receive a daily email of today's top military news stories from Stars and Stripes and top news outlets from around the world.

Sign Up Now