But as the military wound down its presence in the Middle East, plans for the unmanned floating spy center deflated. The aircraft fell behind schedule, became 12,000 pounds overweight and was ultimately canceled after just one test flight.

Last month, the Pentagon quietly decided to sell back the sophisticated spyship to the British company that built it for $301,000 — a fraction of its investment.

The U.S. Army‘s Long Endurance Multi-Intelligence Vehicle was initially touted as a revolutionary aviation concept that would give troops on the ground an uninterrupted view of the war zone.

Now, in the current federal budget environment, the program stands as an example of military waste. …

That gave rise to the idea for an unmanned airship, with its ability to linger over an area for a long time.

In June 2010, the Army signed a contract with the British firm Hybrid Air Vehicles Ltd. and Falls Church, Va., military giant Northrop Grumman Corp. to develop as many as three aircraft. If the Army went through with this plan, costs would have climbed to $517 million. …

The airship involved subcontractors from more than 18 states and at least three countries. It was designed, built and flown in 26 months from the contract award.

Aside from falling eight months behind its initial schedule, the airship had other problems, according to a report by the Government Accountability Office. Last year, the GAO said it was “about 12,000 pounds overweight because components, such as tail fins, exceed weight thresholds.”

The GAO said the increased weight reduced the airship’s estimated endurance “at an altitude of 20,000 feet from the required 21 days, to 4 to 5 days.”

In its first and only flight, the airship flew for more than 90 minutes above Lakehurst Naval Air Station in New Jersey in August 2012. The airship had a pilot onboard.